US20070011667A1 - Lock management for clustered virtual machines - Google Patents

Lock management for clustered virtual machines Download PDF

Info

Publication number
US20070011667A1
US20070011667A1 US11/442,523 US44252306A US2007011667A1 US 20070011667 A1 US20070011667 A1 US 20070011667A1 US 44252306 A US44252306 A US 44252306A US 2007011667 A1 US2007011667 A1 US 2007011667A1
Authority
US
United States
Prior art keywords
lock
virtual machine
application
object
central manager
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US11/442,523
Inventor
Saravanan Subbiah
Timothy Eck
Steven Harris
Orion Letizi
Original Assignee
Saravanan Subbiah
Eck Timothy S
Harris Steven T
Letizi Orion D
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to US68461005P priority Critical
Application filed by Saravanan Subbiah, Eck Timothy S, Harris Steven T, Letizi Orion D filed Critical Saravanan Subbiah
Priority to US11/442,523 priority patent/US20070011667A1/en
Publication of US20070011667A1 publication Critical patent/US20070011667A1/en
Application status is Abandoned legal-status Critical

Links

Images

Classifications

    • GPHYSICS
    • G06COMPUTING; CALCULATING; COUNTING
    • G06FELECTRIC DIGITAL DATA PROCESSING
    • G06F9/00Arrangements for program control, e.g. control units
    • G06F9/06Arrangements for program control, e.g. control units using stored programs, i.e. using an internal store of processing equipment to receive or retain programs
    • G06F9/44Arrangements for executing specific programs
    • G06F9/455Emulation; Interpretation; Software simulation, e.g. virtualisation or emulation of application or operating system execution engines
    • G06F9/45504Abstract machines for programme code execution, e.g. Java virtual machine [JVM], interpreters, emulators
    • GPHYSICS
    • G06COMPUTING; CALCULATING; COUNTING
    • G06FELECTRIC DIGITAL DATA PROCESSING
    • G06F16/00Information retrieval; Database structures therefor; File system structures therefor
    • G06F16/20Information retrieval; Database structures therefor; File system structures therefor of structured data, e.g. relational data
    • G06F16/21Design, administration or maintenance of databases
    • G06F16/217Database tuning
    • GPHYSICS
    • G06COMPUTING; CALCULATING; COUNTING
    • G06FELECTRIC DIGITAL DATA PROCESSING
    • G06F16/00Information retrieval; Database structures therefor; File system structures therefor
    • G06F16/20Information retrieval; Database structures therefor; File system structures therefor of structured data, e.g. relational data
    • G06F16/24Querying
    • G06F16/245Query processing
    • G06F16/2455Query execution
    • G06F16/24552Database cache management
    • GPHYSICS
    • G06COMPUTING; CALCULATING; COUNTING
    • G06FELECTRIC DIGITAL DATA PROCESSING
    • G06F9/00Arrangements for program control, e.g. control units
    • G06F9/06Arrangements for program control, e.g. control units using stored programs, i.e. using an internal store of processing equipment to receive or retain programs
    • G06F9/46Multiprogramming arrangements
    • G06F9/52Program synchronisation; Mutual exclusion, e.g. by means of semaphores
    • GPHYSICS
    • G06COMPUTING; CALCULATING; COUNTING
    • G06FELECTRIC DIGITAL DATA PROCESSING
    • G06F9/00Arrangements for program control, e.g. control units
    • G06F9/06Arrangements for program control, e.g. control units using stored programs, i.e. using an internal store of processing equipment to receive or retain programs
    • G06F9/46Multiprogramming arrangements
    • G06F9/52Program synchronisation; Mutual exclusion, e.g. by means of semaphores
    • G06F9/526Mutual exclusion algorithms
    • GPHYSICS
    • G06COMPUTING; CALCULATING; COUNTING
    • G06FELECTRIC DIGITAL DATA PROCESSING
    • G06F9/00Arrangements for program control, e.g. control units
    • G06F9/06Arrangements for program control, e.g. control units using stored programs, i.e. using an internal store of processing equipment to receive or retain programs
    • G06F9/46Multiprogramming arrangements
    • G06F9/54Interprogram communication
    • G06F9/544Buffers; Shared memory; Pipes
    • GPHYSICS
    • G06COMPUTING; CALCULATING; COUNTING
    • G06FELECTRIC DIGITAL DATA PROCESSING
    • G06F11/00Error detection; Error correction; Monitoring
    • G06F11/07Responding to the occurrence of a fault, e.g. fault tolerance
    • G06F11/14Error detection or correction of the data by redundancy in operation
    • G06F11/1479Generic software techniques for error detection or fault masking
    • GPHYSICS
    • G06COMPUTING; CALCULATING; COUNTING
    • G06FELECTRIC DIGITAL DATA PROCESSING
    • G06F11/00Error detection; Error correction; Monitoring
    • G06F11/07Responding to the occurrence of a fault, e.g. fault tolerance
    • G06F11/16Error detection or correction of the data by redundancy in hardware
    • G06F11/20Error detection or correction of the data by redundancy in hardware using active fault-masking, e.g. by switching out faulty elements or by switching in spare elements
    • G06F11/202Error detection or correction of the data by redundancy in hardware using active fault-masking, e.g. by switching out faulty elements or by switching in spare elements where processing functionality is redundant
    • G06F11/2023Failover techniques
    • G06F11/203Failover techniques using migration
    • GPHYSICS
    • G06COMPUTING; CALCULATING; COUNTING
    • G06FELECTRIC DIGITAL DATA PROCESSING
    • G06F2209/00Indexing scheme relating to G06F9/00
    • G06F2209/52Indexing scheme relating to G06F9/52
    • G06F2209/522Manager
    • GPHYSICS
    • G06COMPUTING; CALCULATING; COUNTING
    • G06FELECTRIC DIGITAL DATA PROCESSING
    • G06F9/00Arrangements for program control, e.g. control units
    • G06F9/06Arrangements for program control, e.g. control units using stored programs, i.e. using an internal store of processing equipment to receive or retain programs
    • G06F9/44Arrangements for executing specific programs
    • G06F9/445Program loading or initiating

Abstract

Technology for sharing data among multiple virtual machines in a cluster of virtual machines is disclosed. Each virtual machine identifies “managed” objects of an instance of an application running at the virtual machine. Operations performed by an instance of one application which affect the state of managed objects are detected and distributed. Centralized lock management is provided where a cluster virtual machine requests a lock which affects managed object, and communicates a request to the central manager for the lock. A central manager determines whether the lock is available, and if it is, grants the lock to the virtual machine. The central manager grants the lock to the requesting virtual machine when no other virtual machine currently has the lock.

