Aggregating content store

The Aggregating content store contains a primary store and a set of secondary stores. The order in which the stores appear in the list of participating stores is important. The first store in the list is known as the primary store. Content can be read from any of the stores, as if it were a single store. When the replicator goes to fetch content, the stores are searched from first to last. The stores should therefore, be arranged in order of speed.

For example, if you have a fast (and expensive) local disk, you can use this as your primary store for best performance. The old infrequently used files may be stored on lower cost, slower storage.

When replication is disabled, content is written to the primary store only. The other stores are used to retrieve content and the primary store is not updated with the content.

Example configuration for tiered storage

The following configuration defines an additional tiered storage solution. The default content store is not changed. An additional set of secondary stores is defined (tier1, tier2 and tier3). As content ages (old infrequently used files), it can be moved to lower tiers. If the tiered storage is slow, a Caching content store can be placed in front.

<?xml version='1.0' encoding='UTF-8'?>
<!DOCTYPE beans PUBLIC '-//SPRING//DTD BEAN//EN' 'http://www.springframework.org/dtd/spring-beans.dtd'>

<!-- This file enables an aggregating content store. It should be placed in shared/classes/alfresco/extension -->

<beans>

  <bean id="defaultContentStore" class="org.alfresco.repo.content.filestore.FileContentStore">
      <constructor-arg>
         <value>${dir.contentstore}</value>
      </constructor-arg>
      
      <!-- Uncomment the property below to add content filesize limit.
      <property name="contentLimitProvider" ref="defaultContentLimitProvider"/>
      -->
  </bean>


  <bean id="tier1ContentStore" class="org.alfresco.repo.content.filestore.FileContentStore">
      <constructor-arg>
         <value>${dir.contentstore1}</value>
      </constructor-arg>
      
      <!-- Uncomment the property below to add content filesize limit.
      <property name="contentLimitProvider" ref="defaultContentLimitProvider"/>
      -->
  </bean>

  <bean id="tier2ContentStore" class="org.alfresco.repo.content.filestore.FileContentStore">
      <constructor-arg>
         <value>${dir.contentstore2}</value>
      </constructor-arg>
      
      <!-- Uncomment the property below to add content filesize limit.
      <property name="contentLimitProvider" ref="defaultContentLimitProvider"/>
      -->
  </bean>

  <bean id="tier3ContentStore" class="org.alfresco.repo.content.filestore.FileContentStore">
      <constructor-arg>
         <value>${dir.contentstore3}</value>
      </constructor-arg>
      
      <!-- Uncomment the property below to add content filesize limit.
      <property name="contentLimitProvider" ref="defaultContentLimitProvider"/>
      -->
  </bean>


  <!-- this is the aggregating content store - the name fileContentStore overrides the SkyVault default store -->
  <bean id="fileContentStore"
       class="org.alfresco.repo.content.replication.AggregatingContentStore" >

      <property name="primaryStore" ref="defaultContentStore" />
      
      <property name="secondaryStores">
          <list>
              <ref bean="tier1ContentStore" />
              <ref bean="tier2ContentStore" />
              <ref bean="tier3ContentStore" />
          </list>
      </property>
      
  </bean>
</beans>