KR0126089B1 - Distribute real-time data base management system - Google Patents

Abstract

A method for processing lock with relation to remote relation in diffusion real time DBMS is provided, which includes a first step (41) of determining whether an operator has indicated a processor to perform remote lock with EDML command, a second step (42-64) of processing global relation lock existing in the remote processor if the remote lock is determined not to have been indicated, and a third step (65-76) of performing lock for lor (local replicated) type of relations if the remote lock is determined to have been indicated, wherein remote simultaneity may be controlled by using simple operation words.

Description

Lock processing method for remote relation in distributed real-time database management system (DBMS)

1 is a distributed architecture diagram of an electronic switchboard database management system (DBMS) incorporating the teachings of the present invention.

2 is a block diagram and a message flow diagram between relevant blocks for performing a remote lock processing function implemented on an all-electronic switching system to which the present invention is applied.

3 is a general flow diagram of a remote lock processing function in an electronic switching center database management system (DBMS) according to the present invention.

* Description of the symbols for the main parts of the drawings *

10: switching subsystem 20: interconnection network subsystem

30: central control subsystem 32: operation and maintenance processor

The present invention relates to a method for processing a lock on a remote relation in a database management system (DBMS) of an electronic switching system, which is a distributed real-time system.

In a conventional exchange system, application programs that perform call processing, operation, maintenance, billing, and statistical functions each define and use necessary data in their own programs. In order to provide various functions in an exchange system consisting of multiple processors, applications need to access local data on their own processor as well as remote data on another processor.

In the electronic switchboard, a distributed real-time system, application programmers use only simple embedded data manipulation language (EDML) statements in their applications to access local and remote data. This makes it easy to write application programs and at the same time make it easy to manipulate data. Also, we use concurrency control method using lock technique to solve data inconsistency caused by multiple applications accessing data at the same time.

However, since only the concurrency control for access to local data is provided and the concurrency control for access to remote data is not provided, the consistency of remote data cannot be guaranteed, thereby reducing the reliability of the exchange system. A control function was required.

In addition, in the conventional general-purpose DBMS, after the user has previously connected to each relation or table unit, the user can lock only the connected relation or access the data of the relation. However, in a real-time distributed DBMS including an electronic switchboard, a function is required to perform a lock by designating a processor even without a connection to a relation existing in a remote processor.

Accordingly, the present invention supports concurrency control on remote data simultaneously accessed by application programs that perform call processing, operation, maintenance, billing, and statistical functions in an electronic switching system, which is a distributed real-time system, so that a plurality of applications can simultaneously Like concurrency control when accessing a local data, it provides a lock processing method that can guarantee the consistency of the data by accessing the remote data using only one lock / unlock EDML command. There is a purpose.

In order to achieve the above object, the present invention, in the method applied to a distributed architecture database management system (DBMS) having an operation and maintenance processor and a plurality of other processors performing the operation and maintenance functions, the operator EDML Determining whether a processor has indicated a processor to perform a remote lock; After performing the first step, if not indicated, a second step of processing a lock of a global relation existing in the remote processor, including a local relation existing in the processor on which the application program is executed; And a third step of performing a lock on relations of a lor (Local Replicated) type when a remote processor to perform a remote lock is indicated after performing the first step.

Hereinafter, with reference to the accompanying drawings will be described an embodiment according to the present invention;

1 is a structural diagram of a main memory DBMS having a distributed structure of an all-electronic exchange system.

This switchboard is equipped with ASS (Access Switching Subsystem) and INS (Intercon).

nection Network Subsystem (20), and Central Control Subsystem (CCS) (30)

Three subsystems.

ASS (10) is an access switching process (ASP) to perform a distributed call processing function

or) (11, 12) and the INS 20 performs INP (In to perform the centralized call processing function part.

It consists of terconnection Network Processor (NTP) and Number Translation Processor (NTP).

The CS 30 performs centralization functions related to operation and maintenance, and OMP (Operation and Main)

a tenance processor (32) and a man-machine processor (MMP) 31 are provided.

The electronic switchboard DBMS has its functions distributed according to the characteristics of the processors in order to manage the data distributed among the various processors as described above. The DBMS resides in main memory for real-time processing. It provides data processing functions, redundant data processing functions, data backup functions, data recovery functions, concurrency control functions, and transaction management functions.

Of the above processors, the OMS 32 DBMS has four blocks: DBBG (Data Base Backup Group), DBSG (Data Base Supporting Group), DBTG (Data Base Transaction Group) and DBKG (Data Base Kernel Group). The other processors, except MMP, have three blocks: DBKG, DBSG, and DBTG.

Here, the DBBG block requires disk access. Since the disk is mounted in the OMP 32, the DBBG block exists only in the OMP.

On the other hand, the MMP (31) performs a function that can receive input from the operator as well as the function of other processors except the OMP (32), so that in addition to the DBKG, DBSG, DBTG to interface with the operator terminal and the electronic switching system It has a DBQG (Data Base Query Group) block.