Description

    CROSS REFERENCE TO RELATED APPLICATION
  • This application claims the benefit of U.S. provisional patent application No. 60/684,610, filed May 25, 2005, titled “Terracotta Virtualization Server”, and incorporated herein by reference.
  • The application is also related to the following co-pending applications, each of which is incorporated herein by reference:
  • (1) U.S. patent application Ser. No. ______, filed ______, titled “Clustering Server Providing Virtual Machine Data Sharing”, docket no. TERA-01001US0;
  • (2) U.S. patent application Ser. No. ______, filed ______, titled “Distributed Signaling Between Threads On Different Virtual Machines”, docket no. TERA-01001 US0;
  • (3) U.S. patent application Ser. No. ______, filed ______, titled “Creating Synthetic Transactions at a Virtual Machine”, docket no. TERA-01002US0.
  • (4) U.S. patent application Ser. No. ______, filed ______, titled “Distributing Object Identity Cluster-Wide Among Multiple Virtual Machines”, docket no. TERA-01003US0;
  • (5) U.S. patent application Ser. No. ______, filed ______, titled “Distributing Objects By Distributing Underlying Actions”, docket no. TERA-01004US0;
  • (6) U.S. patent application Ser. No. ______, filed ______, titled “Sharing Object State Across Virtual Machines Using Logical Collections”, docket no. TERA-01005US0.
  • BACKGROUND
  • Application developers have traditionally faced a number of challenges in horizontally scaling applications to multiple servers. Scaling is particularly useful to World Wide Web application developers who may, for example, require geographically distributed application servers to provide users with better performance. In one example, suppose a user of a web-based application logs on to a web site to change information in an existing user account. Typically, in a distributed application, one application server is selected to handle the transaction based on its geographical location, availability or other factors. The selected server accesses the account data and makes the requested changes locally and the updated data must then be shared with the other servers so that the user's future interactions with any of the servers will reflect the updates. Additionally, the fact that some servers may go offline while others come online must be considered.
  • This scaling challenge is faced by developers in many development environments, including developers using the popular Java development platform. The Java platform's goal in providing a platform independent environment is generally met by the fact that Java source code is compiled into an intermediate language called “bytecode,” which can reside on any hardware platform. In order to run the bytecode, it must be compiled into machine code via a Java Virtual Machine (JVM). A JVM is a platform-independent execution environment that converts Java byte code into machine language and executes it. The JVM provides the developer with the tools necessary for multi-threaded applications, including thread support, synchronization and garbage collection.
  • FIG. 1A illustrates a traditional implementation of a Java application running on a virtual machine under a given operating system on a processing system or server. As developers have attempted to scale Java applications to multiple processing systems, difficulties in maintaining object and primitive states across the systems become more numerous.
  • Traditionally, application developers themselves have been required to account for scaling using common forms of inter-server communication in order to share objects amongst distributed JVMs. One form of communication is Remote Method Invocation (RMI), which is a set of protocols that enables Java objects to communicate remotely with other Java objects. Another form of communication is the Java Message Service (JMS), which is an Application Program Interface (API) for accessing enterprise messaging systems. JMS supports both message queuing and publish-subscribe styles of messaging. Java Temporary Caching (JCache) is a distributed caching system for server-side Java applications.
  • While each of these techniques allow the developer the flexibility to add scaling to their application, the conventional techniques require application code modified, resulting in significant added complexity and development costs. Further, the conventional techniques limit scalability of the application tier, are often quite slow, and tend to abuse database infrastructure for transient needs. Finally, the task of maintaining object identity is a challenge as multiple instances of objects can be created at the different application servers.
  • An improved technology is needed for maintaining consistent data across virtual machines.
  • SUMMARY
  • The technology herein, roughly described, provides a technique for sharing data among multiple virtual machines in a cluster of virtual machines.
  • Data sharing functionality is provided to application software which was designed for use on a single virtual machine. In one aspect of the technology, distributed lock management is provided. Lock management is enabled by data sharing agents and a central manager. The data sharing agents include a lock manager, a transaction manager, an object manager, and a communication manager. A central manager, which may be provided on another server, interacts with application servers in a cluster to facilitate sharing so that object state is maintained consistently on all virtual machines. The central manager includes an object manager, a lock manager, transaction manager, communication manager, and a persistence manager.
  • In one approach, centralized lock management is provided where a cluster virtual machine requests a lock which affects managed object, and communicates a request to the central manager for the lock. The central manager determines whether the lock is available, and if it is, grants the lock to the virtual machine. The request from the virtual machine may include a global identifier of the managed object which allows the central manager to identify the object. The central manager grants the lock to the requesting virtual machine when no other virtual machine currently has the lock.
  • In another approach, the technology includes a computer-implemented method for controlling access to objects by different virtual machines. In this aspect, the method includes: communicating a request for a lock affecting a managed object at a first instance of an application running at a first virtual machine; receiving a message from a central manager indicating that the lock is granted, when the central manager determines that the lock is available; and repeatedly holding and releasing the lock until a command is received from the central manager to release the lock.
  • In another aspect, a computer-implemented method for controlling locks in a virtual machine cluster is provided. The method includes receiving from a first instance of an application running at a first virtual machine, a request for a lock affecting a managed object; responsive to the request, determining whether any other instance of the application running at any other virtual machine currently has the lock; and informing the first virtual machine of whether the lock is granted based on said determining step.
  • This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.
  • BRIEF DESCRIPTION OF THE DRAWINGS
  • FIG. 1A illustrates a conventional Java application environment.
  • FIG. 1B illustrates a logical depiction of a clustering server technology discussed herein.
  • FIG. 1C illustrates a system in which a central manager facilitates data sharing among a group or cluster of virtual machines.
  • FIG. 2 illustrates various layers of control within a virtual machine.
  • FIG. 3A illustrates a method for identifying and sharing managed objects among virtual machines.
  • FIG. 3B illustrates a method for defining transactions within the context of the technology
  • FIG. 3C illustrates transaction boundaries within a code segment.
  • FIG. 4 illustrates a representation of an object graph of managed objects.
  • FIG. 5 illustrates an example of managed objects, including classes and fields.
  • FIG. 6 illustrates a method for distributing object operations and data among virtual machines.
  • FIG. 7 illustrates the sharing of object data from a first virtual machine, in an initial update, using operation logs of the first virtual machine, and an operation log of a central manager.
  • FIG. 8 illustrates the sharing of object data from a first virtual machine, in an incremental update, using an operation log of the first virtual machine.
  • FIG. 9 illustrates a method for sharing of logical operations including field level object data and logical collections among virtual machines.
  • FIG. 10 illustrates a method for sharing object identity among virtual machines.
  • FIG. 11A illustrates a method for providing clustered locking.
  • FIGS. 11B-11D illustrate the signaling occurring in FIG. 11A.
  • FIG. 12A illustrates a method for providing greedy locking.
  • FIGS. 12B-12D illustrate the signaling occurring in FIG. 12A.
  • FIG. 12E is a state machine description of the method of FIG. 12A.
  • FIG. 13 illustrates a method for distributing thread signaling amongst virtual machines in a cluster.
  • DETAILED DESCRIPTION
  • The technology described herein includes a set of integrated components that provides a common virtual machine capability for application programs running on distributed systems each having its own local virtual machine. The components discussed herein allow transient data—data actually stored in memory in a virtual machine as part of in-memory object state—to be shared across various virtual machines. In a unique aspect, object state is shared through a series of shared operations, either logical or physical operations, which are detected and distributed as a series of transactions in order to replicate the current state of objects at any of the virtual machines throughout a cluster.
  • The technology will be described with respect to its application in conjunction with Java applications and Java Virtual Machines. However, it should be recognized that the inventive concepts have broader applicability to other virtual machine and development environments. Moreover, the managed objects utilized on various virtual machines need not be shared by the same application. Finally, as explained herein, respective virtual machines need not operate concurrently.
  • FIG. 1B is a block diagram depicting a logical representation of the technology discussed herein. FIG. 1B illustrates three processing systems each including an application 40, 50, 60 operating on a local virtual machine 42, 52, 62. The technology discussed herein provides a clustering server 75 which extends the capabilities of each virtual machine to all other processing devices in a given cluster. This includes sharing data amongst each of the virtual machines in a cluster on objects identified by a cluster administrator via a management interface. In this manner, the data sharing functionality can be easily added to application software which was designed for use on a single virtual machine.
  • This allows various features to be provided by the technology, include sharing of object state between virtual machines, flexible locking which is configurable at run-time, distributed method invocation and distributed wait-and-notify. Benefits include distribution of data among the virtual machines without the need to maintain state in a database, transparent recovery from application instance failures, clustering as an API-free infrastructure service, reduced development, testing, and maintenance costs, faster application development and scale-out, and fine-grained operations performance visibility and control. With the data sharing functionality provided, there is no API for the application developer to learn, apply, test, and maintain since the data sharing agents/libraries provide this transparency. Lower system life-cycle costs are another benefit, since organizations using the system need not spend time writing code in order to provide clustering capabilities. The system accomplishes this as an infrastructure software component that provides clustering as a service based on user-defined configuration settings which can be changed at production-time. This allows an application to adapt its reliability, availability and scalability characteristics to changing user demands without the need for new development.
  • In many cases, the data sharing functionality enhances performance. For instance, in one approach, when a shared object is updated, only the field-level changes are sent to the different virtual machines, and only those virtual machines with that object currently in memory are supplied with the update in real time. In another approach, the logical operations necessary to create a current object state are shared between virtual machines. These techniques significantly reduce the amount of data movement, and improve all-around performance of a fully clustered application. Moreover, the data sharing functionality provides this inter-virtual machine communication capability in a scalable manner that cannot be matched by peer-to-peer products.
  • FIG. 1C illustrates an exemplary implementation of the technology in a clustered system. In this implementation, a central manager 140 facilitates data sharing among a group or cluster of application servers 100. A group or cluster, shown generally at 100, includes a number of servers. This represents one embodiment of how applications are scaled to allow multiple servers to run respective instances of an application (111, 121, 131) for load balancing or to provide increased reliability, availability and scalability. In the present example, three servers are provided, namely server “A” 110, server “B” 120 and server “C” 130. The servers can be co-located or geographically distributed, and interconnected by any type of network, such as a LAN or WAN, or communication link (not illustrated).
  • As used herein each server or processing system includes, for example, one or more processors capable of executing instructions provided on readable media to perform the methods and tasks described herein. The processing system may include a volatile memory, a mass storage device or other non-volatile memory, a portable storage device, one or more communications or network interfaces and various I/O devices. The above described processing system hardware architecture is just one suitable example of a processing system suitable for implementing the present technology.
  • The servers 110, 120 and 130 each include a separate instance of an application, for example, application instance “A” 111, application instance “B” 121 and application instance “C” 131. Further, each server includes a virtual machine on which the application code executes, namely virtual machine “A” 112, virtual machine “B” 122 and virtual machine “C” 132. For example, each virtual machine may be a Java Virtual Machine (JVM) which executes byte code of an application. In one embodiment, the applications are the same application with different instances; in another embodiment, the applications call the same instances of the same classes of objects in their respective application code.
  • Each instance of the application runs locally on each application server and interacts with each virtual machine locally. Objects used by the application are created and maintained by the respective virtual machines on each server. In accordance with the invention, the application code for each of the applications need not provide for the clustering operations described herein. In essence, the application is prepared to run on a single virtual machine and extended to the cluster by the technology discussed herein. In this regard, a series of managed objects, which include a local instance of application object on each server, are identified and clustered by the technology.
  • A data sharing agent/library 113, 123 and 133 is provided on each respective server to provide functionality for sharing managed objects among the servers, as described in greater detail below. Files stored at the data sharing agent/library are loaded into the associated virtual machine upon start up to modify the application code when compiled into bytecode to provide the data sharing functionality. In particular, the data sharing agents 113, 123 and 133 are responsible for performing bytecode manipulation to implement clustered object management in each local virtual machine 112, 122 and 132. Each may include a lock manager that deals with gaining access to objects under locks, a transaction manager that creates a transaction log as described below, and an object manager. A communication manager may also be provided to enables the virtual machines to communicate with the central manager. The communication manager may inciude IP address and port information of the central manager.
  • Each server 110, 120, 130 may also include a conventional operating system and memory for storage of data, such as data used by threads of the application instances.
  • A central manager 140 is provided to facilitate data sharing among the virtual machines and, in particular, between the virtual machines on which the application instances run. The central manager 140 in conjunction with the data sharing agent/library 113, 123 and 133, acts as a “clustering server” for the applications 111, 121, 131. In essence, each application 111, 121, 131 sees one virtual machine, but with each application instance seeing changes to objects made by other application instances in the cluster. The central manager 140 includes a data sharing application 141 running in an operating system on the manager. The manager may be a separate physical server or may operate on a server with one of the virtual machines. The central manager 140 has the ability to communicate with each of the servers 110, 120 and 130 to share object state information.
  • The data sharing application 141 works in concert with the data sharing agent/libraries 113, 123 and 133 to distribute shared objects amongst the cluster systems 110, 120, 130. The data sharing application 141 can include a lock manager, transaction manager, communication manager, and a persistence manager. The persistence manager is able to persist object state information to a CM object representation store. The lock manager manages access to distributed locks between the various virtual machines. The transaction manager deals with moving data between members of the cluster in coherent terms. The object manager deals with keeping track of which virtual machines have what objects and what version of the object. A communication manager which enables the central manager to communicate with the virtual machines.
  • The object representation store 144 includes a record of the managed object states in accordance with the methods discussed herein. Because of the persistence of managed objects by the representation, each of the servers 110, 120,130 need not operate concurrently.
  • Advantageously, the central manager 140 and data sharing agent/libraries are implemented by a set of infrastructure software (which may be commonly distributed) that can be installed on suitable processing system hardware.
  • Subsequent to the installation of agents 113, 123 and 133, virtual machines 112, 122 and 132 are essentially clients of the central manager. As such, virtual machines may be referred to herein as clients. It should be understood that FIG. 1C illustrates only one possible implementation of the technology. For example, in FIG. 1C, the central manager 140 can be provided on a server that is separate from the servers hosting the applications or database software, or may be provided on one or more of the virtual machines. Although only one central manager is used in the present example, multiple managers on multiple servers can be clustered together to make a highly-available hub shared by many virtual machines, even across dispersed geographies. It is also possible to run multiple instances of an application at multiple virtual machines on one server.
  • A management console 150 provides a graphical user interface which allows an operator to configure and monitor the central manager 140. Optionally, the operator may define configuration files which are provided to the data sharing agent/library to specify which objects should be shared. This configuration data allows various managed objects to be included as managed objects or excluded as managed objects on each of the virtual machines in a cluster. In essence, this provides a form of drop-in/drop-out functionality for the managed objects. The management console can also be used to monitor: a) a current count of unique managed object instances for each client, on a per-class basis; b) a creation rate of managed objects, where both global and per-client counts are provided; c) a rate at which objects are flushed from the clients to the central manager, on a per client basis; d) a rate at which objects are requested from the central manager by a client, on a per client basis; e) a rate at which objects are written to a persistent object store by the central manager; f) a rate at which objects are requested from the persistent object store by the central manager; g) a view of all currently managed roots and fields; h) a list of locks with one or more pending lock or upgrade requests; i) a list of application process threads currently waiting due to contended locks; j) an on-demand display of locks which are currently part of process deadlocks; k) elapsed processing time and number of objects collected by the central manager garbage collection process; and l) a rate at which transactions are committed to the central manager, whether both global and per-client counts are provided.
  • FIG. 2 illustrates an application running within a virtual machine 210, and various mechanisms by which the data sharing agent/libraries interact with an application on a given virtual machine. A virtual machine 210 generally includes a number of class loaders 224. A bootstrap class loader 205 is provided by some implementations of virtual machines. In a Java Virtual Machine, each and every class is loaded by some instance of a class loader. Whenever a new JVM is started, the bootstrap class loader is responsible for loading key Java classes into memory first. The runtime classes are packaged inside of a runtime jar file. Normally, developers do not have access to details of the bootstrap class loader, since this is a native implementation. For the same reason, the behavior of the bootstrap class loader will also differ across JVMs. Other class loaders 224 may also be provided. These include, for example, the Java extension class loader, and the application class loader, responsible for loading all of the classes kept in the path corresponding to the java.class.path system property.
  • In one approach, application code at the server (110, 120, 130) is instrumented using files stored by the data sharing agent/libraries when the application code is loaded into the virtual machine. Where a bootstrap loader 205 is utilized, a custom “boot.jar” file may be used to replace the class definitions in the system dependent runtime .jar file. Where the virtual machine technology 210 does not implement a bootstrap class loader 205, this technique is not required. Other class loaders 224 are instrumented to allow the data sharing agent/library files to introduce the data sharing functionality into the application classes. Class loaders enable the virtual machine 210 on any respective server to load classes without knowing anything about the underlying file system semantics. Similarly, the class loader 224 allows the application 222 to dynamically load classes. The data sharing agent/libraries can inspect and, if activated, intercept API calls made by the application 222. The scope of interception can be at a byte code level in which case field updates, method calls, synchronization calls, and wait/notify calls, for instance, are visible and controllable at runtime. When alternative facilities, for example HotSwap or JVMTI, are provided by the virtual machine, the data sharing agent/libraries can introduce the data sharing functionality to application classes through these mechanisms. This technique allows the data sharing agent/libraries to delay and optimize the introduced data sharing functionality.
  • Note that the application source code remains unchanged, and in one implementation, no stored byte code is changed such that were one to decide not to run the clustering server, one can restart the application without enabling the byte code manipulation. As discussed more fully below, during this process, object classes specified as shared are identified and instrumentation added to allow server locking and logical change tracking.
  • Due to the instrumentation of bytecode at the virtual machine level, another aspect of “drop-in/drop-out” capability is provided. That is, the data sharing functionality which is provided by the instrumentation can be easily activated or deactivated by a system operator at application runtime. This drop-in/drop-out capability further allows the data sharing functionality to be provided for existing applications without modifying the application code to conform to an API, or providing any such API. The developer can write an application for a single virtual machine and configure the application to be transparently shared across multiple virtual machines. All that is required is the installation of the data sharing agent/libraries and the proper configuration of opt-in parameters via the management console. The drop-in/drop-out capability also allows rapid assessment of the degree to which the data sharing functionality can benefit a given application, what-if analysis of various opt-in sets, and the ability to switch the data sharing functionality on and off at runtime. The drop-in/drop-out capability also eliminates the need to use custom-developed or vendor framework clustering and memory sharing in new applications since these needs can be handled with no need for explicit code.
  • This data sharing functionality may alternatively be implemented in the bytecode interpreter natively. That is, while developers normally do not have access to the bytedcode interpreter, virtual machine providers who do have access to the bytecode interpreter may build the same functionality provided by instrumentation of the bytecode at the classloader level directly into the virtual machine instead.
  • FIG. 3A illustrates a general method for identifying and sharing managed objects among virtual machines. At block 300, an application begins its execution and at step 302 the application byte code is instrumented prior to execution of any functions on objects, as described above. At block 305, the instrumentation identifies objects of the application for which state information is to be shared. In particular, these objects are identified as root objects of an object graph (see also FIG. 4). These objects are identified based on an operator defined configuration identifying which objects should be managed objects in the cluster.
  • In this step, the byte code instrumentation adds functionality to each managed class transparently. Exemplary pseudocode representations of this functionality include a function lockmanager.getlock( ), a transactionmanager.starttransaction( ) and a transactionmanager.commitTransaction( ) and lockmanager.releaseLock( ). As will be explained below, the getlock and releaseLock functions request, respectively, a lock from the central manager for the cluster-wide managed object via the lock manager process, and a lock release on the managed object from the central manager. The transactionmanager.starttransaction and transactionmanager.commitTransaction functions are used to generate transactions which communicate changes to the central manager. These functions surround the application code, as described below.
  • At block 310, an object graph of each of the identified root objects is navigated to identify the objects that can be reached from the root object. For example, an object is reachable by the root object if there is a field assignment of an object reference into one of the root's field values at runtime. At block 315, the objects in the object graph are identified as managed objects, such as by flagging the objects. Thus, the root object and the objects reachable from the root object become managed objects. Optionally, the operator can use the management console to selectively exclude objects which are reachable from a root object from being managed by declaring a field to be transient.
  • In one aspect, the manager allows specification of root objects to manage all objects accessible by the root. An object is reachable by the root object if it is part of the object's reference graph, such as, for example, where there is a field assignment of an object reference into one of the root's field values at runtime.
  • FIG. 4 illustrates a representation of an object graph of managed objects. The object graph 400 includes a root object and a number of objects, shown as circles, which are reachable from the root object, as indicated by the connecting arrows. An object pointed to by another object is reachable from that object. A specific illustration is provided below in connection with FIG. 5.
  • An object graph includes a root object and objects that are reachable from the root object. A root object can be a long-lived object, such as a cache implemented using native Java collections, a servlet session, or a hash map, an example of which is provided by the Java class HashMap. For example, the operator can configure managed objects using a configuration file in a known format, such as XML, or alternatively use the management console to identify the managed objects. Moreover, note that not all objects in an application need be managed. Only a subset of all objects used by an application need to be identified as managed. A managed object is a distributed object whose state is maintained consistently at the different virtual machines in a cluster of virtual machines. Generally, it is desirable to manage objects that represent pure state information, while avoiding replicating objects that refer to operating system resources. For example, business objects such as customer records might make good managed objects.
  • For example, an XML configuration file at the data sharing agents/libraries may modify values of a “<root>” element. The operator specifies the fully qualified field, and a name to associate with the field. To illustrate, the following configuration sets up two objects for sharing—“exampleField1” and “exampleField2”, which are members of the “ExampleClass1” and “MyClass2” classes, respectively:
    <roots>
     <root>
      <field-name>ExampleClass1.exampleField1</field-name>
      <root-name>exampleRoot1</root-name>
     </root>
     <root>
      <field-name>MyClass2.exampleField2</field-name>
      <root-name>exampleRoot2</root-name>
     </root>
    </roots>
  • Alternatively, roots can be given a common “name” even though they may be two differing fully qualified field names. In this case, the two or more root fields that share the common name will refer to the same object instance. Hence, one can, in two different classes, bind the same root to different variables. In terms of the example, even though there are two different fields in different classes, even though they are different fields, if they share a common name, they will be the same set of objects.
  • The object manager in the client can dynamically prune in-memory versions of a managed object graph so that only portions of the managed graph need be stored in the client virtual machine's memory at a time. This allows arbitrarily large shared object graphs to be fit into a constrained memory footprint in the client virtual machines. Pruned segments of the object graph can be faulted in from the server dynamically as needed as code on a virtual machine traverses the managed graph and follows a reference to an object that has been pruned. This process happens automatically and transparently to the user code. As this happens, the permanent representation of the managed object graph is unaltered in the central manager.
  • Returning to FIG. 3A, at block 320, the instrumented application begins running and, at block 325, the instrumentation detects operations, such as method calls and field set operations, at a given virtual machine on which the instrumented application is running, that affect the states of the managed objects. The process of detection at step 325 is further detailed with respect to FIGS. 3B and 3C.
  • At block 330, information identifying the operations, such as the method calls and field set operations, and the central manager level (or global) unique identifier of the object or objects involved, is communicated from the virtual machine to the central manager and, at block 335, the central manager uses the information to update a representation of the managed objects' states locally and at other virtual machines.
  • The central manager may assign global identifiers to the managed objects so that it can recognize any managed object in the cluster. Conventionally, only locally specific, non-deterministic identifiers are assigned to objects by the virtual machines. In accordance with the technology herein, when a new managed object is created on a local virtual machine, a global unique identifier is assigned to the object by the virtual machine on which the object is created. A group of central manager level unique identifiers is provided by the central manager to each virtual machine.
  • Updates to the fields of a managed object are tracked at a fine grained level of granularity and pushed to other virtual machines via the central manager. By joining a root graph, an object is flagged as managed and its state is kept up-to-date across a cluster of servers.
  • FIG. 3B illustrates a method for sharing the transaction data involving object data among virtual machines. At block 345, optionally, a determination is first made as to whether a given method is synchronized or a named lock is identified for the method, and at step 350, whether the lock has been acquired. Acquiring a lock is optional depending on how an operator chooses to configure it. Transactions can be created under concurrent locks in which case no locks are acquired. This may be used in the case where potential write-write conflicts are tolerable. At step 355, the application begins operation on the locked code. At block 360, a transaction log starts recording operations which are performed by the thread which affect the states of managed objects at a first boundary in the code. At block 365, the transaction records all operations until block 370, at which point the transaction is concluded when the thread crosses a second transaction boundary. At block 375 the transaction is stored until forwarded to the central manager. At step 380 the lock (if any) is released.
  • In one case, transactions can be provided on both method and Java synchronization boundaries, where a transaction is a set of changes to managed objects made between defined transaction boundaries. Transactions are associated with, and protected by, zero or more locks. Transactions and locks function as a multi-virtual machine extension of standard Java synchronization and the Java memory model. Java synchronization provides exclusive thread access to sections of code on monitor/lock enter, and flushes local changes to main memory on monitor exit. In a cluster, locks provide a user-defined, cluster-wide access policy to sections of code, and local changes are flushed to the central manager at the close of a transaction. In this way, threads in a cluster of multiple virtual machines can interact in the same way that they do in a single virtual machine.
  • This is illustrated by FIG. 3C where the transaction boundaries need not be the same as the lock boundaries. For a synchronized block of code that is synchchronized on managed object A, a first lock is required and a first transaction boundary (startTransaction(P)) begins after acquisition of the first lock. Where a nested synchronized block of code that is synchronized on managed object B (synchronized(B)) exists, the transaction boundary for the first transaction P is completed and a second transaction started for the nested synchronized block of code. The transaction boundaries in this context are synthesized by the instrumentation of the byte code (or within a suitably enabled virtual machine) to provide transaction boundaries which are granular to the particular functions enumerated in the application code. Each transaction is thus defined (in the Java context) in terms of a thread monitor enter and monitor exit in a code block. For named locks, the transaction is defined in terms of a method boundary.
  • FIG. 5 illustrates an example of managed objects, including classes and fields. The managed objects include a root object 510 “users” and a number of objects which are reachable from the root object, including an object 520 named “myCache”, an object 530 named “User”, and an object 540 named “Address”. The object 530 has the fields “Name”, “Age” and “Address”. The object 540 named “Address” is reachable from the “Address” field of the object 530, and includes fields “Street”, “State” and “Zipcode”. The objects provided could be used by a web-based application, for instance, which requires a user to provide his or her name, age and address. Note that there is nothing special about the root object 510 or object 520; any object can be identified as a managed object, (except objects that represent JVM-specific or host machine specific resources, such as network sockets or file descriptors).
  • In this example, a users object references a map called mycache. Once one establishes a reference that the cache is managed, then the entire sub-graph of an object is managed. That is if mycache is managed, as a root, everything it points to is also managed Note that Java primitives may also be assigned object IDs also. Once a managed object has a reference to an unmanaged object, it makes everything that it references become managed.
  • FIG. 6 illustrates a method for sharing object information among virtual machines using operation logs. In a unique aspect of the technology, object data can be shared logically and physically, depending on the operation on the object by an application. By sharing data using operations on any individual local object, each virtual machine maintains a locally specific representation of object state. To do this, the steps which were taken by a virtual machine to get its memory to store object data are detected and logged, and those steps are then performed at another virtual machine. For example, consider that each virtual machine typically assigns a locally generated identifier for each instantiated object. When information associated with the object, such as field level data is stored, the object identifier, as a key, is hashed to determine a location (bucket) in a hash map in which the information will be stored. However, since each virtual machine uses a different local identifier for its local instance of the same object, each virtual machine's hash map will differ even though each hash map represents the same object state. Thus, physically copying the hash map data in one virtual machine's memory, bit by bit, to the memory of another virtual machine, would not successfully copy the underlying object state information. A specific technique for achieving logical sharing overcomes this problem, as follows.
  • As noted above in FIG. 3A, when application operations occur at step 320 accessing or affecting a managed object, those operations are detected at step 325 and communicated to the central manager at step 330. The virtual machine (in this example VM1) is responsible for updating and maintaining its own local representation of object state at step 610. VM1 maintains a local representation of the states of the objects which are instantiated by the application, including managed and non-managed objects. This is a base function of the virtual machine.
  • Step 325 is performed by recording, for example, the method calls or field set operations that the application code has performed. Instead of keeping track of the actual object references, the transaction log keeps track of the actions the application has done. Every time a central manager need to create the object in a new VM or to make changes to it, it can replay this log. For each action, such as when a new object is created or a function (such as a put call) is performed, this logical action is recorded and the physical steps written into a transaction. Any new objects and their data is now recorded in the log.
  • These transactions are stored in one format in the memory in the virtual machine, then transmitted to the central manager (in, for example, a serialized format) in the message in the communications layer and deserialized at the central manager.
  • At step 330, VM1 updates the central manager. The updating may occur from time to time at various points in the execution of the application code. For example, the updating may occur after the application updates one or more managed objects under a lock, as discussed above. As noted briefly above, the instrumentation added to the application code may include a transactionmanager.committransaction( ) which takes the log built up in the transaction through this whole process, and communicates it to the central manager. The shipping may occur immediately or in a grouped set of transactions, such as in a batch job.
  • To perform the update, VM1 communicates a log, VMLog, to the central manager. VM1 may delete the log and start a new log when the central manager confirms receipt of the log. Any type of network communication technique may be used. As mentioned, the data sharing agent/library at each virtual machine may include functionality for communicating with the central manager.
  • At block 630, the central manager processes the transactions stored in the VMLog to update a local representation of the states of the managed objects. Essentially, the operations such as method calls, with associated field values, which were performed at VM1, are stored in a data structure on the central manager.
  • A description of each object is provided on the central manager. This description includes meta data defining the object's class, its fields and the field values. For a physical object, for example a class “myclass” with four fields, the server description includes the server class and IDs for each field. For example, a physical object includes the name of the class, the name of the class loader, fieldname, field value pairs for literal fields, field name and referenced object ID pairs for reference fields, object version, and possibly other information. For logically managed objects, one needs to know what to do with changes which may have occurred. A description of a logically managed object in includes, for example, where the logically managed object is a map, the contents of which may be a set of keys, collection of values, or set of key-value mappings. The order of a map is defined as the order in which the iterators on the map's collection views return their elements. For this example of a logically managed object, a representation of the map is kept on the central manager. The representation relates the object ID or literal keys to the corresponding object ID or literal values. In addition, a logical action (such as a put) is assigned a function ID which is interpreted by the central manager allowing the central manger to create the appropriate mapping of keys to values. In the case of other logically-managed classes, such as a list, examples of logical actions are add and remove; for a map, actions includes puts and gets; any number of logically managed actions may be stored in this manner. The central manager's representation is not another instance of each managed object, but merely a representation of that object.
  • Each logical action performed on a logically managed object is identified and the data associated with the logical action provided to the central manager to update its representation. These logical actions are passed to any other virtual machine in the cluster that currently has said logically-managed object in its memory so they may be replayed against its local instance of said managed object.
  • At block 635, the central manager updates the other virtual machines in the cluster so that the state of the managed objects at VM1 is replicated at the other virtual machines. As noted above, depending on whether the update is of a physically managed object or a logically managed object, the transaction may have a slightly different format. In addition, there are two different scenarios for an update depending on whether or not the update to the other virtual machines is an initial update (decision block 640).
  • An initial update occurs when the central manager first updates a virtual machine, in which case it is necessary to convey the current state of the managed objects to the virtual machine. This may occur after application startup or after a new virtual machine joins the cluster. In one approach, the central manager can store each of the logs received from VM1 (or any of a number of VMs) and provide them to the other virtual machines to be played. However, this approach is inefficient as many operations may change the same managed objects repeatedly. Since only the most current state of a managed object is relevant, and not the previous states it traversed to reach the current state, it is more efficient for the central manager to generate a log of operations (central manager log) from its representation of object state (block 645). This approach is more efficient since only the operations which are necessary to reach the current object state are generated. At block 650, the central manager communicates the central manager log to the other virtual machines and, at block 655, the virtual machines play the central manager log to update their local representations of object state. The operations in the central manager log, such as method calls and field set operations with associated values, are performed at the other virtual machines so that the state of the managed objects at the central manager, and at VM1, is replicated at the other virtual machines. An object graph at the other virtual machines is thereby updated so that it is a replica of the object graph at the central manager and at VM1.
  • If an initial update of a virtual machine has already been performed, then the subsequent updates can be incremental updates. In this case, the central manager conveys the virtual machine log from VM1 to the other virtual machines (block 660), and the other virtual machines play the virtual machine log to update their local representations of object state (block 665). Again, the object graphs at the other virtual machines are thereby updated so that they are a replica of the object graph at the central manager and at VM1. The updating of the other virtual machines by the central manager may occur from time to time. For example, the central manager may update the other virtual machines when it receives an update from VM1.
  • Note that the process shown in FIG. 6 is performed at each of the virtual machines in a given cluster, independent of the processes on other servers. Thus, the central manager receives logs from the different virtual machines and communicates the virtual machine logs, or logs generated by the central manager, to the appropriate virtual machines to maintain a consistent representation of the states of the managed objects across all of the virtual machines. Furthermore, by maintaining current state information locally, the central manager can update new virtual machines which are added to a cluster, and virtual machines which come back online after being taken offline, such as for maintenance.
  • Initial and incremental updates are illustrated further, as follows, in FIG. 7 and FIG. 8, respectively.
  • FIG. 7 illustrates the sharing of object data from a first virtual machine, in an initial update, using operation logs of the first virtual machine, and an operation log of a central manager. Here, a virtual machine “A” 710 sends a number of virtual machine logs to the central manager 740 over time, as indicated by paths 712. When an initial update of one or more of the other virtual machines is needed, the central manager generates its own log of operations, central manager log, and sends it to the other virtual machines, such as virtual machine “B” 720 and virtual machine “C” 730 via paths 722 and 732, respectively. Thus, one central manager log can represent the changes to object state which result from multiple virtual machine logs.
  • FIG. 8 illustrates the sharing of object data from a first virtual machine, in an incremental update, using an operation log of the first virtual machine. Here, a virtual machine log sent from virtual machine “A” 810 to the central manager 840 via path 812 is relayed to the other virtual machines, namely virtual machine 820 and virtual machine 830, via paths 822 and 832, respectively. That is, the central manager provides a communication to virtual machine 820 and virtual machine 830 which includes the information from the virtual machine log provided by virtual machine 810. In an alternative, peer-to-peer embodiment of the technology, the virtual machine log from virtual machine 810 could be sent directly by virtual machine 810 to the other virtual machines 820 and 830 rather than being relayed by the central manager.
  • FIG. 9 illustrates a method for sharing of field level object data and logical operations among virtual machines. As noted above, field level sharing of object data as well as sharing logical operations are unique aspects of the technology.
  • By sharing object data at a field level of granularity, it is possible to share changes to object state at a fine grained level. That is, changes to specific fields of managed objects can be shared among virtual machines without sending unnecessary information regarding fields of managed objects which have not changed, or fields of unmanaged objects. This approach minimizes the amount of information which needs to be communicated between the central manager and the virtual machines. For example, referring to the “Address” object 540 in FIG. 5, assume the “Street” field is updated to a value of “123 Main Street”. In this case, it would only be necessary to provide updated values, in order for the central manager and the other virtual machines to update their representations of object state. There is no need to share the other fields of “Address”, such as “State” and “Zipcode”, which did not change. Nor is there a need to share the states of objects from which object 540 can be reached, such as objects 510, 520 and 513, which also did not change. An example process for sharing of field level data among virtual machines follows.
  • When an operation on a managed object occurs in the application (as in step 320 previously described), transactions are created at step 902 in accordance with the foregoing description of steps 1315, 1320 and 1325. The information transmitted will depend on whether the object is a physically managed object or a logically managed object (step 904). If the object is a physically managed object, at block 915, field level changes to the managed objects are provided in the transaction. That is, the changes are detected at a field level of granularity. This may include, e.g., detecting field level data affected by an application function. At block 920, a central manager uses the field level data to update its local representation of object state. The information provided at step 915 may include for a physical object, the name of the class, the name of the class loader, fieldname and field value pairs for literal fields, field name and referenced object ID pairs for reference fields, object version, and possibly other information, as discussed above.
  • At block 925, to perform an update of any other VM, the central manager communicates the field level data to the other virtual machines in the cluster and, at block 930, the other virtual machines use field level data to update respective local instances of the managed objects.
  • Similarly, if the transactions affect logically managed objects, the transactions include logical operations at step 935. At block 940, a central manager uses the method calls and other logical operations to update its local representation of object state. At block 945, to perform an update of any other VM, the central manager communicates the logical operations to the other virtual machines in the cluster and, at block 950, the other virtual machines replay those logical operations against their respective instances of the managed objects to update the state of those managed objects.
  • FIG. 10 illustrates a method for sharing object data among virtual machines while maintaining object identity. In a unique aspect of the technology, where conventionally objects would be distributed by maintaining additional copies of objects in, for example, a clustered Map, the sharing technology maintains the unique identity of managed objects by eliminating the need to copy manage objects themselves.
  • As noted above, when application operations occur at step 320 accessing or affecting a managed object, those operations are detected at step 325. Each virtual machine (in this example VM1) is responsible for updating and maintaining its own local representation of object state at step 610. VM1 maintains a local representation of the states of the objects which are instantiated by the application, including managed and non-managed objects. The VM updates any change to a local instance of a managed object at step 1015.
  • Step 325 is performed by recording, for example, the method calls or field set operations that the application code has performed. Instead of keeping track of the actual object references, the transaction log keeps track of the actions the application has done. For each action, at block 1025, data identifying the operations of a changed object is included with the transaction. That is, for each transaction, an object ID is generated at the client and, as noted above, is provided as part of the field data for a physically managed object, as well as the operations data for a logically managed object. Object references are thus maintained in the local representation at the central manger and at any other VM using the CM log to update its local representation of the object. At block 1030, the central manager is updated. To perform the update, VM1 communicates data identifying the object and the logical operations to the central manager. At block 1035, the central manager updates its local representation of managed objects using the object ID and transaction ID data. At block 1040, the central manager communicates data identifying the operations to the other virtual machines and, at block 1045, the other virtual machines update existing instances of the changed objects without creating new instances of the objects. With this approach, object identity is maintained across the virtual machines.
  • The central manager also provides various cluster wide locking functionality. In one embodiment, both named manual locks (named locks) and automatic locks (auto locks) are provided. Clustered locks can span an arbitrary number of VMs. For automatic locking, the CM globally locks any point where the application code uses, for example, the Java “synchronized” keyword, to provide distributed locking for applications where “synchronized” is already in use or where the application is multi-thread safe. Named locks can be used with help from developers for applications that were never designed to be distributed and multi-threaded. Named locks specify which blocks of code in any application should be locked globally.
  • Both auto locks and named locks are available in two different modes, clustered locks and greedy locks. With clustered locks, the virtual machine obtains a lock explicitly from the central manager each time a lock is needed.
  • FIGS. 11A-11D illustrate clustered locking.
  • At block 320 the application in the course of performing operations will request a lock on a managed object A virtual machine may request a lock when it encounters a block of code which uses the Java key word “synchronized”, as mentioned previously. Alternatively, the operator may use the management console to designate a block of code of an application which does not use the keyword “synchronized” as a method which invokes a request for the lock.
  • In one embodiment, both named manual locks and automatic locks, are implemented. Administrators can use automatic locks, which globally lock any point where the application code uses, for example, the Java “synchronized” keyword, to provide distributed locking for applications where “synchronized” is already in use or where the application is multi-thread safe. Named locks can be used with help from developers for applications that were never designed to be distributed and multi-threaded. With named locks, users can specify which blocks of code in an application should be locked globally.
  • At block 1115, VM1 sends a request for a lock to the central manager. At block 1120, the central manager accesses its records to determine if the lock on the object is currently available. For example, the central manager may maintain a record listing object identifiers and associated lock status, indicating whether there is a lock on an object and, if there is a lock, which thread in which virtual machine has the lock, and the type of lock, e.g., read, write or concurrent. A read lock allows all instances of the application on the different virtual machines to have concurrent read access but not write access to managed objects within the scope of the given lock. A write lock allows one thread on one virtual machine to have read and write access to managed objects within the scope of the given lock, but prevents any other thread in any other virtual machine from acquiring the given lock. A concurrent lock allows multiple threads on multiple virtual machines to make changes to managed objects at the same time. This lock maintains a stable view within the transaction that the lock protects but allows write-write conflicts between threads in the same or other virtual machines. Concurrent locks should be used when performance is more important then the possibility of write-write conflicts. In the case of a write-write conflict, the last writer wins.
  • At decision block 1125, if the lock is not available, the central manager waits until the lock becomes available. When the lock is available, the central manager grants the lock to the requesting virtual machine, at block 1135, and updates its records accordingly. If applicable, at block 1140, the central manager blocks any other thread in the same or other virtual machines from taking control of the lock. At block 1145, the virtual machine may perform any operation under the lock locally without CM interaction.
  • After using the lock, the virtual machine informs the central manager that it is releasing it, at block 1150. At block 1155, the central manager updates its records accordingly, and grants the lock to the next thread in contention for that lock in any connected virtual machine, if any. That is, the lock is granted to any other thread in any virtual machine that is blocked in contention for the lock.
  • In another alternative, the lock is a “greedy” lock, in which case the virtual machine holds the lock so that threads local to that virtual machine may acquire and release the lock repeatedly (at step 1145) without communicating with the central manager until the central manager commands it to release the lock. With a greedy lock, VM1 holds the lock not only for the duration of one synchronized block, but until the lock is recalled by the central manager, such as if another virtual machine requests the lock from the central manager.
  • FIGS. 12A-12D illustrate the operation of a greedy lock. Recall with a clustered lock that VM1 releases the lock after a specified duration of work, one and only one block of code protected by that lock. With a greedy lock, VM1 may continue to process as many blocks of code protected by that lock as it needs, in a local lock context, until the lock is recalled by the central manager, such as if another virtual machine requests the lock from the central manager.
  • FIG. 12A is equivalent to FIG. 11A up to step 1135. FIG. 12A may be read in conjunction with illustrations in FIGS. 12B-12D. Once a greedy lock is granted to VM1, at step 1240, VM1 holds the lock and may access and release the lock locally without CM interaction. At step 1245, the CM receives a request for the lock from another VM. At step 1250, the central manager will request that VM1 release the lock and when VM1 releases the lock at step 1255, the CM updates its records accordingly at step 1260 and grants the lock to the requesting VM.
  • FIG. 12E shows a greedy lock state machine. This diagram uses two VMs as a simplification. The state may be initialized at the Lock Requested state in VM1. The sole exit transition is to the lock state maintained in the central manager. Two transitions can exit this state, No Others In Contention, meaning no other virtual machines are in contention for the lock, or Others in Contention, meaning other virtual machines are in contention for the lock. If the No Others In Contention state is true, the VM will transition to the Lock Entered state, transition to the Lock Complete state, and back to the Lock Requested state. From here the transitions and states remain the same for VM1, in a loop, until such point where another VM requests the lock and the Others In Contention transition is followed out of the Lock Requested state to the Blocked state on the central manager. At this point the Central Manager blocks the VM1 from moving to another Lock Entered state and instead hands the Greedy Lock to the VM2. VM1, which then can enter its own series of Lock Requested—check Lock—Lock Entered—Lock Complete state transitions until another VM requests the greedy lock.
  • The following pseudo-code provides a further illustration of the concepts described herein. Assume the following pseudo-code represents application code which has been instrumented in accordance with the discussion of step 305. In this example, a new thread is adding a new object and the agent will traverse the graph of the person object and make all the objects it refers to managed and give them all object IDs. A record of these new objects is placed into the transaction log which will be forwarded to the central manager. Note that each VM gets a batch of central manager level object IDs ahead of time so that it can assign them to the objects. For example, each VM may get any number of new object IDs that it can assign locally at will. If it runs out of object IDs, it can request additional IDs from the central manager. Also note that the VM's internal object ID does not affect the central manager or the central manager level Object ID. The code below may be operated on by a thread on any virtual machine.
    Class Cache {
    /* Define the object “cache” */
     Map myCache=new HashMap( )
      /*Define the object “myCache” as a empty HashMap*/
       public void put(String name, User user) {
        /* Call the “put” method */
       synchronized(myCache) {
       /* Request lock on myCache at virtual machine */
        lockManager.getLock(myCache)
         /* Request lock on myCache from central
        manager (this code is added by instrumentation) */
        transactionManager.startTransaction( )
         /* Start a transaction at the virtual machine
        (this code is added by instrumentation) */
        myCache.put(name, user)
         /* Call the put method for “myCache” */
        transactionManager.commitTransaction ( )
         /* Commits the transaction log to the central
         manager (this code is added by
         instrumentation )*/
        lockManager.releaseLock(myCache)
         /* Release the lock on myCache at virtual
        machine (this code is added by instrumentation) */
       }
      }
     }
  • First, assume that at VM1 there are two threads active both asking for a lock on the object “myCache”. In this example, the object myCache has been identified as a managed object. A first thread will be granted the lock by virtual machine VM1. Next, the data sharing agent indicates to the central manager that there is a thread on VM1 that has requested a lock on myCache. The agent requests a lock from the server. If no other virtual machine has the lock, the central manager will grant the lock to the VM.
  • At this point, the application code at VM1 is able to move on. In the virtual machine, the agent starts a transaction for this thread. The agent will now keep track of logical actions and field changes to managed objects performed by thread one. This occurs whenever a thread obtains a lock on a managed object.
  • Once this first thread has received a lock and started its transaction, now it is able to execute the operations in the protected block of code as originally defined by the application code. Suppose, for example, a second VM with another thread trying to execute the same block of code protected by the same lock on a different virtual machine. There are now two threads locally that are synchronized by VM1, and a third thread on VM2 trying to access the same object. The native lock manager of VM2 will allow this lock, but when the function “getLock” is performed on VM2, the central manager will not grant VM2 the lock because it is already held by thread one in VM1.
  • Threads two and three are blocked trying to get a lock. Thread two is on the same VM as thread one, so it is blocked trying to get the VM1 object monitor from the native lock manager of VM1. Thread three has been given the local monitor on VM2 but is blocked trying to get the clustered lock from the central manager.
  • The application code can then perform the put operation (in this example) on the object once the lock is granted. Once this is completed, the transactionmanager.committransaction( ) takes the log built up in the transaction and ships it to the central manager. Next, since thread one is finished with the lock, the lockManager.releaseLock(myCache) releases the clustered lock. Thread one exits the protected block of code and has now completed its work.
  • Once thread one in VM1 has released the local lock, the native lock manager in VM1 allows thread two to obtain the local lock. If the central manager grants thread two the clustered lock, thread two executes the same block of code against another user object. While that is happening, thread three at VM2 is still blocked in contention for the clustered lock from the server, even though it has been granted the local lock by the native lock manager in VM2. Thread three remains blocked until thread two completes its execution of the protected block of code and releases the lock. At such time, the central manager awards the clustered lock to thread three in VM2. Because thread three is in a separate VM than threads one and two, the transactions created by threads one and two must be applied, in order, at VM2 to bring the changed managed objects up to date before thread three is allowed to execute the protected block of code. Once the transactions created by VM1 under the scope of the clustered lock have been applied in VM2, thread three is allowed to execute the protected block of code. When thread three has completed the protected block of code, the transaction it created is committed and the clustered lock is released by thread three. The clustered lock returns to its uncontended state.
  • FIG. 13 illustrates a method for signaling between threads in separate virtual machines by extending thread signaling mechanisms built into the virtual machine to have a clustered meaning. In a unique aspect of the technology, thread signaling, such as object.wait( ) and object.notify( ) and thread.join( ) methods in the Java Virtual Machine, is extended to apply to all threads in all virtual machines in the cluster. As mentioned previously, synchronization of multiple threads on a single virtual machine is conventionally achieved using locks that allow only one of the threads in that virtual machine to execute a protected block of code at a time. As mentioned previously, this conventional locking is extended to have a clustered meaning. In addition, a technique is required for signaling waiting threads which may be distributed across different virtual machines.
  • For example, if a thread currently holds the lock on an object, it may call “object.wait( )” which causes the calling thread to release that object's lock and pause execution. Another thread may then acquire the lock on that object. It may then call the Java method “object.notify( )” which will notify a single thread waiting on that object. It may also call the Java method “object.notifyAll( )” which will notify all threads waiting on that object. Waiting threads that are notified in this way resume execution and go back into active contention for that object's lock. While this is satisfactory in a single-virtual machine environment, a technique is needed for signaling threads on different virtual machines to coordinate the pausing and resuming of thread execution. A technique is needed for extending existing thread signaling mechanisms such as Java's “object.wait( )” and “object.notify( )” methods to apply to all threads in all virtual machines in the cluster as they do to threads in the same virtual machine. See, for example, http://java.sun.com/docs/books/jls/third_edition/html/memory.html#17.8 An example of such a technique follows.
  • In a unique aspect of the technology, the native thread signaling utilities of a virtual machine are extended to the cluster. These can include, in a Java context, synchronization (grabbing the lock in the first place), wait and notify, the Thread.join( ) method, and the like. In other virtual machine contexts, other thread signaling technologies may be extended.
  • In FIG. 13, this feature of the technology is described with respect to the object.wait( ) and object.notify( ) utilities, but the technology is not limited to these signaling utilities. At block 1300, instrumented application byte code running in a thread at a first virtual machine implements a synchronized call on managed object. After performing one or more operations defined in the application code, an object.wait( ) call is encountered in the code at step 1305. The thread will now release the lock it has on that object, pause execution and await notification at step 1320. Another thread may then acquire that object's lock. This thread may be on the same virtual machine as that of steps 1300 or, in accordance with the technology, a different virtual machine. At step 1315, the second thread calls object.notify( ) and, assuming that the thread is executing on a different virtual machine, the notify signal is passed to the central manager at step 1318. At step 1325, the central manager distributes the notify signal to a waiting threads or all waiting threads.
  • Once the notification is sent, step 1320 is true and the first thread will then request access to a lock at step 1330. Any other threads which were waiting on the notification will likewise resume execution and request access to the lock at step 1335. At step 1340, the central manager will perform lock management in accordance with the foregoing discussions.
  • Note that while example implementations are discussed in which virtual machines run on servers, which is a suitable approach for storing large amounts of data for a web-based application for instance, any type of computing device may be used, including personal computers, minicomputers, mainframes, handheld computing devices, mobile computing devices, and so forth. Typically, these computing devices will include one or more processors in communication with one or more processor readable storage devices, communication interfaces, peripheral devices, and so forth. Examples of storage devices include RAM, ROM, hard disk drives, floppy disk drives, CD ROMS, DVDs, flash memory, and so forth. Examples of peripherals include printers, monitors, keyboards, pointing devices, and so forth. Examples of communication interfaces include network cards, modems, wireless transmitters/receivers, and so forth. In some embodiments, all or part of the functionality is implemented in software, including firmware and/or micro code, that is stored on one or more processor readable storage devices and is used to program one or more processors to achieve the functionality described herein.
  • The foregoing detailed description of the technology herein has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the technology to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. The described embodiments were chosen in order to best explain the principles of the technology and its practical application to thereby enable others skilled in the art to best utilize the technology in various embodiments and with various modifications as are suited to the particular use contemplated.
  • Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims (25)

