Configuring HCL Commerce data cache

The HCL Commerce data cache is enabled by default. You can configure the cache by using either the command caching or DistributedMap objects configuration methods. For the best performance, use DistributedMap object cache configuration. Command caching configuration is provided for compatibility with earlier versions only.

If you use command caching, you can choose which data to cache. You can fine-tune the configuration by changing the <cache-entry> element attributes, such as <priority>, <timeout>, and <inactivity>. For more information, see cachespec.xml.

The HCL Commerce data cache can be configured to use DistributedMap object caches, by defining specially named object caches in the cacheinstances.properties file.

Some DistributedMap object caches are defined automatically during installation. To view these object caches, open the WebSphere Application Server Integrated Solutions Console, and on the left menu, click Resources > Cache instances > Object cache instances.

Procedure

Command caching
1. Open the sample cache configuration file cachespec.xml in the following directory:
  - WCDE_installdir\samples\dynacache\
2. Copy <cache-entry> elements from the sample cache configuration file to the cachespec.xml file found in the following directory:
  - workspace_dir\Stores\WebContent\WEB-INF\
If you already have cache entry tags that are defined in your Stores cachespec.xml file, you might need to measure throughput, CPU usage, and memory usage, and adjust priority, timeout, and inactivity tags to obtain the best performance.
Object caching in specified DistributedMap instances causes each type of data to be cached in its corresponding DistributedMap object.
When you use this method, the cachespec.xml configurations are not used for the kinds of data that has a corresponding DistributedMap defined. You cannot fine-tune the priority, timeout, or inactivity settings by using the cachespec.xml configuration file. However, you can specify other DistributedMap attributes, such as the maximum number of cache entries to be used by each DistributedMap. For more information about the cacheinstances.properties file format, see Using the DistributedMap and DistributedObjectCache interfaces for the dynamic cache.
There are two ways you can define DistributedMap objects:
1. Define DistributedMap objects with the default JNDI names in the cacheinstances.properties file in the following directory:
  - WCDE_installdir\samples\dynacache\
  You can copy and paste selected contents of the samples\dynacache\cacheinstances.properties file into your custom cacheinstances.properties file in the Stores.war\WEB-INF\classes directory.
2. Use the WebSphere Application Server Integrated Solutions Console. From the left menu, click Resources > Cache instances > Object cache instances.
In a clustered environment, make sure that a replication domain is defined, and at least the services/cache/WCSessionDistributedMapCache object cache is defined. All object caches must enable cache replication (notShared replicationType 1) to allow invalidation IDs to be sent to all nodes in the replication domain. Otherwise, invalidation IDs are not sent to all nodes in the replication domain, resulting in incorrect results due to stale data in some cache instances. Make sure to specify the replication domain and a valid replication type. The "not shared" replication type is recommended.

Object cache instances that are defined in the cacheinstances.properties files set the corresponding properties for each cache instance.


Property Name	Value
cache.instance.n.cacheSize	Start with the size in the sample cacheinstances.properties file
cache.instance.n.enableDiskOffload	Start with false. Measure the performance effect before you change this setting. Specify true for cache instances that contain long lived data applicable to many shoppers. However, for both performance and privacy concerns, do not offload user data to the disk.
cache.instance.n.flushToDiskOnStop	Start with false
cache.instance.n.disableDependencyId	false
cache.instance.n.useListenerContext	false
cache.instance.n.filterLRUInvalidation	true
cache.instance.n.filterTimeOutInvalidation	true
cache.instance.n.filterInactivityInvalidation	true
cache.instance.n.disableTemplatesSupport	true
cache.instance.n.ignoreValueInInvalidationEvent	true
cache.instance.n.useServerClassLoader	true

Configure an object cache to use the WebSphere eXtreme Scale service provider.

Object cache instances that are defined in the cacheinstances.properties files set the corresponding properties for each cache instance.


Property Name	Value
cache.instance.n.enableDiskOffload	false
cache.instance.n.flushToDiskOnStop	false
cache.instance.n.disableDependencyId	false
cache.instance.n.useListenerContext	false
cache.instance.n.enableCacheReplication	true
cache.instance.n.replicationType	1
cache.instance.n.filterLRUInvalidation	true
cache.instance.n.filterTimeOutInvalidation	true
cache.instance.n.filterInactivityInvalidation	true
cache.instance.n.disableTemplatesSupport	true
cache.instance.n.ignoreValueInInvalidationEvent	true
cache.instance.n.useServerClassLoader	true
cache.instance.n.cacheProviderName	com.ibm.ws.objectgrid.dynacache.CacheProviderImpl
cache.instance.n.com.ibm.websphere.xs.dynacache.topology	remote

Note:

The custom property cache.instance.n.com.ibm.websphere.xs.dynacache.topology is only required for eXtreme Scale below version 8.6.
Using WebSphere eXtreme Scale 8.6, the custom property cache.instance.n.com.ibm.websphere.xs.dynacache.disable_recursive_invalidate must not be used. If you use this custom property, excessive amounts of warning messages are logged to the SystemOut.log log file. For more information about this issue, see APAR #.
The default cache monitor cannot view the contents of the object cache instances. To view the content of an object cache instance, install IBM Extended Cache Monitor for IBM WebSphere Application Server. For more information about this monitor, or to download it, see IBM developerWorks documentation: