Chapter 20 Configuring Cache Cluster Settings : Configuring Caching Scheme, Multi-Engine, and Cluster Properties

Configuring Caching Scheme, Multi-Engine, and Cluster Properties
These properties enable you to select a provided caching scheme, and configure various aspects of the cache cluster. Some properties are not directly related to the cache cluster but are set at the level of a node or above. See Chapter 17, Understanding Cache OM and Multi-Engine Features for background information.
For rare situations requiring customization, contact TIBCO support for assistance.
Cluster Level Options, Summarized by Task
If using a backing store, specify whether to use a limited cache size or not, and set the size if so (if the default is not acceptable)
To set the path to Decision Manager external classes (rule function implementations) and select a class loader.
 
Cluster Level Option Details
If set to true the cache size is limited. Limited caches are used only when a backing store is used to store entries in excess of the limit.
Also see notes for java.property.be.engine.limited.cache.back.size.limit.
java.property.be.engine.limited.cache.back.size.limit
Specifies the size of the limited cache, in number of cache entries in each cache server (that is, each node where local storage is enabled).
Used only if be.engine.cluster.isCacheLimited is set to true and you want to use a non-default value.
If set to false, only one engine is active at any time (as in earlier versions). This is appropriate for In Memory OM and Persistence OM.
java.property.tangosol.coherence.distributed.backupcount
The backup count specifies the number of members of the distributed cache service that hold the backup data for each unit of storage in the cache. Recommended values are 0, 1, or 2.
Value of 0 means that in the case of abnormal termination, some portion of the data in the cache will be lost. Value of N means that if up to N cluster nodes terminate at once, the cache data will be preserved.
A backup count of 1 means one server plus one backup, that is, two cache servers (or storage enabled nodes if cache servers are not used).
To maintain the partitioned cache of size M, the total memory usage in the cluster does not depend on the number of cluster nodes and will be in the order of M*(N+1).
Specifies the minimum number of storage-enabled nodes that must be active in the cluster when the system starts up before the following occur:
The property does not affect the running of the deployed application after startup (though a message is written to the log file if the number of cache servers running falls below the number specified in this property).
java.property.tangosol.coherence.distributed.threads
As a guideline, set this value to the same number as there are processors available to the JVM. See Configuring Inference Agents—Engine Properties for details on the Agent.AgentGroupName.threadcount property.
be.engine.cluster.externalClasses.path
Specifies the filepath used by the cluster to load external rule classes created in Decision Manager to all BusinessEvents cluster nodes.
Set on one or more nodes as needed. Set this property in nodes where you also set be.engine.cluster.externalClasses.classLoader to true. Ensure these nodes can access the filepath.
Note: Cache OM is required for this feature.
Tip: Configure this property with the path to an RMS project deployment subdirectory to enable a seamless connection between the RMS approval process and the BusinessEvents loading process. This tip works for one RMS project only.
be.engine.cluster.externalClasses.classLoader
For related details, see notes for be.engine.cluster.externalClasses.path.
Note: Do not use nodes that contain only query agents.