1. A computer-implemented method for controlling access to objects by different virtual machines in a cluster, comprising:
detecting when a first instance of an application running at a first virtual machine requests a lock affecting managed object;
responsive to the detecting, communicating a request to a central manager for the lock, the central manager determining whether the lock is available; and
receiving an indication from the central manager that the lock is granted when the central manager determines that the lock is available.
2. The computer-implemented method of claim 1, wherein the method further includes the step of:
informing the central manager that the first instance of the application is releasing the lock.
3. The computer-implemented method of claim 1, further comprising:
associating an identifier with the managed object which is unique across at least the first virtual machine and any other virtual machine in the cluster and wherein the request includes the identifier.
4. The computer-implemented method of claim 3, wherein:
the central manager uses the identifier in the determining of whether the lock is available.
5. The computer-implemented method of claim 1, wherein:
the detecting, communicating and receiving steps are performed at the first virtual machine.
6. The computer-implemented method of claim 1, wherein the method further includes:
receiving the indication from the central manager when no other instance of the application running at another virtual machine which is managed by the central manager currently has a lock on the managed object.
7. The computer-implemented method of claim 1, wherein:
the first instance of the application requests the lock when it enters a synchronization block of code.
8. The computer-implemented method of claim 1, wherein:
the first instance of the application releases the lock when it exits a synchronized block of code and communicates the lock release to the central manager.
9. The computer-implemented method of claim 1, wherein:
the lock comprises a write lock which allows the first instance of the application to have write access to the managed object but prevents any other instance of the application running at any other virtual machine that is managed by the central manager from having write access to the managed object.
10. The computer-implemented method of claim 1, wherein:
the lock comprises a concurrent lock which allows multiple virtual machines to make changes to managed objects at the same time.
11. A computer-implemented method for controlling access to objects by different virtual machines, comprising:
communicating a request for a lock affecting a managed object at a first instance of an application running at a first virtual machine;
receiving a message from a central manager indicating that the lock is granted, when the central manager determines that the lock is available; and
repeatedly holding and releasing the lock until a command is received from the central manager to release the lock.
12. The computer-implemented method of claim 11, wherein:
the communicating and receiving are performed at the first virtual machine.
13. The computer-implemented method of claim 11, wherein:
the step of communicating occurs when first instance of the application accesses a synchronized method.
14. The computer-implemented method of claim 11, wherein the step of communicating occurs when the application accesses a named lock.
15. The computer-implemented method of claim 11 wherein:
the central manager provides the command to the first instance of the application when another instance of the application at another virtual machine is waiting to obtain the lock.
16. The computer-implemented method of claim 11, wherein:
the first instance of the application releases the lock, responsive to the command, when it exits a synchronization method.
17. A computer-implemented method for controlling locks in a virtual machine cluster, comprising:
receiving from a first instance of an application running at a first virtual machine, a request for a lock affecting a managed object;
responsive to the request, determining whether any other instance of the application running at any other virtual machine currently has the lock; and
informing the first virtual machine of whether the lock is granted based on said determining step.
18. The computer-implemented method of claim 17 further including the step of communicating a message to the first virtual machine indicating that the lock is granted.
19. The computer-implemented method of claim 17, wherein:
the step of informing comprises informing the first virtual machine the lock is not granted if any virtual machine in the cluster currently has a lock until said virtual machine releases the lock.
20. The computer-implemented method of claim 19 further includes:
arbitrating requests for the lock by all instances of the application so that the lock is granted to only one instance of the application at a time.
21. The computer-implemented method of claim 17 further including the step of receiving a request from a second virtual machine requesting a lock previously granted to a virtual machine and denying the request.
22. The computer-implemented method of claim 21, further comprising:
receiving a notification from the first virtual machine holding a lock indicating that the first instance of the application is releasing the lock.
23. The computer-implemented method of claim 22 further including the step of notifying the second virtual machine that the lock is granted to said virtual machine.
24. The computer-implemented method of claim 17, wherein the method further includes receiving a request from a second virtual machine for a lock held by a first virtual machine, and commanding the first virtual machine to release the lock, the first virtual machine holding the lock until it receives the command.
25. The computer-implemented method of claim 24, wherein:
the central manager provides the command to release the lock when another instance of the application at another virtual machine is waiting to obtain the lock.
US11/442,523 2005-05-25 2006-05-25 Lock management for clustered virtual machines Abandoned US20070011667A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US68461005P true 2005-05-25 2005-05-25
US11/442,523 US20070011667A1 (en) 2005-05-25 2006-05-25 Lock management for clustered virtual machines

