Develop Reference

Ehcache being emptied

I'm using Hibernate 4.2 and Ehcache 2.4.3 in my webapp and I've found out that my caches are constantly being cleared every few seconds (even the ones marked as eternal). There is no place in my code where I clear all the caches. Why is this happening?
Here is my ehcache.xml:
<?xml version="1.0" encoding="UTF-8"?>
<ehcache>
<diskStore path="java.io.tmp"/>
<defaultCache
maxElementsInMemory="1000000"
eternal="false"
overflowToDisk="false"
memoryStoreEvictionPolicy="LRU"/>
<cache name="[class A]"
maxElementsInMemory="250000"
eternal="false"
overflowToDisk="false"
memoryStoreEvictionPolicy="LRU"/>
<cache name="[class B]"
maxElementsInMemory="10"
eternal="true"
overflowToDisk="false"/>
</ehcache>
Here are my Tomcat's JAVA_OPTS:
-server -Xms32G -Xmx32G -XX:PermSize=512m -XX:+UseG1GC -XX:MaxGCPauseMillis=200 -XX:ParallelGCThreads=20 -XX:ConcGCThreads=5 -XX:InitiatingHeapOccupancyPercent=70 -XX:+DisableExplicitGC

Copy ehcache from one server to another

I have a tomcat server with ehcache. And I have a second tomcat with servlet. When second servlet is inited it should take ehcache from #1 and put all data to its cache.
Is there built-in mechanism such "on start replication" in ehcache? Or how can I get serialized ehcache data and then de-serialize them to ehcache. I understand that I can read all keys one by one and then all their values then serialize but maybe there's a better way?
Thanks

There is no out of the box support for what you are asking.
Alternatives are:
Ehcache clustering with Terracotta
Ehcache replication
Note that a major difference between the two is that the second option offers NO guarantees with regards to data consistency between the two Ehcache instances.
Disclaimer: I work for Terracotta on Ehcache

Here's my solution using built-in rmi replication solution:
Master config:
<ehcache xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:noNamespaceSchemaLocation="ehcache.xsd"
updateCheck="true"
monitoring="autodetect"
dynamicConfig="true">
<cacheManagerPeerListenerFactory
class="net.sf.ehcache.distribution.RMICacheManagerPeerListenerFactory"
properties="hostName=localhost, port=40001,
socketTimeoutMillis=2000"/>
<cache name="masterCache"
maxEntriesLocalHeap="10000"
eternal="false"
timeToIdleSeconds="300"
timeToLiveSeconds="600"
memoryStoreEvictionPolicy="LFU"
transactionalMode="off">
<cacheEventListenerFactory
class="net.sf.ehcache.distribution.RMICacheReplicatorFactory"
properties="replicateAsynchronously=true, replicatePuts=false, replicateUpdates=false,
replicateUpdatesViaCopy=false, replicateRemovals=false "/>
<persistence strategy="none"/>
</cache>
Here I turn on RMI listener for slaves and enable RMI for cache but without any replication because I just need data on slave when it starts and that's all
Slave config:
<ehcache xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:noNamespaceSchemaLocation="ehcache.xsd"
updateCheck="true"
monitoring="autodetect"
dynamicConfig="true">
<cacheManagerPeerProviderFactory
class="net.sf.ehcache.distribution.RMICacheManagerPeerProviderFactory"
properties="peerDiscovery=manual,
rmiUrls=//localhost:40001/masterCache"/>
<cache name="masterCache"
maxEntriesLocalHeap="10000"
eternal="false"
timeToIdleSeconds="300"
timeToLiveSeconds="600"
memoryStoreEvictionPolicy="LFU"
transactionalMode="off">
<bootstrapCacheLoaderFactory class="net.sf.ehcache.distribution.RMIBootstrapCacheLoaderFactory"
properties="bootstrapAsynchronously=false"/>
<persistence strategy="none"/>
</cache>
I made RMI connection to master node and turn on cache's bootstrap.

Error in JGROUPs for EhCache, drop message sender not in table

I have four nodes in a cluster, and I need synchronize them. When node BRJGSD309173 tried send a messages through JGROUPs to BRJGSD333007, the server BRJGSD333007 informed the message below:
11:34:07,759 WARN [org.jgroups.protocols.pbcast.NAKACK] (Incoming-2,maestroCacheManager,BRJGSD333007-24075) BRJGSD333007-24075: dropped message 4787 from BRJGSD309173-7667 (sender not in table [BRJGSD333007-24075]), view=[BRJGSD333007-24075|0] [BRJGSD333007-24075]
The follow configuration of eh jgroups_tcp.xml
<?xml version='1.0'?>
<config>
<TCP bind_port="7800"
max_bundle_size="5M" />
<TCPPING timeout="3000"
initial_hosts="brjgsm10.weg.net[7800],brjgsm11.weg.net[7800],brjgsd309173.weg.net[7800],brjgsd333007.weg.net[7800]"
port_range="10"
num_initial_members="5"/>
<VERIFY_SUSPECT timeout="1500" />
<pbcast.NAKACK use_mcast_xmit="false"
retransmit_timeout="300,600,1200,2400,4800"
discard_delivered_msgs="true"/>
<pbcast.STABLE stability_delay="1000" desired_avg_gossip="50000" max_bytes="400000"/>
<pbcast.GMS print_local_addr="true" join_timeout="5000" view_bundling="true"/>
</config>
And a fragment of ehcache.xml
<ehcache xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
updateCheck="false" xsi:noNamespaceSchemaLocation="ehcache.xsd" name="maestroCacheManager">
...
<cache
name="objectServiceExecute"
maxEntriesLocalHeap="100000"
eternal="false" >
<cacheEventListenerFactory
class="net.sf.ehcache.distribution.jgroups.JGroupsCacheReplicatorFactory"
properties="replicateAsynchronously=true, replicatePuts=true,
replicateUpdates=true, replicateUpdatesViaCopy=true, replicateRemovals=true" />
</cache>
<diskStore
path="java.io.tmpdir/ehcache" />
<cacheManagerPeerProviderFactory
class="net.sf.ehcache.distribution.jgroups.JGroupsCacheManagerPeerProviderFactory"
properties="file=jgroups_tcp.xml"
propertySeparator=";"
/>
<cache
name="org.hibernate.cache.internal.StandardQueryCache"
maxElementsInMemory="10000000"
eternal="true"
memoryStoreEvictionPolicy="LRU" />
<defaultCache
maxElementsInMemory="10000000"
eternal="true"
memoryStoreEvictionPolicy="LRU" >
<cacheEventListenerFactory
class="net.sf.ehcache.distribution.jgroups.JGroupsCacheReplicatorFactory"
properties="replicateAsynchronously=true, replicatePuts=true,
replicateUpdates=true, replicateUpdatesViaCopy=true, replicateRemovals=true" />
</defaultCache>
</ehcache>

This is a very stange JGroups configuration! You're missing failure detection protocols, UNICAST3 and MERFGE3 etc!
The error above means that you received a message from a member not in the cluster, so it was consequently dropped. Why the member was not in the cluster is unclear, perhaps it didn't join correctly. Since you don't have any failure detection protocols, it can't have been suspected and expelled.
I suggest copy tcp.xml shipped with JGroups and replace TCPPING with your TCPPING config. Also make sure you set bind_addr in TCP, to make sure JGroups binds to the correct interface.
Hope this helps,
Cheers

UpdateTimestampsCache not appearing in Terracotta Dev Console

I have configured ehcache for hibernate 2nd level cache to use a Terracotta server. Everything is working fine, except the UpdateTimestampsCache for the query cache is just not showing up in the Dev Console. We are using Hibernate 3.6.10 and ehcache 2.6.0.
I am seeing all entity, collection, query and the StandardQueryCache, but not org.hibernate.cache.UpdateTimestampsCache. I know the timestamp cache exists and is being used because I can see the stats on it using the the metrics lib instrumented in.
Any ideas?
Thanks!
Here's my ehcache.xml config
<ehcache xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:noNamespaceSchemaLocation="http://ehcache.org/ehcache.xsd"
updateCheck="false"
name="Hibernate-CacheManager"
monitoring="autodetect"
dynamicConfig="true">
<terracottaConfig url="localhost:9510" />
<defaultCache
eternal="false"
overflowToDisk="false"
maxElementsInMemory="50000"
timeToIdleSeconds="7200"
timeToLiveSeconds="0">
<cacheDecoratorFactory
class="com.yammer.metrics.ehcache.InstrumentedEhcacheFactory" />
<terracotta/>
</defaultCache>
<cache
name="org.hibernate.cache.UpdateTimestampsCache"
eternal="false"
overflowToDisk="false"
maxElementsInMemory="500"
timeToIdleSeconds="7200"
timeToLiveSeconds="0">
<cacheDecoratorFactory
class="com.yammer.metrics.ehcache.InstrumentedEhcacheFactory" />
<terracotta/>
</cache>
<cache
name="org.hibernate.cache.StandardQueryCache"
eternal="false"
overflowToDisk="false"
maxElementsInMemory="50000"
timeToIdleSeconds="7200"
timeToLiveSeconds="0">
<cacheDecoratorFactory
class="com.yammer.metrics.ehcache.InstrumentedEhcacheFactory" />
<terracotta/>
</cache>
</ehcache>

Recopying answer from: http://forums.terracotta.org/forums/posts/list/0/7554.page#36815
Hibernate does not maintain statistics for the UpdateTimestampsCache cache up to Hibernate 4.0.0. This explains why the cache does not show up in the terracotta dev console.
This is filed as bug https://hibernate.onjira.com/browse/HHH-5326

Not able to configure JPA with ehcache

I have been trying to configure JPA with ehcache but no success till now. The configurations which i am doing are :
persistence.xml
<persistence-unit name="customDatabase">
<jta-data-source>jdbc/oracleXE_DS</jta-data-source>
<class>com.td.waw.cse.entities.Product</class>
<properties>
<property name="openjpa.Log" value="DefaultLevel=TRACE, Runtime=INFO, Tool=INFO, SQL=TRACE"/>
<property name="openjpa.QueryCache" value="net.sf.ehcache.openjpa.datacache.EhCacheQueryCache"/>
<property name="openjpa.DataCacheManager" value="net.sf.ehcache.openjpa.datacache.EhCacheDataCacheManager"/>
<property name="openjpa.DataCache" value="net.sf.ehcache.openjpa.datacache.EhCacheDataCache"/>
<property name="openjpa.RemoteCommitProvider" value="net.sf.ehcache.openjpa.datacache.NoOpRemoteCommitProvider"/>
</properties>
ehcache.xml
<ehcache xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:noNamespaceSchemaLocation="ehcache.xsd"
updateCheck="true" monitoring="autodetect"
dynamicConfig="true" >
<defaultCache
maxElementsInMemory="1000"
eternal="false"
timeToIdleSeconds="300"
timeToLiveSeconds="600"
overflowToDisk="false"
memoryStoreEvictionPolicy="LRU"
/>
<!-- OpenJPA data cache -->
<cache name="openjpa"
maxElementsInMemory="5000"
eternal="false"
timeToIdleSeconds="300"
timeToLiveSeconds="600"
overflowToDisk="false"
memoryStoreEvictionPolicy="LRU"
/>
<!-- OpenJPA query cache -->
<cache name="openjpa-querycache"
maxElementsInMemory="1000"
eternal="false"
timeToIdleSeconds="300"
timeToLiveSeconds="600"
overflowToDisk="false"
memoryStoreEvictionPolicy="LRU"
/>
</ehcache>
Product.java
#Entity
#Table(name="PRODUCT")
#NamedQueries({#NamedQuery(name="getAllProducts", query = "select products from Product products")})
public class Product implements Serializable {}
I am not getting any exception but i could not see the ehcache working as nothing specific to ehcache printed in the logs.
I would really appreciate if someone can help in this.

Add the following properties in persistence.xml:
<property name="openjpa.QueryCache" value="ehcache"/>
<property name="openjpa.DataCacheManager" value="ehcache"/>
Add the following jars in classpath:ehcache-core-2.4.4.jar, ehcache-openjpa-0.2.0.jar and slf4j-api-1.6.1.jar.
That's all.
Jar Downloads:
link - http://ehcache.org/downloads/catalog?activated=true
ehcache-core-2.4.4.jar and slf4j-api-1.6.1.jar - ehcache-core-2.4.4-distribution.tar.gz module
ehcache-openjpa-0.2.0.jar - ehcache-openjpa-0.2.0-distribution.tar.gz
References
L2 caching explained - http://blogs.oracle.com/carolmcdonald/entry/jpa_caching
OpenJPA L2 caching implementation - http://openjpa.apache.org/builds/1.0.2/apache-openjpa-1.0.2/docs/manual/ref_guide_caching.html
Ehcache OpenJPA implementation - http://www.ehcache.org/documentation/user-guide/openjpa-provider

DataNucleus works perfectly fine with EHCache, with the config specified here
http://www.datanucleus.org/products/accessplatform_2_2/jpa/cache.html#ehcache
It will print log messages about the L2 cache whenever it is accessed. You don't mention your JPA provider.