JPH05128070A - Remote cache control device and its method - Google Patents

Abstract

PURPOSE:To speed up data reading response by caching the data of a remote system in a local system in the case of accessing a data base in a network system. CONSTITUTION:The local system 2 is provided with a remote cache control part 6 and a cache memory 7 and the remote system 1 is provided with a remote data base managing part 5 and a data base management 4 for managing a data base 11. These remote and local systems 1, 2 are mutually connected through a communication control part 81, a communication line network 10 and a communication control part 82 so as to attain data communication. When data reading requests are outputted from plural operation programs 3 in the system 2 to the data base 11, cache control is executed by the managing part 5 and the control part 6 based upon an I/O mode in/from the data base 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a remote cache control device and method as a database access method for a server / client type horizontal distributed network.

[0002]

2. Description of the Related Art Conventionally, in database access in a horizontally distributed network, a database in a remote system is accessed in response to a database access request from a business program on a local system.

[0003]

However, in the conventional technique, data communication is always performed between the remote system and the local system for each database access request from the business program to the remote system.

Therefore, when the database in the remote system is a non-shared type or a reference type and data is repeatedly used, unnecessary access is performed and the data access speed tends to decrease. It was

It is an object of the present invention to provide a remote cache control apparatus and method which eliminates the above drawbacks of the prior art and enables faster database access.

[0006]

A first solution of the present invention for solving the above-mentioned problems is a database management for centrally managing a system database and a communication control unit for performing data communication via a communication network. Of a local system including a remote system including a remote system, at least one business program that performs data processing using data in the database, and a communication control unit that performs data communication via the communication network. A remote cache control device comprising: in the local system, a cache memory that caches read data from the database and stores the data; and a remote cache control unit that controls use of the cache memory. From the business program of the local system to And had not a group in the mode specified in accessing the database, characterized in that it comprises a remote database management unit for commanding the license of the cache memory to the remote cache controller.

A second solution of the present invention for solving the above problem is a remote system comprising a database management for centrally managing a system database and a communication control section for performing data communication via a communication circuit network. A plurality of local systems including at least one business program that performs data processing using the data in the database and a communication control unit that performs data communication via the communication network are connected by the communication network. A remote cache control device for a horizontally distributed network system comprising: a cache memory for storing read data from the database in a cache inside each of the local systems; and a remote cache for controlling the use of the cache memory. And a control unit in the remote system Said have not a group in the mode specified when accessing the database from a local system operations program, characterized in that it comprises a remote database management unit for commanding the license of the cache memory to the remote cache controller.

A third solution of the present invention for solving the above problem is a remote system comprising a database management for centrally managing a system database and a communication control section for performing data communication via a communication circuit network. A plurality of local systems including at least one business program that performs data processing using the data in the database and a communication control unit that performs data communication via the communication network are connected by the communication network. A remote cache control device for a horizontal distributed network system, comprising: a cache memory step of storing read data from the database in each of the local systems, and a remote cache control for controlling use of the cache memory. And the remote system A remote database management step for instructing the remote cache control step whether or not to operate the cache memory step based on a mode designation when accessing the database from a business program of the local system in the system. It is characterized by

[0009]

The remote cache control function of the present invention is a communication for performing communication between a remote cache control unit for performing caching processing and remote access processing in response to a database access request from a business program on a local system, a cache memory and a remote system. The remote control system has a control unit and a database management unit. On the remote system, a communication control unit for performing database management and communication with the local system, and access to the database management and a cache on / off for the remote cache control unit according to a request from the local system. A remote database management unit for turning off is provided.

[0010]

The present invention will be described below with reference to the drawings.

FIG. 1 is a configuration block diagram of the present invention. The remote system 1 includes a database management 4 including a database 11, a remote database management unit 5, and a communication control unit 81. The local system 2 also includes a remote cache control unit 6, a cache memory 7, and a communication control unit 82, and a plurality of business programs such as a business program 3 stored in a main storage device or an auxiliary storage device of the local system 2. Therefore, these business programs are simultaneously operated by time sharing or the like. The remote system 1 and the local system 2 are connected by a communication circuit network 10 such as a communication line or a local area network.

In order to access the database 11 of the remote system 1 by the business program 3 of the local system 2, an open / close request for declaring the start / end of use of the database 4 and a read / access request for accessing the actual data. A write request or the like is made to the remote system 1. At the time of this open request, it is necessary to specify the input / output mode in order to perform the sharing / exclusive control of the database 11, and three modes of input only, output only or input / output only are specified.

For an open request from the business program 3 of the local system 2 to the database 11 of the remote system 1, a command is sent from the remote cache control unit 6 of the local system 2 to the communication control unit 81, and the communication control unit 82 sends a command to the communication circuit. A command is sent to the communication control unit 81 via the network 10, and the communication control unit 81 further notifies the remote database management unit 5 of an open request for the database 11 from the local system 2.

The remote database management unit 5 requests the database management 4 to open the database 11, and also performs the following processing according to the combination of the usage status immediately before the database 11 and the input / output mode designation from the business program 3. ..