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US11/442,523 US20070011667A1 (en) 2005-05-25 2006-05-25 Lock management for clustered virtual machines

Publications (1)

Publication Number Publication Date
US20070011667A1 true US20070011667A1 (en) 2007-01-11

Family

ID=37452936

Family Applications (10)

Application Number Title Priority Date Filing Date
US11/441,677 Abandoned US20060271931A1 (en) 2005-05-25 2006-05-25 Distributed signaling in a virtual machine cluster
US11/442,522 Abandoned US20060271575A1 (en) 2005-05-25 2006-05-25 Clustered object state using field set operations
US11/441,676 Abandoned US20060271930A1 (en) 2005-05-25 2006-05-25 Clustered object state using synthetic transactions
US11/420,460 Abandoned US20060271557A1 (en) 2005-05-25 2006-05-25 Database Caching and Invalidation Based on Detected Database Updates
US11/442,524 Abandoned US20060271542A1 (en) 2005-05-25 2006-05-25 Clustered object state using logical actions
US11/441,605 Abandoned US20060271395A1 (en) 2005-05-25 2006-05-25 Distributed object identity in a virtual machine cluster
US11/420,451 Abandoned US20060271510A1 (en) 2005-05-25 2006-05-25 Database Caching and Invalidation using Database Provided Facilities for Query Dependency Analysis
US11/442,523 Abandoned US20070011667A1 (en) 2005-05-25 2006-05-25 Lock management for clustered virtual machines
US11/420,466 Abandoned US20060271511A1 (en) 2005-05-25 2006-05-25 Database Caching and Invalidation for Stored Procedures
US11/420,446 Active 2027-03-20 US7716377B2 (en) 2005-05-25 2006-05-25 Clustering server providing virtual machine data sharing

Family Applications Before (7)

