As illustrated in the figure on this page, the Persistence object management option persists a snapshot of the working memory for each inference agent (rule session) in the deployed system. The data for each inference agent is persisted to a data store at specified intervals.
The persistence data store is provided and managed by BusinessEvents.
Persistence-based object management provides data recovery in the case of a complete system failure. When the system comes up after a system failure, BusinessEvents restores the working memory (or memories) to the last checkpoint state. It also receives all of the previously unacknowledged messages (see
Message Acknowledgment Timing for Each Object Management Type).
Data in memory at time of failure and not yet written to disk is lost.
Use of the Persistence option affects performance, due to the disk writes required. BusinessEvents provides parameters — checkpoint interval and property cache size — to help you tune performance. You can also determine how many objects to keep in the data cache, in order to manage JVM memory usage for the application for better performance.
Fault tolerance features for Persistence object management are not provided by BusinessEvents. You can, however, implement a custom fault tolerance solution using TIBCO Rendezvous and TIBCO Hawk or third-party fault-tolerance tools. For example, you could set up two servers that each point to the same persistence data store, and you could write rules in your fault-tolerance tool to detect failure and take appropriate steps (for example, removing any lock files) when failing over to the secondary server.
If you decide to change to a Cache OM option, follow procedures in TIBCO BusinessEvents Installation, to migrate data. You must of course configure the other features of Cache OM as well.