Database caching utilizing asynchronous log-based replication

• US 8,712,961 B2
• Filed: 09/23/2011
• Issued: 04/29/2014
• Est. Priority Date: 09/23/2011
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Dwyer, Eamonn, Kavanagh, Daniel, Roche, Michael T.
• Primary Examiner(s): LE, HUNG D
• Application Number:
  US13/242,509
• Publication Number:
  US 20130080388A1
• Time in Patent Office: 949 Days
• Field of Search: None
• US Class Current: 707/634
• CPC Class Codes: G06F 16/24552 Database cache management

Abstract

A database table within a database to persist within a cache as a cached table can be identified. The database can be a relational database management system (RDBMS) or an object oriented database management system (OODBMS). The cache can be a database cache. Database transactions within can be logged within a log table and the cached table within the cache can be flagged as not cached during runtime. An asynchronous replication of the database table to the cached table can be performed. The replication can execute the database transactions within the log table upon the cached table. The cached table can be flagged as cached when the replication is completed.

Claims

1. A system comprising:

one or more processors;

one or more non-transitory memories for storing program instructions executable upon the one or more processors;

a query router, comprising at least a portion of the program instructions, within a database system and configured to route a database request to a database or a cache, wherein the database is at least one of a relational database management system (RDBMS) and an object oriented database management system (OODBMS), wherein the cache is a database cache;

a caching handler within the database system, comprising at least a portion of the program instructions, able to manage the synchronization state of tables replicated within the cache;

a pending statements table listing all cache tables and transactions written to the cache tables; and

a replication manager within the database system, comprising at least a portion of the program instructions, configured to asynchronously replicate a database table to a cache via metadata logging.

2. The system of claim 1, wherein the system is a component of a transparency layer within a database.

3. The system of claim 1, further comprising:

a cache metadata table populated by a cache configuration tool, wherein the cache metadata table lists the tables to cache and the state of the tables.

4. The system of claim 1, further comprising:

a replication list table referencing a list of tables undergoing an asynchronous replication from database to cache.

5. The system of claim 1, further comprising:

a checkpoint table undergoing asynchronous replication, tracking the state of synchronicity of a database table within the cache.

6. The system of claim 1, further comprising:

a checkpoint thread, a cache enablement thread, a connection handler thread.

7. A computer system comprising:

one or more processors, one or more computer-readable memories and one or more computer-readable, tangible storage devices;

program instructions, stored on at least one of the one or more storage devices for execution by at least one of the one or more processors via at least one of the one or more memories, to identify a database table within a database to persist within a cache as a cached table, wherein the database is at least one of a relational database management system (RDBMS) and an object oriented database management system (OODBMS), wherein the cache is a database cache;

program instructions, stored on at least one of the one or more storage devices for execution by at least one of the one or more processors via at least one of the one or more memories, to log a plurality of database transactions within a log table and flagging the cached table within the cache as not cached during runtime;

program instructions, stored on at least one of the one or more storage devices for execution by at least one of the one or more processors via at least one of the one or more memories, to perform an asynchronous replication of the database table to the cached table, wherein the replication executes the plurality of database transactions within the log table upon the cached table;

program instructions, stored on at least one of the one or more storage devices for execution by at least one of the one or more processors via at least one of the one or more memories, to flag the cached table as cached when the replication is completed;

a query router within the database configured to route a database request to a database or a cache, wherein the database is at least one of a relational database management system (RDBMS) and an object oriented database management system (OODBMS), wherein the cache is a database cache;

a caching handler able to manage a synchronization state of tables replicated within the cache with respect to the database;

a replication manager configured to asynchronously replicate any database table to the cache via metadata logging;

a pending statements table listing all cache tables and transactions written to the cache tables;

a cache metadata table populated by a cache configuration tool, wherein the cache metadata table lists the tables to cache and the state of the tables;

a replication list table referencing a list of tables undergoing an asynchronous replication from database to cache; and

a checkpoint table undergoing asynchronous replication, tracking the state of synchronicity of a database table within the cache.

8. A system comprising:

one or more processors;

one or more non-transitory memories for storing program instructions executable upon the one or more processors;

a query router, comprising at least a portion of the program instructions, within a database system and configured to route a database request to a database or a cache, wherein the database is at least one of a relational database management system (RDBMS) and an object oriented database management system (OODBMS), wherein the cache is a database cache;

a caching handler within the database system, comprising at least a portion of the program instructions, able to manage the synchronization state of tables replicated within the cache;

a cache metadata table populated by a cache configuration tool, wherein the cache metadata table lists the tables to cache and the state of the tables; and

a replication manager within the database system, comprising at least a portion of the program instructions, configured to asynchronously replicate a database table to a cache via metadata logging.

9. The system of claim 8, wherein the system is a component of a transparency layer within a database.

10. The system of claim 8, further comprising:

a pending statements table listing all cache tables and transactions written to the cache tables.

11. The system of claim 8, further comprising:

a replication list table referencing a list of tables undergoing an asynchronous replication from database to cache.

12. The system of claim 8, further comprising:

a checkpoint table undergoing asynchronous replication, tracking the state of synchronicity of a database table within the cache.

13. The system of claim 8, further comprising:

a checkpoint thread, a cache enablement thread, a connection handler thread.