Application Number Title Priority Date Filing Date
US11/441,677 Abandoned US20060271931A1 (en) 2005-05-25 2006-05-25 Distributed signaling in a virtual machine cluster
US11/442,522 Abandoned US20060271575A1 (en) 2005-05-25 2006-05-25 Clustered object state using field set operations
US11/441,676 Abandoned US20060271930A1 (en) 2005-05-25 2006-05-25 Clustered object state using synthetic transactions
US11/420,460 Abandoned US20060271557A1 (en) 2005-05-25 2006-05-25 Database Caching and Invalidation Based on Detected Database Updates
US11/442,524 Abandoned US20060271542A1 (en) 2005-05-25 2006-05-25 Clustered object state using logical actions
US11/441,605 Abandoned US20060271395A1 (en) 2005-05-25 2006-05-25 Distributed object identity in a virtual machine cluster
US11/420,451 Abandoned US20060271510A1 (en) 2005-05-25 2006-05-25 Database Caching and Invalidation using Database Provided Facilities for Query Dependency Analysis

Family Applications After (2)

Application Number Title Priority Date Filing Date
US11/420,466 Abandoned US20060271511A1 (en) 2005-05-25 2006-05-25 Database Caching and Invalidation for Stored Procedures
US11/420,446 Active 2027-03-20 US7716377B2 (en) 2005-05-25 2006-05-25 Clustering server providing virtual machine data sharing

Country Status (2)

Country Link
US (10) US20060271931A1 (en)
WO (2) WO2006128062A2 (en)

Cited By (39)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070169055A1 (en) * 2005-12-12 2007-07-19 Bernd Greifeneder Method and system for automated analysis of the performance of remote method invocations in multi-tier applications using bytecode instrumentation
US20080098309A1 (en) * 2006-10-24 2008-04-24 Microsoft Corporation Managing virtual machines and hosts by property
US20080243847A1 (en) * 2007-04-02 2008-10-02 Microsoft Corporation Separating central locking services from distributed data fulfillment services in a storage system
US20080243846A1 (en) * 2007-04-02 2008-10-02 Microsoft Corporation Locking semantics for a storage system based on file types
US20080276227A1 (en) * 2007-05-06 2008-11-06 Bernd Greifeneder Method and System for Adaptive, Generic Code Instrumentation using Run-time or Load-time generated Inheritance Information for Diagnosis and Monitoring Application Performance and Failure
US20080320561A1 (en) * 2007-06-22 2008-12-25 Suit John M Method and System for Collaboration Involving Enterprise Nodes
US20080320592A1 (en) * 2007-06-22 2008-12-25 Suit John M Method and system for cloaked observation and remediation of software attacks
US20080320499A1 (en) * 2007-06-22 2008-12-25 Suit John M Method and System for Direct Insertion of a Virtual Machine Driver
US20080320583A1 (en) * 2007-06-22 2008-12-25 Vipul Sharma Method for Managing a Virtual Machine
US20090132997A1 (en) * 2007-11-21 2009-05-21 John Douglas Frazier Techniques for constructing and using run-time java archives (jar) for java stored procedures (jsps)
US20090183173A1 (en) * 2007-06-22 2009-07-16 Daniel Lee Becker Method and system for determining a host machine by a virtual machine
US20090182928A1 (en) * 2007-06-22 2009-07-16 Daniel Lee Becker Method and system for tracking a virtual machine
US20090217276A1 (en) * 2008-02-27 2009-08-27 Brenner Larry B Method and apparatus for moving threads in a shared processor partitioning environment
US20090320011A1 (en) * 2008-06-20 2009-12-24 Vmware, Inc. Accelerating replayed program execution to support decoupled program analysis
US20100077078A1 (en) * 2007-06-22 2010-03-25 Fortisphere, Inc. Network traffic analysis using a dynamically updating ontological network description
US20100082941A1 (en) * 2008-09-30 2010-04-01 Duvalsaint Karl J Delegated virtualization in a multi-core processor (mcp)
US20100131945A1 (en) * 2008-11-25 2010-05-27 Sap Ag System and method of implementing a concurrency profiler
US7757215B1 (en) * 2006-04-11 2010-07-13 Oracle America, Inc. Dynamic fault injection during code-testing using a dynamic tracing framework
US20100332593A1 (en) * 2009-06-29 2010-12-30 Igor Barash Systems and methods for operating an anti-malware network on a cloud computing platform
US20110214024A1 (en) * 2010-02-26 2011-09-01 Bmc Software, Inc. Method of Collecting and Correlating Locking Data to Determine Ultimate Holders in Real Time
US20120131538A1 (en) * 2010-11-23 2012-05-24 Kushal Das Mechanism for determining support criteria for shared libraries based on their priority levels
US20120131564A1 (en) * 2010-11-23 2012-05-24 Kushal Das Process Of Finding Out If Software Will Run On An Operating System Without Installing That Software
US20120179778A1 (en) * 2010-01-22 2012-07-12 Brutesoft, Inc. Applying networking protocols to image file management
WO2012118268A2 (en) * 2011-02-28 2012-09-07 ㈜지노게임즈 Multi-thread processing system using a multi-virtual machine, and method therefor
US8533687B1 (en) 2009-11-30 2013-09-10 dynaTrade Software GmbH Methods and system for global real-time transaction tracing
US8863093B1 (en) * 2009-03-06 2014-10-14 Coverity, Inc. Load-time instrumentation of virtual machine program code
US8887122B2 (en) 2010-11-23 2014-11-11 Red Hat, Inc. Find and track information of interface usage of software libraries by other software
US8938706B2 (en) 2010-11-23 2015-01-20 Red Hat, Inc. Providing customized visualization of application binary interface/application programming interface-related information
US8997048B1 (en) * 2007-02-14 2015-03-31 Oracle America, Inc. Method and apparatus for profiling a virtual machine
US9047412B2 (en) 2007-05-06 2015-06-02 Dynatrace Corporation System and method for extracting instrumentation relevant inheritance relationships for a distributed, inheritance rule based instrumentation system
US9231858B1 (en) 2006-08-11 2016-01-05 Dynatrace Software Gmbh Completeness detection of monitored globally distributed synchronous and asynchronous transactions
US9274919B2 (en) 2011-04-29 2016-03-01 Dynatrace Software Gmbh Transaction tracing mechanism of distributed heterogenous transactions having instrumented byte code with constant memory consumption and independent of instrumented method call depth
US9354960B2 (en) 2010-12-27 2016-05-31 Red Hat, Inc. Assigning virtual machines to business application service groups based on ranking of the virtual machines
US9361160B2 (en) 2008-09-30 2016-06-07 International Business Machines Corporation Virtualization across physical partitions of a multi-core processor (MCP)
US9477572B2 (en) 2007-06-22 2016-10-25 Red Hat, Inc. Performing predictive modeling of virtual machine relationships
US9569330B2 (en) 2007-06-22 2017-02-14 Red Hat, Inc. Performing dependency analysis on nodes of a business application service group
US9727440B2 (en) 2007-06-22 2017-08-08 Red Hat, Inc. Automatic simulation of virtual machine performance
US10133607B2 (en) 2007-06-22 2018-11-20 Red Hat, Inc. Migration of network entities to a cloud infrastructure
US10163547B2 (en) * 2017-03-31 2018-12-25 Hitachi Metals, Ltd. Linear filler padded composite cable

Families Citing this family (217)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7904187B2 (en) 1999-02-01 2011-03-08 Hoffberg Steven M Internet appliance system and method
US8352400B2 (en) 1991-12-23 2013-01-08 Hoffberg Steven M Adaptive pattern recognition based controller apparatus and method and human-factored interface therefore
GB0112781D0 (en) 2001-05-25 2001-07-18 Global Continuity Plc Method for rapid recovery from a network file server failure
US7529897B1 (en) 2003-12-31 2009-05-05 Vmware, Inc. Generating and using checkpoints in a virtual computer system
US9606821B2 (en) * 2004-12-17 2017-03-28 Intel Corporation Virtual environment manager for creating and managing virtual machine environments
US7480822B1 (en) * 2005-07-13 2009-01-20 Symantec Corporation Recovery and operation of captured running states from multiple computing systems on a single computing system
US20070016628A1 (en) * 2005-07-14 2007-01-18 Lenevo (Singapore) Pte.Ltd. Classification system for versionable objects
US8166458B2 (en) * 2005-11-07 2012-04-24 Red Hat, Inc. Method and system for automated distributed software testing
US9135304B2 (en) * 2005-12-02 2015-09-15 Salesforce.Com, Inc. Methods and systems for optimizing text searches over structured data in a multi-tenant environment
US8225315B1 (en) * 2007-07-23 2012-07-17 Oracle America, Inc. Virtual core management
US7792875B2 (en) * 2006-03-30 2010-09-07 International Business Machines Corporation Method for representing and recreating object dependencies from one database system to another
US8286174B1 (en) * 2006-04-17 2012-10-09 Vmware, Inc. Executing a multicomponent software application on a virtualized computer platform
US7797329B2 (en) * 2006-06-09 2010-09-14 Oracle America Inc. Method and system for enabling a synchronization-free and parallel commit phase
US7529827B2 (en) * 2006-06-29 2009-05-05 Stratavia Corporation Standard operating procedure automation in database administration
WO2008019380A2 (en) * 2006-08-07 2008-02-14 Bea Systems, Inc. System and method for providing hardware virtualization in a virtual machine environment
US7831620B2 (en) * 2006-08-31 2010-11-09 International Business Machines Corporation Managing execution of a query against a partitioned database
US8056141B2 (en) * 2006-09-13 2011-11-08 Imperva, Inc. Method for monitoring stored procedures
US9697253B2 (en) * 2006-10-20 2017-07-04 Oracle International Corporation Consistent client-side cache
US10296629B2 (en) * 2006-10-20 2019-05-21 Oracle International Corporation Server supporting a consistent client-side cache
US20080104588A1 (en) * 2006-10-27 2008-05-01 Barber Michael J Creation of temporary virtual machine clones of multiple operating systems
US8082344B2 (en) * 2007-02-12 2011-12-20 Microsoft Corporation Transaction manager virtualization
US7853950B2 (en) * 2007-04-05 2010-12-14 International Business Machines Corporarion Executing multiple threads in a processor
US8151277B2 (en) * 2007-05-15 2012-04-03 Dynatrace Software Gmbh Method and system for dynamic remote injection of in-process agents into virtual machine based applications
KR100911324B1 (en) * 2007-06-22 2009-08-07 삼성전자주식회사 Method for managing variability point and appratus therefor
US7941411B2 (en) * 2007-06-29 2011-05-10 Microsoft Corporation Memory transaction grouping
US9715438B2 (en) * 2007-06-29 2017-07-25 International Business Machines Corporation Static execution of statements in a program
US8074094B2 (en) * 2007-06-30 2011-12-06 Cisco Technology, Inc. Session redundancy using a replay model
US7882198B2 (en) * 2007-07-02 2011-02-01 Oracle America, Inc. Shared JAVA JAR files
US8966488B2 (en) * 2007-07-06 2015-02-24 XMOS Ltd. Synchronising groups of threads with dedicated hardware logic
US8799903B1 (en) * 2007-07-31 2014-08-05 Hewlett-Packard Development Company, L.P. Systems and methods for exchanging runtime functionalities between software stacks
US8458670B2 (en) * 2007-09-27 2013-06-04 Symantec Corporation Automatically adding bytecode to a software application to determine network communication information
US8245217B2 (en) 2007-10-12 2012-08-14 Microsoft Corporation Management of software and operating system updates required for the process of creating a virtual machine facsimile of an existing physical or virtual machine
US8370370B2 (en) * 2007-10-15 2013-02-05 International Business Machines Corporation Bridging real-world web applications and 3D virtual worlds
CN101430687B (en) * 2007-11-09 2015-11-25 阿里巴巴集团控股有限公司 Based on statistics application method and system environment oltp
US8595369B2 (en) * 2007-11-13 2013-11-26 Vmware, Inc. Method and system for correlating front-end and back-end transactions in a data center
US8326814B2 (en) 2007-12-05 2012-12-04 Box, Inc. Web-based file management system and service
US8468440B2 (en) * 2007-12-21 2013-06-18 The Invention Science Fund I, Llc Look ahead of links/alter links
US8495486B2 (en) * 2007-12-21 2013-07-23 The Invention Science Fund I, Llc Look ahead of links/alter links
US20090165134A1 (en) * 2007-12-21 2009-06-25 Searete Llc, A Limited Liability Corporation Of The State Of Delaware Look ahead of links/alter links
US8793616B2 (en) 2007-12-21 2014-07-29 The Invention Science Fund I, Llc Look ahead of links/alter links
US8473836B2 (en) * 2007-12-21 2013-06-25 The Invention Science Fund I, Llc Look ahead of links/alter links
US8949977B2 (en) * 2007-12-21 2015-02-03 The Invention Science Fund I, Llc Look ahead of links/alter links
US8489981B2 (en) * 2007-12-21 2013-07-16 The Invention Science Fund I, Llc Look ahead of links/alter links
US8706796B2 (en) * 2007-12-27 2014-04-22 SAP France S.A. Managing a cluster of computers
US9600438B2 (en) * 2008-01-03 2017-03-21 Florida Institute For Human And Machine Cognition, Inc. Process integrated mechanism apparatus and program
US9116715B2 (en) * 2008-02-04 2015-08-25 Rightscale, Inc. Systems and methods for efficiently booting and configuring virtual servers
US8650154B2 (en) 2008-02-19 2014-02-11 International Business Machines Corporation Document synchronization solution
US20090240930A1 (en) * 2008-03-24 2009-09-24 International Business Machines Corporation Executing An Application On A Parallel Computer
US8646052B2 (en) * 2008-03-31 2014-02-04 Intel Corporation Method and apparatus for providing a secure display window inside the primary display
US8725679B2 (en) * 2008-04-07 2014-05-13 International Business Machines Corporation Client side caching of synchronized data
US8281311B2 (en) * 2008-04-24 2012-10-02 International Business Machines Corporation Executing a distributed software application on a plurality of compute nodes according to a compilation history
US8185901B2 (en) 2008-04-24 2012-05-22 International Business Machines Corporation Parsing an application to find serial and parallel data segments to minimize migration overhead between serial and parallel compute nodes
US8161483B2 (en) 2008-04-24 2012-04-17 International Business Machines Corporation Configuring a parallel computer based on an interleave rate of an application containing serial and parallel segments
US9086924B2 (en) * 2008-04-24 2015-07-21 International Business Machines Corporation Executing a distributed java application on a plurality of compute nodes
WO2009138123A1 (en) * 2008-05-15 2009-11-19 Simeon Falk Sheye A method for automatic testing of software
US8561062B2 (en) * 2008-05-30 2013-10-15 Red Hat, Inc. Synchronizing changes made on self-replicated machines to the corresponding parent machines
US8375387B2 (en) * 2008-05-30 2013-02-12 Red Hat, Inc. Product independent orchestration tool
US8239416B2 (en) * 2008-05-30 2012-08-07 Armanta, Inc. System, method, and computer program product for modeling changes to large scale datasets
US8615758B2 (en) * 2008-05-30 2013-12-24 Red Hat, Inc. Combining system blueprints, functional layer, and software bits in parallel development of machines
US8516494B2 (en) * 2008-06-16 2013-08-20 International Business Machines Corporation Executing an application on a parallel computer
US9100246B1 (en) * 2008-06-19 2015-08-04 Symantec Corporation Distributed application virtualization
US20100082702A1 (en) * 2008-09-29 2010-04-01 Honeywell International Inc. Dynamic vehicle information management
US8195707B1 (en) * 2008-09-30 2012-06-05 Adobe Systems Incorporated Identifying and reacting to changes in an extensible automatic runtime object management system
US20100088698A1 (en) * 2008-10-03 2010-04-08 Ravishankar Krishnamurthy Techniques for managing communication sessions
JP5213077B2 (en) * 2008-10-06 2013-06-19 インターナショナル・ビジネス・マシーンズ・コーポレーションInternational Business Machines Corporation System for accessing the shared data by a plurality of application servers
US20100153693A1 (en) * 2008-12-17 2010-06-17 Microsoft Corporation Code execution with automated domain switching
US20100161643A1 (en) * 2008-12-24 2010-06-24 Yahoo! Inc. Segmentation of interleaved query missions into query chains
US9292557B2 (en) * 2009-02-27 2016-03-22 Red Hat Israel, Ltd. Managing virtual machines using hierarchical labeling
US9104757B2 (en) * 2009-06-24 2015-08-11 Red Hat Israel, Ltd. Interactive search monitoring in a virtual machine environment
JP5458708B2 (en) * 2009-07-09 2014-04-02 株式会社リコー Image processing apparatus, display control method, and a display control program
US20110035802A1 (en) * 2009-08-07 2011-02-10 Microsoft Corporation Representing virtual object priority based on relationships
US9594782B2 (en) * 2013-12-23 2017-03-14 Ic Manage, Inc. Hierarchical file block variant store apparatus and method of operation
US9143597B2 (en) * 2009-09-21 2015-09-22 Avaya Inc. Method for telephony client synchronization in telephone virtualization
US9338273B2 (en) * 2009-09-22 2016-05-10 Avaya Inc. Method for telephony client synchronization in telephone virtualization
US8718611B2 (en) * 2009-09-30 2014-05-06 Avaya Inc. Method for the selection of an active software environment of a virtualized telecommunications terminal
US8407723B2 (en) * 2009-10-08 2013-03-26 Tibco Software, Inc. JAVA virtual machine having integrated transaction management system and facility to query managed objects
US8244682B2 (en) * 2009-10-23 2012-08-14 Clausal Computing Oy Saving snapshot of a knowledge base without blocking
US9094426B2 (en) 2009-11-20 2015-07-28 Avaya Inc. Method for telecommunications device synchronization
CN102073512B (en) 2009-11-23 2014-07-16 阿里巴巴集团控股有限公司 JAVA cluster application system code loading and upgrading device and method
US8352953B2 (en) * 2009-12-03 2013-01-08 International Business Machines Corporation Dynamically provisioning virtual machines
US8311032B2 (en) * 2009-12-03 2012-11-13 International Business Machines Corporation Dynamically provisioning virtual machines
EP2513789A4 (en) 2009-12-14 2016-09-14 Citrix Systems Inc A secure virtualization environment bootable from an external media device
EP3002703B1 (en) * 2009-12-14 2017-08-30 Citrix Systems Inc. Methods and systems for communicating between trusted and non-trusted virtual machines
US20110173177A1 (en) * 2010-01-11 2011-07-14 Flavio Junqueira Sightful cache: efficient invalidation for search engine caching
US20110173947A1 (en) * 2010-01-19 2011-07-21 General Electric Company System and method for gas turbine power augmentation
US8874914B2 (en) * 2010-02-05 2014-10-28 Accenture Global Services Limited Secure and automated credential information transfer mechanism
US8862563B2 (en) * 2010-05-12 2014-10-14 Microsoft Corporation Getting dependency metadata using statement execution plans
US8990802B1 (en) * 2010-05-24 2015-03-24 Thinking Software, Inc. Pinball virtual machine (PVM) implementing computing process within a structural space using PVM atoms and PVM atomic threads
US9075635B1 (en) * 2010-07-26 2015-07-07 Symantec Corporation Systems and methods for merging virtual layers
EP2447836A1 (en) * 2010-10-18 2012-05-02 Simulity Labs Ltd Multiple virtual machine engines on a single card
US8418185B2 (en) 2010-10-19 2013-04-09 International Business Machines Corporation Memory maximization in a high input/output virtual machine environment
US8751656B2 (en) 2010-10-20 2014-06-10 Microsoft Corporation Machine manager for deploying and managing machines
US8386501B2 (en) 2010-10-20 2013-02-26 Microsoft Corporation Dynamically splitting multi-tenant databases
US8799453B2 (en) 2010-10-20 2014-08-05 Microsoft Corporation Managing networks and machines for an online service
US8296267B2 (en) 2010-10-20 2012-10-23 Microsoft Corporation Upgrade of highly available farm server groups
US8417737B2 (en) 2010-10-20 2013-04-09 Microsoft Corporation Online database availability during upgrade
US9075661B2 (en) 2010-10-20 2015-07-07 Microsoft Technology Licensing, Llc Placing objects on hosts using hard and soft constraints
US8719402B2 (en) 2010-10-21 2014-05-06 Microsoft Corporation Goal state communication in computer clusters
US8910155B1 (en) * 2010-11-02 2014-12-09 Symantec Corporation Methods and systems for injecting endpoint management agents into virtual machines
US9141415B2 (en) * 2010-11-16 2015-09-22 Syddansk Universitet Method for dynamically transforming the bytecode of Java virtual machine bootstrap classes
US8850550B2 (en) 2010-11-23 2014-09-30 Microsoft Corporation Using cached security tokens in an online service
US9032146B2 (en) 2010-11-30 2015-05-12 Lenovo Enterprise Solutions (Singapore) Pte. Ltd. Dynamic use of raid levels responsive to workload requirements
US20120137062A1 (en) * 2010-11-30 2012-05-31 International Business Machines Corporation Leveraging coalesced memory
US9721030B2 (en) 2010-12-09 2017-08-01 Microsoft Technology Licensing, Llc Codeless sharing of spreadsheet objects
US9589029B2 (en) * 2010-12-28 2017-03-07 Citrix Systems, Inc. Systems and methods for database proxy request switching
US8677356B2 (en) * 2011-01-11 2014-03-18 International Business Machines Corporation Adjunct partition work scheduling with quality of service attributes
US8990823B2 (en) 2011-03-10 2015-03-24 International Business Machines Corporation Optimizing virtual machine synchronization for application software
US9122720B2 (en) * 2011-06-14 2015-09-01 Microsoft Technology Licensing, Llc Enriching database query responses using data from external data sources
US9015601B2 (en) 2011-06-21 2015-04-21 Box, Inc. Batch uploading of content to a web-based collaboration environment
US8832690B1 (en) 2011-06-21 2014-09-09 Google Inc. Multi-threaded virtual machine processing on a web page
US9063912B2 (en) 2011-06-22 2015-06-23 Box, Inc. Multimedia content preview rendering in a cloud content management system
US8719232B2 (en) * 2011-06-30 2014-05-06 Verisign, Inc. Systems and methods for data integrity checking
US8615503B2 (en) * 2011-07-01 2013-12-24 International Business Machines Corporation Method for attaching partition online to range partitioned table
US9176829B2 (en) 2011-07-01 2015-11-03 Microsoft Technology Licensing, Llc Managing recovery virtual machines in clustered environment
US8914466B2 (en) 2011-07-07 2014-12-16 International Business Machines Corporation Multi-level adaptive caching within asset-based web systems
EP2729877A4 (en) 2011-07-08 2015-06-17 Box Inc Desktop application for access and interaction with workspaces in a cloud-based content management system and synchronization mechanisms thereof
US9978040B2 (en) 2011-07-08 2018-05-22 Box, Inc. Collaboration sessions in a workspace on a cloud-based content management system
US9361162B1 (en) * 2011-08-26 2016-06-07 Amazon Technologies, Inc. Executing threads of an application across multiple computing devices in a distributed virtual machine environment
US20130060795A1 (en) * 2011-09-07 2013-03-07 Unisys Corp. Prepared statements to improve performance in database interfaces
US20130074065A1 (en) * 2011-09-21 2013-03-21 Ibm Corporation Maintaining Consistency of Storage in a Mirrored Virtual Environment
US9197718B2 (en) 2011-09-23 2015-11-24 Box, Inc. Central management and control of user-contributed content in a web-based collaboration environment and management console thereof
US8515902B2 (en) 2011-10-14 2013-08-20 Box, Inc. Automatic and semi-automatic tagging features of work items in a shared workspace for metadata tracking in a cloud-based content management system with selective or optional user contribution
DE102011116866A1 (en) * 2011-10-25 2013-04-25 Fujitsu Technology Solutions Intellectual Property Gmbh Cluster system and method for executing a plurality of virtual machines
US9098474B2 (en) 2011-10-26 2015-08-04 Box, Inc. Preview pre-generation based on heuristics and algorithmic prediction/assessment of predicted user behavior for enhancement of user experience
US8990307B2 (en) * 2011-11-16 2015-03-24 Box, Inc. Resource effective incremental updating of a remote client with events which occurred via a cloud-enabled platform
GB2500152A (en) 2011-11-29 2013-09-11 Box Inc Mobile platform file and folder selection functionalities for offline access and synchronization
WO2013088301A1 (en) * 2011-12-12 2013-06-20 International Business Machines Corporation Maintenance of offline virtual machines based on maintenance register
US20130152081A1 (en) 2011-12-13 2013-06-13 International Business Machines Corporation Selectable event reporting for highly virtualized partitioned systems
US9019123B2 (en) 2011-12-22 2015-04-28 Box, Inc. Health check services for web-based collaboration environments
US9904435B2 (en) 2012-01-06 2018-02-27 Box, Inc. System and method for actionable event generation for task delegation and management via a discussion forum in a web-based collaboration environment
US9135310B2 (en) * 2012-01-30 2015-09-15 Memsql, Inc. Query routing in a distributed database system
US9317552B2 (en) * 2012-01-30 2016-04-19 Memsql, Inc. Reusing existing query plans in a database system
US9965745B2 (en) 2012-02-24 2018-05-08 Box, Inc. System and method for promoting enterprise adoption of a web-based collaboration environment
KR101878297B1 (en) * 2012-03-06 2018-08-07 삼성전자주식회사 Method and apparatus for recovering lock holder preemption
US9195636B2 (en) 2012-03-07 2015-11-24 Box, Inc. Universal file type preview for mobile devices
US8694961B2 (en) * 2012-04-03 2014-04-08 Microsoft Corporation Thread-agile execution of dynamic programming language programs
US9054919B2 (en) 2012-04-05 2015-06-09 Box, Inc. Device pinning capability for enterprise cloud service and storage accounts
US9575981B2 (en) 2012-04-11 2017-02-21 Box, Inc. Cloud service enabled to handle a set of files depicted to a user as a single file in a native operating system
US8881149B2 (en) * 2012-04-11 2014-11-04 International Business Machines Corporation Control of java resource runtime usage
US9922133B2 (en) * 2012-04-16 2018-03-20 Entit Software Llc Live topological query
US9413587B2 (en) 2012-05-02 2016-08-09 Box, Inc. System and method for a third-party application to access content within a cloud-based platform
US9691051B2 (en) 2012-05-21 2017-06-27 Box, Inc. Security enhancement through application access control
US8914900B2 (en) 2012-05-23 2014-12-16 Box, Inc. Methods, architectures and security mechanisms for a third-party application to access content in a cloud-based platform
US9027108B2 (en) 2012-05-23 2015-05-05 Box, Inc. Systems and methods for secure file portability between mobile applications on a mobile device
US9021099B2 (en) 2012-07-03 2015-04-28 Box, Inc. Load balancing secure FTP connections among multiple FTP servers
US20140012704A1 (en) 2012-07-05 2014-01-09 Google Inc. Selecting a preferred payment instrument based on a merchant category
US9792320B2 (en) 2012-07-06 2017-10-17 Box, Inc. System and method for performing shard migration to support functions of a cloud-based service
US9712510B2 (en) 2012-07-06 2017-07-18 Box, Inc. Systems and methods for securely submitting comments among users via external messaging applications in a cloud-based platform
US9152449B2 (en) 2012-07-13 2015-10-06 International Business Machines Corporation Co-location of virtual machines with nested virtualization
US9237170B2 (en) 2012-07-19 2016-01-12 Box, Inc. Data loss prevention (DLP) methods and architectures by a cloud service
US8868574B2 (en) 2012-07-30 2014-10-21 Box, Inc. System and method for advanced search and filtering mechanisms for enterprise administrators in a cloud-based environment
US9794256B2 (en) 2012-07-30 2017-10-17 Box, Inc. System and method for advanced control tools for administrators in a cloud-based service
US8972971B2 (en) * 2012-08-09 2015-03-03 International Business Machines Corporation Image instance mapping
US9369520B2 (en) 2012-08-19 2016-06-14 Box, Inc. Enhancement of upload and/or download performance based on client and/or server feedback information
US8745267B2 (en) 2012-08-19 2014-06-03 Box, Inc. Enhancement of upload and/or download performance based on client and/or server feedback information
GB2513671A (en) 2012-08-27 2014-11-05 Box Inc Server side techniques for reducing database workload in implementing selective subfolder synchronization in a cloud-based environment
US9135462B2 (en) 2012-08-29 2015-09-15 Box, Inc. Upload and download streaming encryption to/from a cloud-based platform
US9311071B2 (en) 2012-09-06 2016-04-12 Box, Inc. Force upgrade of a mobile application via a server side configuration file
US9117087B2 (en) 2012-09-06 2015-08-25 Box, Inc. System and method for creating a secure channel for inter-application communication based on intents
US9195519B2 (en) 2012-09-06 2015-11-24 Box, Inc. Disabling the self-referential appearance of a mobile application in an intent via a background registration
US9292833B2 (en) 2012-09-14 2016-03-22 Box, Inc. Batching notifications of activities that occur in a web-based collaboration environment
US10200256B2 (en) 2012-09-17 2019-02-05 Box, Inc. System and method of a manipulative handle in an interactive mobile user interface
US9553758B2 (en) 2012-09-18 2017-01-24 Box, Inc. Sandboxing individual applications to specific user folders in a cloud-based service
US9959420B2 (en) 2012-10-02 2018-05-01 Box, Inc. System and method for enhanced security and management mechanisms for enterprise administrators in a cloud-based environment
US9495364B2 (en) 2012-10-04 2016-11-15 Box, Inc. Enhanced quick search features, low-barrier commenting/interactive features in a collaboration platform
US9705967B2 (en) 2012-10-04 2017-07-11 Box, Inc. Corporate user discovery and identification of recommended collaborators in a cloud platform
US9665349B2 (en) 2012-10-05 2017-05-30 Box, Inc. System and method for generating embeddable widgets which enable access to a cloud-based collaboration platform
GB2507191B (en) 2012-10-17 2015-03-04 Box Inc Remote key management in a cloud-based environment
US20140129513A1 (en) * 2012-11-08 2014-05-08 Callidus Software Incorporated Subset calculation by identifying calculated values with modified parameters
US9183271B2 (en) * 2012-12-04 2015-11-10 Pivotal Software, Inc. Big-fast data connector between in-memory database system and data warehouse system
US10235383B2 (en) 2012-12-19 2019-03-19 Box, Inc. Method and apparatus for synchronization of items with read-only permissions in a cloud-based environment
US9336024B1 (en) * 2012-12-27 2016-05-10 Google Inc. Clustering for parallel processing
US9396245B2 (en) 2013-01-02 2016-07-19 Box, Inc. Race condition handling in a system which incrementally updates clients with events that occurred in a cloud-based collaboration platform
US9953036B2 (en) 2013-01-09 2018-04-24 Box, Inc. File system monitoring in a system which incrementally updates clients with events that occurred in a cloud-based collaboration platform
EP2755151A3 (en) 2013-01-11 2014-09-24 Box, Inc. Functionalities, features and user interface of a synchronization client to a cloud-based environment
US9092767B1 (en) * 2013-03-04 2015-07-28 Google Inc. Selecting a preferred payment instrument
CN105190565B (en) * 2013-03-14 2019-01-18 英特尔公司 Memory object reference count management with improved scalability
US9235618B2 (en) * 2013-04-06 2016-01-12 Citrix Systems, Inc. Systems and methods for caching of SQL responses using integrated caching
US9658899B2 (en) * 2013-06-10 2017-05-23 Amazon Technologies, Inc. Distributed lock management in a cloud computing environment
GB2515192B (en) 2013-06-13 2016-12-14 Box Inc Systems and methods for synchronization event building and/or collapsing by a synchronization component of a cloud-based platform
US9805050B2 (en) 2013-06-21 2017-10-31 Box, Inc. Maintaining and updating file system shadows on a local device by a synchronization client of a cloud-based platform
US10229134B2 (en) 2013-06-25 2019-03-12 Box, Inc. Systems and methods for managing upgrades, migration of user data and improving performance of a cloud-based platform
US10110656B2 (en) 2013-06-25 2018-10-23 Box, Inc. Systems and methods for providing shell communication in a cloud-based platform
US9535924B2 (en) 2013-07-30 2017-01-03 Box, Inc. Scalability improvement in a system which incrementally updates clients with events that occurred in a cloud-based collaboration platform
US9600514B2 (en) 2013-09-09 2017-03-21 VoltDB, Inc. Methods and systems for detecting data divergence and inconsistency across replicas of data within a shared-nothing distributed database
US10176240B2 (en) 2013-09-12 2019-01-08 VoltDB, Inc. Methods and systems for real-time transactional database transformation
US8892679B1 (en) 2013-09-13 2014-11-18 Box, Inc. Mobile device, methods and user interfaces thereof in a mobile device platform featuring multifunctional access and engagement in a collaborative environment provided by a cloud-based platform
US9704137B2 (en) 2013-09-13 2017-07-11 Box, Inc. Simultaneous editing/accessing of content by collaborator invitation through a web-based or mobile application to a cloud-based collaboration platform
GB2518298A (en) 2013-09-13 2015-03-18 Box Inc High-availability architecture for a cloud-based concurrent-access collaboration platform
US9535909B2 (en) 2013-09-13 2017-01-03 Box, Inc. Configurable event-based automation architecture for cloud-based collaboration platforms
US9213684B2 (en) 2013-09-13 2015-12-15 Box, Inc. System and method for rendering document in web browser or mobile device regardless of third-party plug-in software
US10303682B2 (en) * 2013-09-21 2019-05-28 Oracle International Corporation Automatic verification and triage of query results
US9515901B2 (en) 2013-10-18 2016-12-06 AppDynamics, Inc. Automatic asynchronous handoff identification
US9922043B1 (en) 2013-10-28 2018-03-20 Pivotal Software, Inc. Data management platform
US9639544B1 (en) * 2013-10-28 2017-05-02 Pivotal Software, Inc. Table data persistence
US9274828B2 (en) 2013-11-03 2016-03-01 Maestrano Pty Ltd. Systems and methods for event driven object management and distribution among multiple client applications
US9639571B2 (en) 2013-12-30 2017-05-02 VoltDB, Inc. Methods and systems for increasing capacity and performing data rebalancing without downtime to a distributed shared-nothing database with serializable isolation
US9858572B2 (en) 2014-02-06 2018-01-02 Google Llc Dynamic alteration of track data
GB2524075A (en) * 2014-03-14 2015-09-16 Ibm Advanced result cache refill
EP3146426A4 (en) * 2014-05-21 2018-01-03 Georgia State University Research Foundation, Inc. High-performance computing framework for cloud computing environments
US9602514B2 (en) 2014-06-16 2017-03-21 Box, Inc. Enterprise mobility management and verification of a managed application by a content provider
US10097410B2 (en) * 2014-06-26 2018-10-09 Vmware, Inc. Methods and apparatus to scale application deployments in cloud computing environments
US9369406B2 (en) * 2014-07-03 2016-06-14 Sas Institute Inc. Resource server providing a rapidly changing resource
US10200258B2 (en) * 2014-08-14 2019-02-05 Juniper Networks, Inc. Transaction integrity for network services configuration
CN105446792A (en) * 2014-08-27 2016-03-30 联想(北京)有限公司 Deployment method, deployment device and management node of virtual machines
US9756022B2 (en) 2014-08-29 2017-09-05 Box, Inc. Enhanced remote key management for an enterprise in a cloud-based environment
US9894119B2 (en) 2014-08-29 2018-02-13 Box, Inc. Configurable metadata-based automation and content classification architecture for cloud-based collaboration platforms
US10038731B2 (en) 2014-08-29 2018-07-31 Box, Inc. Managing flow-based interactions with cloud-based shared content
US9529691B2 (en) 2014-10-31 2016-12-27 AppDynamics, Inc. Monitoring and correlating a binary process in a distributed business transaction
US20160125029A1 (en) * 2014-10-31 2016-05-05 InsightSoftware.com International Intelligent caching for enterprise resource planning reporting
US9535811B2 (en) 2014-10-31 2017-01-03 AppDynamics, Inc. Agent dynamic service
US9535666B2 (en) 2015-01-29 2017-01-03 AppDynamics, Inc. Dynamic agent delivery
WO2016183563A1 (en) 2015-05-14 2016-11-17 Walleye Software, LLC Historical data replay utilizing a computer system
US9934277B2 (en) 2015-05-19 2018-04-03 International Business Machines Corporation Data management system with stored procedures
US10216926B2 (en) * 2016-01-29 2019-02-26 Cisco Technology, Inc. Isolation of untrusted code in operating system without isolation capability
US10200876B2 (en) * 2017-01-17 2019-02-05 Argela Yazilim ve Bilisim Teknolojileri San. ve Tic. A.S. Method and system for a wireless access transmission network across intersecting electromagnetically shielded regions
US10002154B1 (en) 2017-08-24 2018-06-19 Illumon Llc Computer data system data source having an update propagation graph with feedback cyclicality

Citations (44)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5291597A (en) * 1988-10-24 1994-03-01 Ibm Corp Method to provide concurrent execution of distributed application programs by a host computer and an intelligent work station on an SNA network
US5613060A (en) * 1990-05-16 1997-03-18 International Business Machines Corporation Asynchronous resynchronization of a commit procedure
US5666514A (en) * 1994-07-01 1997-09-09 Board Of Trustees Of The Leland Stanford Junior University Cache memory containing extra status bits to indicate memory regions where logging of data should occur
US5845298A (en) * 1997-04-23 1998-12-01 Sun Microsystems, Inc. Write barrier system and method for trapping garbage collection page boundary crossing pointer stores
US5857210A (en) * 1997-06-26 1999-01-05 Sun Microsystems, Inc. Bounded-pause time garbage collection system and method including read and write barriers associated with an instance of a partially relocated object
US5873104A (en) * 1997-06-26 1999-02-16 Sun Microsystems, Inc. Bounded-pause time garbage collection system and method including write barrier associated with source and target instances of a partially relocated object
US5953736A (en) * 1997-04-23 1999-09-14 Sun Microsystems, Inc. Write barrier system and method including pointer-specific instruction variant replacement mechanism
US6003065A (en) * 1997-04-24 1999-12-14 Sun Microsystems, Inc. Method and system for distributed processing of applications on host and peripheral devices
US6014723A (en) * 1996-01-24 2000-01-11 Sun Microsystems, Inc. Processor with accelerated array access bounds checking
US6138143A (en) * 1999-01-28 2000-10-24 Genrad, Inc. Method and apparatus for asynchronous transaction processing
US6226734B1 (en) * 1998-06-10 2001-05-01 Compaq Computer Corporation Method and apparatus for processor migration from different processor states in a multi-processor computer system
US6243825B1 (en) * 1998-04-17 2001-06-05 Microsoft Corporation Method and system for transparently failing over a computer name in a server cluster
US6327594B1 (en) * 1999-01-29 2001-12-04 International Business Machines Corporation Methods for shared data management in a pervasive computing environment
US6330659B1 (en) * 1997-11-06 2001-12-11 Iready Corporation Hardware accelerator for an object-oriented programming language
US6385643B1 (en) * 1998-11-05 2002-05-07 Bea Systems, Inc. Clustered enterprise Java™ having a message passing kernel in a distributed processing system
US6408383B1 (en) * 2000-05-04 2002-06-18 Sun Microsystems, Inc. Array access boundary check by executing BNDCHK instruction with comparison specifiers
US6456893B1 (en) * 1996-11-26 2002-09-24 Shikoku Electric Power Company, Inc. Apparatus management system
US20020161816A1 (en) * 2001-04-30 2002-10-31 Sun Microsystems, Inc. Clean thread termination
US6496917B1 (en) * 2000-02-07 2002-12-17 Sun Microsystems, Inc. Method to reduce memory latencies by performing two levels of speculation
US6591278B1 (en) * 2000-03-03 2003-07-08 R-Objects, Inc. Project data management system and method
US6618737B2 (en) * 2000-03-09 2003-09-09 International Business Machines Corporation Speculative caching of individual fields in a distributed object system
US20030200526A1 (en) * 2002-04-17 2003-10-23 Sun Microsystems, Inc. Optimistic transaction compiler
US20030217092A1 (en) * 2002-05-16 2003-11-20 Sun Microsystems, Inc. Inter java virtual machine (JVM) resource locking mechanism
US20030226033A1 (en) * 2002-05-30 2003-12-04 Microsoft Corporation Peer assembly inspection
US6684297B2 (en) * 2001-04-11 2004-01-27 Sun Microsystems, Inc. Reverse directory for facilitating accesses involving a lower-level cache
US20040019670A1 (en) * 2002-07-25 2004-01-29 Sridatta Viswanath Pluggable semantic verification and validation of configuration data
US6701417B2 (en) * 2001-04-11 2004-03-02 Sun Microsystems, Inc. Method and apparatus for supporting multiple cache line invalidations per cycle
US6715128B1 (en) * 1998-11-27 2004-03-30 Hitachi, Ltd. Method for converting directory data, and program and device therefor
US6718457B2 (en) * 1998-12-03 2004-04-06 Sun Microsystems, Inc. Multiple-thread processor for threaded software applications
US6718839B2 (en) * 2001-06-26 2004-04-13 Sun Microsystems, Inc. Method and apparatus for facilitating speculative loads in a multiprocessor system
US6738977B1 (en) * 2000-05-31 2004-05-18 International Business Machines Corporation Class sharing between multiple virtual machines
US6799202B1 (en) * 1999-12-16 2004-09-28 Hachiro Kawaii Federated operating system for a server
US20040205377A1 (en) * 2003-03-28 2004-10-14 Nec Corporation Fault tolerant multi-node computing system for parallel-running a program under different environments
US6826757B2 (en) * 2000-04-18 2004-11-30 Sun Microsystems, Inc. Lock-free implementation of concurrent shared object with dynamic node allocation and distinguishing pointer value
US6862664B2 (en) * 2003-02-13 2005-03-01 Sun Microsystems, Inc. Method and apparatus for avoiding locks by speculatively executing critical sections
US6862693B2 (en) * 2001-04-13 2005-03-01 Sun Microsystems, Inc. Providing fault-tolerance by comparing addresses and data from redundant processors running in lock-step
US6892295B2 (en) * 2000-03-08 2005-05-10 Sun Microsystems, Inc. Processing architecture having an array bounds check capability
US6901491B2 (en) * 2001-10-22 2005-05-31 Sun Microsystems, Inc. Method and apparatus for integration of communication links with a remote direct memory access protocol
US6938130B2 (en) * 2003-02-13 2005-08-30 Sun Microsystems Inc. Method and apparatus for delaying interfering accesses from other threads during transactional program execution
US20060041885A1 (en) * 2002-11-08 2006-02-23 Stephane Broquere Method for managing virtual machines
US7013454B2 (en) * 1999-02-22 2006-03-14 Sun Microsystems, Inc. Thread suspension system and method using trapping instructions
US7058929B2 (en) * 1998-11-16 2006-06-06 Esmertec Ag Direct invocation of methods using class loader
US7222221B1 (en) * 2004-02-06 2007-05-22 Vmware, Inc. Maintaining coherency of derived data in a computer system
US7376078B1 (en) * 2004-03-24 2008-05-20 Juniper Networks, Inc. Selective replay of a state information within a computing device

Family Cites Families (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5999946A (en) * 1996-04-10 1999-12-07 Harris Corporation Databases in telecommunications
US6009271A (en) * 1996-10-28 1999-12-28 Bmc Software, Inc. Method of retrieving data from a relational database
US5920725A (en) * 1997-07-02 1999-07-06 Adaptivity Inc. Run-time object-synthesis and transparent client/server updating of distributed objects using a meta server of all object descriptors
US5987254A (en) * 1997-07-14 1999-11-16 Hewlett Packard Company System-wide memoization of array dependence information
US6016512A (en) * 1997-11-20 2000-01-18 Telcordia Technologies, Inc. Enhanced domain name service using a most frequently used domain names table and a validity code table
US6721740B1 (en) * 1998-05-29 2004-04-13 Sun Microsystems, Inc. Method and apparatus of performing active update notification
US6347312B1 (en) * 1998-11-05 2002-02-12 International Business Machines Corporation Lightweight directory access protocol (LDAP) directory server cache mechanism and method
US6725333B1 (en) * 1999-04-22 2004-04-20 International Business Machines Corporation System and method for managing cachable entities
US6636853B1 (en) * 1999-08-30 2003-10-21 Morphism, Llc Method and apparatus for representing and navigating search results
US6834290B1 (en) * 1999-11-15 2004-12-21 Quest Software, Inc. System and method for developing a cost-effective reorganization plan for data reorganization
US7065538B2 (en) * 2000-02-11 2006-06-20 Quest Software, Inc. System and method for reconciling transactions between a replication system and a recovered database
US6457020B1 (en) * 2000-03-20 2002-09-24 International Business Machines Corporation Query optimization using a multi-layered object cache
US6654766B1 (en) * 2000-04-04 2003-11-25 International Business Machines Corporation System and method for caching sets of objects
GB0024496D0 (en) * 2000-10-05 2000-11-22 Pettigrew Michael New compact disc case
US20020107835A1 (en) * 2001-02-08 2002-08-08 Coram Michael T. System and method for adaptive result set caching
US20020087798A1 (en) * 2000-11-15 2002-07-04 Vijayakumar Perincherry System and method for adaptive data caching
AU3047602A (en) * 2000-11-27 2002-06-03 Airclic Inc Scalable distributed database system and method for linking codes to internet information
US7162467B2 (en) * 2001-02-22 2007-01-09 Greenplum, Inc. Systems and methods for managing distributed database resources
US7424716B1 (en) * 2002-07-18 2008-09-09 Cisco Technology, Inc. Method for tracking an event through multiple module-specific files
US7159073B2 (en) * 2003-03-27 2007-01-02 Stmicroelectronics, Inc. Data storage and caching architecture
US20040193656A1 (en) * 2003-03-28 2004-09-30 Pizzo Michael J. Systems and methods for caching and invalidating database results and derived objects
US7395258B2 (en) * 2004-07-30 2008-07-01 International Business Machines Corporation System and method for adaptive database caching