Looking at the function of each block of DBMS, DBSG performs the function of requesting DBKG to handle retrieval and change request of remote data in the application, and the communication function between DBMS for remote data processing. It performs concurrency control function, DBKG performs the function to search and change the data in the database according to the retrieval and change of the data that the processing request comes in. DBBG actually performs the function when the data requesting the change requires disk backup. It backs up the database on disk and restores the database when the system restarts. Finally, DBQG performs on-line query processing.

2 is a structural diagram showing a configuration and message flow between related blocks for performing a remote lock processing function implemented on an all-electronic switching system, which is a distributed real-time system.

There are two cases where you can perform concurrency control on a remote processor using an EDML lock instruction within an application.

One is defined globally so that the relation exists only on one processor of the whole system and is accessible to other processors on which the application is running, so that the DBMS does not need to point to the processor where the relation exists in the EDML instruction. This is the case of a lock that can be retrieved and executed on a suitable processor. The other is a lock with respect to lor (local replicated) relations that exist in different processors with the same name and same schema, but with different data. This is the case when you indicate the processor to actually perform.

The lock on the local relation is included in the case of the lock on the global relation. The two cases differ in whether they indicate the processor that actually locks the relation in the form of EDML lock instruction to be executed, and the DBMS separately handles these two cases.

First, the lock processing method of the global relation existing in the remote processor including the local relation is as follows.

When EDML is used to lock relations in an application, the database library (DBLIB), which is the interface between the application and the DBMS, requires DBKG to access the database. DBKG then searches the directory and dictionary containing information about relations in the database and checks whether a relation exists on its processor that requires a lock. If the relation is a local relation that exists in its own processor, the lock is performed. In the case of a global type relation that does not exist in its own processor, the processor in which the relation exists can be executed by a remote processor. Writes a message with only information about the and locks and sends it to the database library (DBLIB). The database library DBLIB receives the lock result of the local relations and the lock information of the remote global type relation, and transmits the lock information to the DBSG of the processor where the remote relation exists when the lock message of the remote relation exists. The DBSG requests the DBKG to perform the lock according to the received remote lock information. The DBKG performs the lock only if the relation requesting the lock is a local relation that exists on its processor. Otherwise, the DBKG returns the lock to the original state and returns the result to the DBSG. DBSG sends the result from DBKG to the database library (DBLIB) of the processor on which the application is running. The database library (DBLIB) notifies the application if the result of remote lock execution is successful. On the other hand, if it isn't successful, it returns all the locks done by its processor and informs the application of the results.

In order to perform locks on relations of type Lor, one must point to the processor on which the lock is actually executed in the EDML instruction in the application. The database library (DBLIB) sends a message of only the information about the lock directly to the DBSG of the remote processor indicated by the command. The DBSG of the remote processor asks the DBKG to perform the lock according to the received remote lock information. DBKG performs the lock only if the relations that are requested to make the lock are all local relations that exist in its processor. Otherwise, DBKG returns the locks that were determined to be in error and return them as they were. Tell DBSG When the DBSG passes the result to the database library (DBLIB) of the processor on which the application is running, the database library (DBLIB) finally informs the application of the results of the remote lock execution.

3 is an overall flowchart of the remote lock processing function in the electronic switching center DBMS which is a distributed real-time system.

The EDML instruction is divided into the case of indicating the processor to perform the remote lock and the case of not pointing (41). First, the method of processing the lock of the global relation in the remote processor, including the local relation in the processor where the application is executed without pointing to the processor, is as follows. When an application uses EDML to lock a database, the database library (DBLIB) requires DBKG to access the data (42). The DBKG, 43 requested to perform a lock on the relations (43), searches the directory and dictionaries (44) to find out whether the requested relation exists on its processor (45). If the position of the relation is its processor, the lock on the relation is performed (46). For a relation of a global type that does not exist in its processor, the processor identifies the processor in which the relation is located (47) and writes a message with only the information (48). After the DBKG completes the appropriate operation for each of the requested relations, it sends a message with the result of performing the local relation lock and the created remote lock information to the database library (DBLIB) (49). When locking only local relations, the database library (DBLIB) tells the application what to do. On the other hand, if the message of the remote global relation exists, the database library (DBLIB) transmits a lock message to the DBSG of the processor in which the remote relation exists (51). The DBSG at the remote processor of the application receives the remote lock information (52), passes it back to the DBKG, and requests to perform the lock (53). The DBKG receives this (54) and searches (55) directories and dictionaries. The lock is performed only if the relation requesting to lock is the local relation existing on its processor (56), otherwise it is determined to be an error and, if there are already performed locks, they are returned to their original state. Reduce (58). After the execution of the DBKG, the remote lock result is transmitted (59), and the DBSG receives the execution result (60) and transmits the result to the database library (DBLIB) of the processor where the application is being executed (61). The database library (DBLIB) receives the result of the remote lock execution (62) and informs the application of the result if successful. On the other hand, if it is not successful, it returns 64 all the locks done by its processor and informs the application of the result.

The flow of performing a lock on relations of lor type pointed out by the remote processor to perform the lock is as follows. The database library (DBLIB) receives only a message about the lock from the application and sends it to the DBSG of the remote processor indicated by the command (65). The DBSG of the remote processor passes the received remote lock information 66 to the DBKG and requests to perform the lock (67). The DBKG that receives the request to perform a remote lock (68) searches the directory and the dictionary dictionary (69) and performs the lock only if all of the relations that request to lock are local relations (70) on their processor. (71) Otherwise, the locks determined to be in error are returned to their original state (72) and the result is transferred to the requesting DBSG (73). The DBSG transfers the received (74) result to the database library (DBLIB) of the processor on which the application is running (75). The database library (DBLIB) that receives the remote lock result informs the application of the remote lock execution result.

The present invention as described above operates in a distributed real-time system all-electronic exchange system has the following effects.

First, in order to perform remote concurrency control in an application program that performs call processing, operation, maintenance, billing, and statistics functions in a distributed real-time system, the application program can be easily and concisely used. It was able to improve the productivity of the program.

Second, by supporting concurrency control for remote data, the reliability of the exchange could be improved by resolving data inconsistencies caused by multiple applications accessing the data at the same time, including remote access on one processor.

Claims (3)

In a method applied to a distributed architecture database management system (DBMS) having an operation and maintenance processor 32 that performs an operation and maintenance function and a plurality of other processors, an operator may perform remote lock on EDML instructions. A first step 41 of determining whether a processor has been pointed out; After performing the first step 41, if not indicated, the second step 42 to process the locking of the global relation existing in the remote processor, including the local relation existing in the processor on which the application program is executed. 64); And a third step (65 to 76) of performing a lock on relations of lor (Local Replicated) type when the remote processor to perform the remote lock is indicated after performing the first step 41. A lock processing method for a remote relation in a distributed real-time database management system (DBMS) characterized by the above-mentioned. The method of claim 1, wherein the second steps 42 to 64 are performed by the DBKG, which is requested to perform a lock on relations when the DBLIB requests data access from the DBKG. A fourth step (42 to 45) for determining whether the existing relation exists in the own processor; After performing the fourth step (42 to 45), if the location of the requested relation is its processor, the lock is performed and the local lock result is transmitted to the database library (DBLIB), and then the existence of the remote lock is determined. For the global type relation that does not exist in the processor, the fifth step is to find out the processor where the relation is located, create a message with only the lock information, pass it to the database library (DBLIB), and then determine the existence of the remote lock. 46 to 50); After performing the fifth step (46 to 50), if the lock is performed only on the local relations, the database library (DBLIB) delivers the command execution result to the application program, and a message of a remote global (glpbal) relation exists. The database library (DBLIB) then sends a lock message to the DBSG of the processor where the remote relation exists, and the DBSG at the remote processor of the application receives the remote lock information and passes it back to the DBKG to request that the lock be performed. Step 6 (51 to 56), after receiving the request to perform the lock, searching the directory and the dictionary for determining whether a relation in which the request comes in to lock is present in its processor; After performing the sixth step (51 to 56), if the local relation DBSG performs a remote lock and transmits the remote lock result, the DBSG receives the remote lock execution result to the database library (DBLIB) of the processor that the application program is running The database library (DBLIB) receives the result of performing the remote lock to determine whether the remote lock was successful, and if it is not a local relation, it judges it as an error and returns the original lock if there are already performed locks. DBSG receives the result of performing the remote lock and sends it to the database library (DBLIB) of the processor where the application is running, and the database library (DBLIB) receives the result of the remote lock to determine whether the remote lock was successful. Seventh step (57 to 63) to perform; And performing the seventh step (57 to 63), if the remote lock is successful, and notifies the application of the result, if not successful, after reducing all the locks performed by the processor, the eighth to inform the application. A lock processing method for a remote relation in a distributed real-time database management system (DBMS), characterized in that it comprises a step (64). The method of claim 1, wherein the third steps (65 to 76), the database library (DBLIB) receives a message only from the information about the lock from the application program and transmits the message to the DBSG of the remote processor indicated in the command and the remote processor DBSG sends the received remote lock information to the DBKG to request that the lock be performed, and upon receiving the request to perform the remote lock, the DBKG retrieves the directory and the dictionary of arguments, and all the relations that are requested to make the lock are sent to their processor. A fourth step (65 to 70) for determining whether there is; After performing the fourth step (65 to 70), if it is a local relation, the lock is performed and the result is transmitted to the requesting DBSG. The DBSG transmits the received result to the processor's database library (DBLIB). Receiving a remote lock result, the database library (DBLIB) may include a fifth step (71, 73 to 76) informing the application program of the result of performing the remote lock; And after performing the fourth step (65 to 70), if it is not a local relation, the locks determined as an error are returned to their original state, and the result is transferred to the requesting DBSG, and the DBSG executes the received result. The database library DBLIB, which is transmitted to the database library DBLIB of the processor being processed and receives the remote lock result, has a sixth step (72 to 76) for informing the application program of the result of performing the remote lock. A lock processing method for a remote relation in a distributed real-time database management system (DBMS).