Guide - Cache Engine Administration

Product Version

7.7

Product To Version

 
Status

final

1 Introduction

This document approaches the caching system of Intershop Commerce Management from the configuration perspective. It is addressed to administrators or DevOps who configure and maintain Intershop Commerce Management instances. This document does not describe the cache management framework. For details about the cache engine implementation, refer to Concept - Cache Management.

Info

Prior to Intershop version 7.7 the information provided in this document were part of the Administration and Configuration Guide that can be found in the Knowledge Base.

Note

All relevant setup options are to be configured in advance via dedicated deployment script files, before actually executing the deployment. So be aware that if you modify the Intershop Commerce Management configuration after it is deployed, all changes will be overridden with the settings specified for your deployment.

The Cache Engine provides a mechanism to manage and perform cache operations (clear, enable/disable, configure, etc.) for all Intershop Commerce Management caches on all application servers within the installation. The Cache Engine is implemented within the cartridge Cache. The Intershop Commerce Management administrator can monitor the cache efficiency and size, refresh the information, and change certain values for some caches.

Cache management via the Cache Engine is made possible by means of Java MBeans. MBeans are manageable resources in Java, and in Intershop Commerce Management MBeans are managed with JMX tools (see Guide - JMX and MBean Support). It should be noted that the cache engine handles a number of operations and thus, there is no UI specific to the Cache Engine in System Management or Commerce Management.

There are four cache groups that are managed via the cache engine:

  • ORMCache (persistent objects)
  • ObjectCache (Least Recently Used or LRU)
  • PageCache
  • SearchIndexReloadable

2 Cache Engine Messaging Settings

If there are several Intershop Commerce Management clusters in one subnet, a cluster may receive events from a foreign cluster if both clusters happen to be using the same multicast IP and port. In this case, you have to specify a unique multicast IP and port for each cluster in the cache.properties files, located in <IS.INSTANCE.SHARE>/system/config/cluster/.

The corresponding default settings (prefixed intershop.cacheengine.wrapped) are listed below.

If you intend to use other messaging systems than the default multicast, you must enable and adjust the corresponding intershop.cacheengine properties (see Guide - Messaging).

cache.properties
intershop.cacheengine.wrapped.messengerClass=
  com.intershop.beehive.messaging.internal.multicast.MulticastMessenger
intershop.cacheengine.wrapped.multicastAddress=239.1.2.3
intershop.cacheengine.wrapped.multicastPort=1234
#intershop.cacheengine.wrapped.multicastInterface=
#intershop.cacheengine.wrapped.multicastTimeToLive=
#intershop.cacheengine.wrapped.multicastReceiveBufferSize=1048576
intershop.cacheengine.wrapped.multicastListenerThreads=5
intershop.cacheengine.wrapped.multicastPacketSize=65000

3 Monitoring Cache Activity

To monitor cache activity, select the MBean tab in JVisual VM or JConsole (see Guide - JMX and MBean Support). Expand the com.intershop.enfinity tree structure. The resources (sets of MBeans) we are concerned with are CacheClearProcessor, CacheInformation and ClearableCaches. A description of each resource is listed in the table below.

Cache ResourceDescription
com.intershop.enfinity 
 CacheClearProcessorThis resource empties the objects within the ClearableCaches resource.
  BatchCacheClearCaches included here are cleared as a batch immediately or at a late time. For example, after a product upload has occurred.
  InstantCacheClearClears all Java VM caches included here based on conditions specified in the Intershop Commerce Management installation.
  ORMCacheSyncCacheClearClears local caches included here on the Java VM immediately based on conditions specified in the Intershop Commerce Management installation.
 CacheInformationThis resource displays cache attribute values (i.e., actual size, HitCount, Ratio, etc.). You can reset the monitor under the operations tab.
  ORMCacheDisplays data for Intershop Commerce Management classes, connections and transactions monitoring.
  PageCacheDisplays data for all sites within an Intershop Commerce Management instance.
  and morecustom caches
 CachesThis resource allows you to configure cache attributes (size, capacity, etc.), clear and enable/disable a cache.
  ORMCachesORM caches can be cleared here.
  ObjectCachesObject caches can be cleared here.
  PageCachesPage caches can be cleared here.
  SearchIndexesSearch index caches can be cleared here.
  SearchIndexReloadableDisplays data for content search within a given context (i.e., 'DE Specials' or 'US Specials').

Since the administrator must from time to time clear one or more caches, it is important that they are cleared in the following order:

(1) ORM

(2) ObjectCache

(3) SearchIndex

(4) PageCache

When clearing the page cache, it is necessary that the site has page caching enabled as well as keyword processing and text indexing selected. You can view/change the attributes for each site by entering System Management > Site Management > <your-site-name>-Site - Page Cache.

Disclaimer

The information provided in the Knowledge Base may not be applicable to all systems and situations. Intershop Communications will not be liable to any party for any direct or indirect damages resulting from the use of the Customer Support section of the Intershop Corporate Web site, including, without limitation, any lost profits, business interruption, loss of programs or other data on your information handling system.

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