Patent Citations (45)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5291597A (en) * 1988-10-24 1994-03-01 Ibm Corp Method to provide concurrent execution of distributed application programs by a host computer and an intelligent work station on an SNA network
US5613060A (en) * 1990-05-16 1997-03-18 International Business Machines Corporation Asynchronous resynchronization of a commit procedure
US5666514A (en) * 1994-07-01 1997-09-09 Board Of Trustees Of The Leland Stanford Junior University Cache memory containing extra status bits to indicate memory regions where logging of data should occur
US6014723A (en) * 1996-01-24 2000-01-11 Sun Microsystems, Inc. Processor with accelerated array access bounds checking
US6456893B1 (en) * 1996-11-26 2002-09-24 Shikoku Electric Power Company, Inc. Apparatus management system
US5953736A (en) * 1997-04-23 1999-09-14 Sun Microsystems, Inc. Write barrier system and method including pointer-specific instruction variant replacement mechanism
US5845298A (en) * 1997-04-23 1998-12-01 Sun Microsystems, Inc. Write barrier system and method for trapping garbage collection page boundary crossing pointer stores
US6003065A (en) * 1997-04-24 1999-12-14 Sun Microsystems, Inc. Method and system for distributed processing of applications on host and peripheral devices
US5857210A (en) * 1997-06-26 1999-01-05 Sun Microsystems, Inc. Bounded-pause time garbage collection system and method including read and write barriers associated with an instance of a partially relocated object
US5873104A (en) * 1997-06-26 1999-02-16 Sun Microsystems, Inc. Bounded-pause time garbage collection system and method including write barrier associated with source and target instances of a partially relocated object
US6330659B1 (en) * 1997-11-06 2001-12-11 Iready Corporation Hardware accelerator for an object-oriented programming language
US6243825B1 (en) * 1998-04-17 2001-06-05 Microsoft Corporation Method and system for transparently failing over a computer name in a server cluster
US6226734B1 (en) * 1998-06-10 2001-05-01 Compaq Computer Corporation Method and apparatus for processor migration from different processor states in a multi-processor computer system
US6385643B1 (en) * 1998-11-05 2002-05-07 Bea Systems, Inc. Clustered enterprise Java™ having a message passing kernel in a distributed processing system
US7058929B2 (en) * 1998-11-16 2006-06-06 Esmertec Ag Direct invocation of methods using class loader
US6715128B1 (en) * 1998-11-27 2004-03-30 Hitachi, Ltd. Method for converting directory data, and program and device therefor
US6718457B2 (en) * 1998-12-03 2004-04-06 Sun Microsystems, Inc. Multiple-thread processor for threaded software applications
US6138143A (en) * 1999-01-28 2000-10-24 Genrad, Inc. Method and apparatus for asynchronous transaction processing
US6327594B1 (en) * 1999-01-29 2001-12-04 International Business Machines Corporation Methods for shared data management in a pervasive computing environment
US7013454B2 (en) * 1999-02-22 2006-03-14 Sun Microsystems, Inc. Thread suspension system and method using trapping instructions
US6799202B1 (en) * 1999-12-16 2004-09-28 Hachiro Kawaii Federated operating system for a server
US6496917B1 (en) * 2000-02-07 2002-12-17 Sun Microsystems, Inc. Method to reduce memory latencies by performing two levels of speculation
US6591278B1 (en) * 2000-03-03 2003-07-08 R-Objects, Inc. Project data management system and method
US6892295B2 (en) * 2000-03-08 2005-05-10 Sun Microsystems, Inc. Processing architecture having an array bounds check capability
US6618737B2 (en) * 2000-03-09 2003-09-09 International Business Machines Corporation Speculative caching of individual fields in a distributed object system
US6826757B2 (en) * 2000-04-18 2004-11-30 Sun Microsystems, Inc. Lock-free implementation of concurrent shared object with dynamic node allocation and distinguishing pointer value
US6542990B1 (en) * 2000-05-04 2003-04-01 Sun Microsystems, Inc. Array access boundary check by executing BNDCHK instruction with comparison specifiers
US6408383B1 (en) * 2000-05-04 2002-06-18 Sun Microsystems, Inc. Array access boundary check by executing BNDCHK instruction with comparison specifiers
US6738977B1 (en) * 2000-05-31 2004-05-18 International Business Machines Corporation Class sharing between multiple virtual machines
US6701417B2 (en) * 2001-04-11 2004-03-02 Sun Microsystems, Inc. Method and apparatus for supporting multiple cache line invalidations per cycle
US6684297B2 (en) * 2001-04-11 2004-01-27 Sun Microsystems, Inc. Reverse directory for facilitating accesses involving a lower-level cache
US6862693B2 (en) * 2001-04-13 2005-03-01 Sun Microsystems, Inc. Providing fault-tolerance by comparing addresses and data from redundant processors running in lock-step
US20020161816A1 (en) * 2001-04-30 2002-10-31 Sun Microsystems, Inc. Clean thread termination
US6718839B2 (en) * 2001-06-26 2004-04-13 Sun Microsystems, Inc. Method and apparatus for facilitating speculative loads in a multiprocessor system
US6901491B2 (en) * 2001-10-22 2005-05-31 Sun Microsystems, Inc. Method and apparatus for integration of communication links with a remote direct memory access protocol
US20030200526A1 (en) * 2002-04-17 2003-10-23 Sun Microsystems, Inc. Optimistic transaction compiler
US20030217092A1 (en) * 2002-05-16 2003-11-20 Sun Microsystems, Inc. Inter java virtual machine (JVM) resource locking mechanism
US20030226033A1 (en) * 2002-05-30 2003-12-04 Microsoft Corporation Peer assembly inspection
US20040019670A1 (en) * 2002-07-25 2004-01-29 Sridatta Viswanath Pluggable semantic verification and validation of configuration data
US20060041885A1 (en) * 2002-11-08 2006-02-23 Stephane Broquere Method for managing virtual machines
US6862664B2 (en) * 2003-02-13 2005-03-01 Sun Microsystems, Inc. Method and apparatus for avoiding locks by speculatively executing critical sections
US6938130B2 (en) * 2003-02-13 2005-08-30 Sun Microsystems Inc. Method and apparatus for delaying interfering accesses from other threads during transactional program execution
US20040205377A1 (en) * 2003-03-28 2004-10-14 Nec Corporation Fault tolerant multi-node computing system for parallel-running a program under different environments
US7222221B1 (en) * 2004-02-06 2007-05-22 Vmware, Inc. Maintaining coherency of derived data in a computer system
US7376078B1 (en) * 2004-03-24 2008-05-20 Juniper Networks, Inc. Selective replay of a state information within a computing device

Cited By (67)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070169055A1 (en) * 2005-12-12 2007-07-19 Bernd Greifeneder Method and system for automated analysis of the performance of remote method invocations in multi-tier applications using bytecode instrumentation
US8402443B2 (en) * 2005-12-12 2013-03-19 dyna Trace software GmbH Method and system for automated analysis of the performance of remote method invocations in multi-tier applications using bytecode instrumentation
US7757215B1 (en) * 2006-04-11 2010-07-13 Oracle America, Inc. Dynamic fault injection during code-testing using a dynamic tracing framework
US9231858B1 (en) 2006-08-11 2016-01-05 Dynatrace Software Gmbh Completeness detection of monitored globally distributed synchronous and asynchronous transactions
US20080098309A1 (en) * 2006-10-24 2008-04-24 Microsoft Corporation Managing virtual machines and hosts by property
US8997048B1 (en) * 2007-02-14 2015-03-31 Oracle America, Inc. Method and apparatus for profiling a virtual machine
US20080243847A1 (en) * 2007-04-02 2008-10-02 Microsoft Corporation Separating central locking services from distributed data fulfillment services in a storage system
US20080243846A1 (en) * 2007-04-02 2008-10-02 Microsoft Corporation Locking semantics for a storage system based on file types
US8433693B2 (en) 2007-04-02 2013-04-30 Microsoft Corporation Locking semantics for a storage system based on file types
US8464225B2 (en) 2007-05-06 2013-06-11 Dynatrace Software Gmbh Method and system for adaptive, generic code instrumentation using run-time or load-time generated inheritance information for diagnosis and monitoring application performance and failure
US9047412B2 (en) 2007-05-06 2015-06-02 Dynatrace Corporation System and method for extracting instrumentation relevant inheritance relationships for a distributed, inheritance rule based instrumentation system
US20080276227A1 (en) * 2007-05-06 2008-11-06 Bernd Greifeneder Method and System for Adaptive, Generic Code Instrumentation using Run-time or Load-time generated Inheritance Information for Diagnosis and Monitoring Application Performance and Failure
US20100077078A1 (en) * 2007-06-22 2010-03-25 Fortisphere, Inc. Network traffic analysis using a dynamically updating ontological network description
US9588821B2 (en) 2007-06-22 2017-03-07 Red Hat, Inc. Automatic determination of required resource allocation of virtual machines
US9569330B2 (en) 2007-06-22 2017-02-14 Red Hat, Inc. Performing dependency analysis on nodes of a business application service group
US9727440B2 (en) 2007-06-22 2017-08-08 Red Hat, Inc. Automatic simulation of virtual machine performance
US20090182928A1 (en) * 2007-06-22 2009-07-16 Daniel Lee Becker Method and system for tracking a virtual machine
US9477572B2 (en) 2007-06-22 2016-10-25 Red Hat, Inc. Performing predictive modeling of virtual machine relationships
US20090183173A1 (en) * 2007-06-22 2009-07-16 Daniel Lee Becker Method and system for determining a host machine by a virtual machine
US10133607B2 (en) 2007-06-22 2018-11-20 Red Hat, Inc. Migration of network entities to a cloud infrastructure
US20080320499A1 (en) * 2007-06-22 2008-12-25 Suit John M Method and System for Direct Insertion of a Virtual Machine Driver
US8984504B2 (en) 2007-06-22 2015-03-17 Red Hat, Inc. Method and system for determining a host machine by a virtual machine
US8127290B2 (en) 2007-06-22 2012-02-28 Red Hat, Inc. Method and system for direct insertion of a virtual machine driver
US8949827B2 (en) 2007-06-22 2015-02-03 Red Hat, Inc. Tracking a virtual machine
US8566941B2 (en) 2007-06-22 2013-10-22 Red Hat, Inc. Method and system for cloaked observation and remediation of software attacks
US8191141B2 (en) 2007-06-22 2012-05-29 Red Hat, Inc. Method and system for cloaked observation and remediation of software attacks
US8539570B2 (en) * 2007-06-22 2013-09-17 Red Hat, Inc. Method for managing a virtual machine
US20080320592A1 (en) * 2007-06-22 2008-12-25 Suit John M Method and system for cloaked observation and remediation of software attacks
US20080320561A1 (en) * 2007-06-22 2008-12-25 Suit John M Method and System for Collaboration Involving Enterprise Nodes
US8429748B2 (en) 2007-06-22 2013-04-23 Red Hat, Inc. Network traffic analysis using a dynamically updating ontological network description
US8336108B2 (en) 2007-06-22 2012-12-18 Red Hat, Inc. Method and system for collaboration involving enterprise nodes
US20080320583A1 (en) * 2007-06-22 2008-12-25 Vipul Sharma Method for Managing a Virtual Machine
US9495152B2 (en) 2007-06-22 2016-11-15 Red Hat, Inc. Automatic baselining of business application service groups comprised of virtual machines
US8352911B2 (en) * 2007-11-21 2013-01-08 Teradata Us, Inc. Techniques for constructing and using run-time JAVA archives (JAR) for JAVA Stored Procedures (JSPS)
US20090132997A1 (en) * 2007-11-21 2009-05-21 John Douglas Frazier Techniques for constructing and using run-time java archives (jar) for java stored procedures (jsps)
US20090217276A1 (en) * 2008-02-27 2009-08-27 Brenner Larry B Method and apparatus for moving threads in a shared processor partitioning environment
US8245236B2 (en) 2008-02-27 2012-08-14 International Business Machines Corporation Lock based moving of threads in a shared processor partitioning environment
US9823992B2 (en) 2008-06-20 2017-11-21 Vmware, Inc. Decoupling dynamic program analysis from execution in virtual environments
US20090320011A1 (en) * 2008-06-20 2009-12-24 Vmware, Inc. Accelerating replayed program execution to support decoupled program analysis
US20090320010A1 (en) * 2008-06-20 2009-12-24 Vmware, Inc. Synchronous decoupled program analysis in virtual environments
US20090320009A1 (en) * 2008-06-20 2009-12-24 Vmware, Inc. Decoupling dynamic program analysis from execution in virtual environments
US9058420B2 (en) 2008-06-20 2015-06-16 Vmware, Inc. Synchronous decoupled program analysis in virtual environments
US8719800B2 (en) * 2008-06-20 2014-05-06 Vmware, Inc. Accelerating replayed program execution to support decoupled program analysis
US10255159B2 (en) 2008-06-20 2019-04-09 Vmware, Inc. Decoupling dynamic program analysis from execution in virtual environments
US8438404B2 (en) * 2008-09-30 2013-05-07 International Business Machines Corporation Main processing element for delegating virtualized control threads controlling clock speed and power consumption to groups of sub-processing elements in a system such that a group of sub-processing elements can be designated as pseudo main processing element
US20100082941A1 (en) * 2008-09-30 2010-04-01 Duvalsaint Karl J Delegated virtualization in a multi-core processor (mcp)
US9361160B2 (en) 2008-09-30 2016-06-07 International Business Machines Corporation Virtualization across physical partitions of a multi-core processor (MCP)
US20100131945A1 (en) * 2008-11-25 2010-05-27 Sap Ag System and method of implementing a concurrency profiler
US8645922B2 (en) * 2008-11-25 2014-02-04 Sap Ag System and method of implementing a concurrency profiler
US8863093B1 (en) * 2009-03-06 2014-10-14 Coverity, Inc. Load-time instrumentation of virtual machine program code
US20100332593A1 (en) * 2009-06-29 2010-12-30 Igor Barash Systems and methods for operating an anti-malware network on a cloud computing platform
US8533687B1 (en) 2009-11-30 2013-09-10 dynaTrade Software GmbH Methods and system for global real-time transaction tracing
US20120179778A1 (en) * 2010-01-22 2012-07-12 Brutesoft, Inc. Applying networking protocols to image file management
US8407531B2 (en) * 2010-02-26 2013-03-26 Bmc Software, Inc. Method of collecting and correlating locking data to determine ultimate holders in real time
US20110214024A1 (en) * 2010-02-26 2011-09-01 Bmc Software, Inc. Method of Collecting and Correlating Locking Data to Determine Ultimate Holders in Real Time
US8863108B2 (en) * 2010-11-23 2014-10-14 Red Hat, Inc. Finding out if software will run on an operating system without installing that software
US20120131538A1 (en) * 2010-11-23 2012-05-24 Kushal Das Mechanism for determining support criteria for shared libraries based on their priority levels
US8938706B2 (en) 2010-11-23 2015-01-20 Red Hat, Inc. Providing customized visualization of application binary interface/application programming interface-related information
US8887122B2 (en) 2010-11-23 2014-11-11 Red Hat, Inc. Find and track information of interface usage of software libraries by other software
US20120131564A1 (en) * 2010-11-23 2012-05-24 Kushal Das Process Of Finding Out If Software Will Run On An Operating System Without Installing That Software
US8776036B2 (en) * 2010-11-23 2014-07-08 Red Hat, Inc. Determining support criteria for shared libraries based on their priority levels
US9354960B2 (en) 2010-12-27 2016-05-31 Red Hat, Inc. Assigning virtual machines to business application service groups based on ranking of the virtual machines
WO2012118268A2 (en) * 2011-02-28 2012-09-07 ㈜지노게임즈 Multi-thread processing system using a multi-virtual machine, and method therefor
WO2012118268A3 (en) * 2011-02-28 2012-10-26 ㈜지노게임즈 Multi-thread processing system using a multi-virtual machine, and method therefor
US9274919B2 (en) 2011-04-29 2016-03-01 Dynatrace Software Gmbh Transaction tracing mechanism of distributed heterogenous transactions having instrumented byte code with constant memory consumption and independent of instrumented method call depth
US9811362B2 (en) 2011-04-29 2017-11-07 Dynatrace Software Gmbh Method and system for transaction controlled sampling of distributed heterogeneous transactions without source code modifications
US10163547B2 (en) * 2017-03-31 2018-12-25 Hitachi Metals, Ltd. Linear filler padded composite cable

Also Published As

Publication number Publication date
US20060271510A1 (en) 2006-11-30
US20060271575A1 (en) 2006-11-30
US20060271557A1 (en) 2006-11-30
US7716377B2 (en) 2010-05-11
US20060271542A1 (en) 2006-11-30
WO2006128062A3 (en) 2009-04-16
WO2006128062A2 (en) 2006-11-30
US20070088762A1 (en) 2007-04-19
US20060271930A1 (en) 2006-11-30
WO2006128112A2 (en) 2006-11-30
US20060271395A1 (en) 2006-11-30
US20060271511A1 (en) 2006-11-30
WO2006128112A3 (en) 2009-04-30
US20060271931A1 (en) 2006-11-30

Similar Documents

Publication Publication Date Title
Thomas Selecting Enterprise JavaBeans Technology
US6879995B1 (en) Application server message logging
US5835764A (en) Transaction processing system and method having a transactional subsystem integrated within a reduced kernel operating system
JP5214105B2 (en) Monitoring of virtual machine
Govil et al. Cellular Disco: Resource management using virtual clusters on shared-memory multiprocessors
CN100498699C (en) Sharing objects in runtime systems
Acharya et al. Sumatra: A language for resource-aware mobile programs
US5923833A (en) Restart and recovery of OMG-compliant transaction systems
Ghormley et al. GLUix: a global layer unix for a network of workstations
US8327351B2 (en) Application modification framework
Purtilo et al. Dynamic reconfiguration of distributed programs
CN1989488B (en) Robust sharing of runtime systems
US8478801B2 (en) Efficient reconstruction of virtual disk hierarchies across storage domains
Anderson et al. Designing a runtime system for volunteer computing
US8171491B2 (en) Object synchronization in shared object space
EP1212680B1 (en) Graceful distribution in application server load balancing
US6877111B2 (en) Method and apparatus for managing replicated and migration capable session state for a Java platform
Bernstein et al. Adapting microsoft SQL server for cloud computing
US20170257417A1 (en) Method, server and system for converging desktop application and web application
US20050144610A1 (en) Configuration manager in enterprise computing system
US5574903A (en) Method and apparatus for handling request regarding information stored in a file system
EP0735469B1 (en) System and method to control and administer distributed object servers using first class distributed objects
US6167430A (en) Multicomputer with distributed directory and operating system
CN100520721C (en) Method and apparatus for virtualizing window information
US8209699B2 (en) System and method for subunit operations in a database

Legal Events

Date Code Title Description
STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION