How to modify the Ehcache settings?

Question

I want to increase the property timeToIdleSeconds for the caches using Ehcache in Jahia, how can I do that?

Answer

For reminder, the property timeToIdleSeconds has the following definition:

    Sets the time to idle for an element before it expires.
    i.e. The maximum amount of time between accesses before an element expires
    Is only used if the element is not eternal.
    Optional attribute. A value of 0 means that an Element can idle for infinity.
    The default value is 0.

Jahia has 4 files to configure the settings of the different default caches using Ehcache:

• JAHIA_HOME/tomcat/webapps/ROOT/WEB-INF/classes/ehcache-jahia.xml
• JAHIA_HOME/tomcat/webapps/ROOT/WEB-INF/classes/ehcache-jahia-html-cluster.xml
• JAHIA_HOME/tomcat/webapps/ROOT/WEB-INF/classes/ehcache-jahia-cluster.xml
• JAHIA_HOME/tomcat/webapps/ROOT/WEB-INF/classes/ehcache-jahia-html.xml

To do any change, it's advised to copy these files in the folder JAHIA_HOME/digital-factory-config then to modify the property timeToIdleSeconds accordingly. For example, for the file ehcache-jahia-html.xml:

<?xml version="1.0" encoding="UTF-8"?>
<ehcache xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:noNamespaceSchemaLocation="ehcache.xsd"
         updateCheck="false" monitoring="autodetect"
         name="org.jahia.ehcachemanager.big"
         dynamicConfig="true"
         maxBytesLocalHeap="${org.jahia.ehcachemanager.big.maxBytesLocalHeap:20%}">
    <transactionManagerLookup class="net.sf.ehcache.transaction.manager.DefaultTransactionManagerLookup"

    <cacheManagerEventListenerFactory class="" properties=""/>

    <sizeOfPolicy maxDepth="15000" maxDepthExceededBehavior="abort"/>

    <defaultCache timeToIdleSeconds="86400">
    </defaultCache>

    <cache name="HTMLCache"
           timeToIdleSeconds="86400">
    </cache>

    <cache name="HTMLDependenciesCache" timeToIdleSeconds="86400">
        <cacheEventListenerFactory class="org.jahia.services.cache.ehcache.DependenciesCacheEventListenerFactory" listenFor="local"/>
    </cache>

    <cache name="HTMLREGEXPDependenciesCache" timeToIdleSeconds="86400">
        <cacheEventListenerFactory class="org.jahia.services.cache.ehcache.DependenciesCacheEventListenerFactory" listenFor="local"/>
    </cache>

    <cache name="FileContentCache">
    </cache>

</ehcache>

Once it's done, you need to restart each node of the Jahia cluster so it's taken into account.

You might also encounter the situation where the cache is not configured thanks to an XML file but programmatically in Java. This is for example the case for the module Jahia LDAP connector:

    private Ehcache createLDAPCache(CacheManager cacheManager, String cacheName) {
        CacheConfiguration cacheConfiguration = cacheManager.getConfiguration().getDefaultCacheConfiguration() != null ?
                cacheManager.getConfiguration().getDefaultCacheConfiguration().clone() :
                new CacheConfiguration();
        cacheConfiguration.setName(cacheName);
        cacheConfiguration.setEternal(false);
        cacheConfiguration.setTimeToIdleSeconds(3600);
        // Create a new cache with the configuration
        Ehcache cache = new Cache(cacheConfiguration);
        cache.setName(cacheName);
        // Cache name has been set now we can initialize it by putting it in the manager.
        // Only Cache manager is initializing caches.
        return cacheManager.addCacheIfAbsent(cache);
    }

In that case, of course, you just have to modify the code accordingly, compile and deploy the module.