(1) The database 11 is unused and
When the open request from the business program 3 is the first, and the mode designation of the open request is only the input mode, the remote database management unit 5 performs the remote cache control via the communication control units 81 and 82. The remote cache control unit 6 is notified that the cache cannot be used in any mode other than the input mode.
To notify. Here, control of cache use means that, in response to a read request of the database 11 from the business program 3, if corresponding data exists in the cache memory 7, the remote cache control unit 6 notifies the business program 3 of the data, If the corresponding data does not exist in the cache memory 7, the database management 4 is accessed via the communication controls 81 and 82 and the remote database management unit 5, the corresponding data is notified to the business program 3 and the data is expanded in the cache memory 7. It represents the action to be taken. On the contrary, the cancellation of the cache control means the invalid processing of the valid data existing in the cache memory 7 and the operation of always accessing the database management 4 in response to the read request from the business program 3 thereafter. .. (2) When the database 11 is already used by another business program of the local system 2, the mode designation of all the business programs using the database 11 including the business program 3 that has made the open request is the input mode. If so, the cache is enabled and the remote cache controller 6
To notify. If both the business program 3 and the other business program that is using the database 11 are in other than the input mode, the remote cache control unit 6 is notified that the cache cannot be used. (3) When all the other business programs that are using the database 11 are in the input mode, and conversely, only the mode designation of the business program 3 is other than the input mode, the cache unusability is notified to the remote cache control unit 6. At the same time, it notifies the remote cache control unit 6 of the local system that the cache cannot be used so that another business program of the local system 2 that is using the database 11 does not use the cache memory 7 when a data read request for the database 11 is made.
(4) When the business program 3 issues a close request, the remote cache control unit 6 and the communication control units 81 and 8
It is notified to the remote database management unit 5 via 2. The remote database management unit 5 requests the database management 4 to close the database 11, and when the input / output mode for the database 11 of the business program 3 is the input mode, the database 1
If 1 is being used by another business program of the local system 2 and all the business programs specify the input mode, the remote cache control unit 6 of the local system 2 is notified that the cache is enabled. To do.

As a response to the open request to the remote database management unit 5, the remote cache control unit 6 receives a cache availability notification or receives a cache availability notification asynchronously notified from the remote database management unit 5. Then, the remote cache control unit 6 performs cache use control with respect to subsequent database read requests of business programs accessing the database 11. Further, when the cache unavailability is asynchronously notified from the remote database management unit 5, the cache use control is released immediately. Here, in the two computer systems connected by the communication circuit network 10, the system in which the business program 3 operates is the local system 2 and the system in which the database 11 exists is the remote system 1, but two or more computers are used. Even in a network in which is connected by a communication circuit network, bidirectional database access can be performed by the above-mentioned configuration, and in addition, a plurality of business programs exist in each local system consisting of those computers, Data access from those business programs to the database 11 of the remote system 1 simultaneously from a plurality of local systems 2 is performed.
The remote database management unit 5 can also be controlled.

[0017]

As described above, according to the present invention, the database contents of the remote system are cached in the cache memory 7 provided on the local system, so that the number of accesses to the remote system is reduced and the data read response is improved. Has the effect of

[Brief description of drawings]

FIG. 1 is a configuration block diagram of an embodiment of the present invention.

[Explanation of symbols]

 1 remote system 2 local system 3 business program 4 database 5 remote database management unit 6 remote cache control unit 7 cache memory 81 communication control unit 82 communication control unit

Claims (3)

[Claims] 1. A remote system comprising a database management for centrally managing a system database and a communication control unit for performing data communication via a communication circuit network, and at least one for performing data processing using data in the database. A remote cache control device for a network comprising one business program, and a local system including a communication control unit for performing data communication via the communication circuit network, wherein read data from the database is stored in the local system. A cache memory for storing in a cache and a remote cache control unit for controlling use of the cache memory are provided, and the remote system is based on a mode designation when accessing the database from a business program of the local system. Remove the above Remote cache controller, characterized in that it comprises a remote database management unit for commanding the license of the cache memory to the remote cache controller. 2. A remote system including a database management for centrally managing a system database and a communication control unit for performing data communication via a communication circuit network, and at least one for performing data processing using data in the database. A remote cache control device for a horizontal distributed network system, comprising a plurality of business programs, and a local system having a communication control unit for performing data communication via the communication circuit network, connected by a plurality of the communication circuit networks, Inside each of the local systems, a cache memory that caches and stores read data from the database and a remote cache control unit that controls use of the cache memory are provided, and the local system is provided in the remote system. From the business program of And had not a group in the mode specified when accessing the database, the remote cache controller, characterized in that it comprises a remote database management unit for commanding the license of the cache memory to the remote cache controller. 3. A remote system comprising a database management for centrally managing a system database and a communication control section for performing data communication via a communication circuit network, and at least one for performing data processing using the data of the database. A remote cache control method for a horizontal distributed network system, comprising a plurality of business programs and a local system having a communication control unit for performing data communication via the communication circuit network, which is connected by a plurality of the communication circuit networks. Each of the local systems includes a cache memory step of caching read data from the database and storing the read data, and a remote cache control step of controlling use of the cache memory. Program or Said have not a group in the mode specified when accessing the database, the remote cache control method characterized by comprising a remote database management step for instructing whether or not to operate the cache memory step to said remote cache control step of.