Weird TreeCache.printDetails()

[ottuzzi]

Hi there,

I'm getting strange results from the method TreeCache.printDetails().
I'm constructing a tree like:

/USER
 /USER_ID_1
 /INFO
 ...
 ...
 /USER_ID_2
 ...
 ...
 /USER_ID_N

When the cache is initialized everything is OK but after some time (say 1 hour) the printDetails() method show something like this:

/USER
jboss:internal:uninitialized: null

 /30815

 /31135
jboss:internal:uninitialized: null

 /31137

 /29970
jboss:internal:uninitialized: null

 /29544

Should I get worried?
Am I doing something wrong?
The log says:

2007-02-15 10:42:33,190 DEBUG - process(): region: /USER/
2007-02-15 10:42:33,190 DEBUG - processed 0 node events in region: /USER/
2007-02-15 10:42:33,190 DEBUG - Recycle queue is empty

Many thanks
Bye
Piero

[genman]

The "jboss:internal:..." data key indicates that the node was evicted to disk and thus if accessed again should be loaded from disk.

[ottuzzi]

Hi Genman,all,

thank you for your reply.
I'm a little bit surprised by your response because I do not use any cacheLoader... here is my configuration:

<?xml version="1.0" encoding="UTF-8"?>
<server>

 <classpath codebase="./lib" archives="jboss-cache.jar, jgroups.jar"/>

 <mbean code="org.jboss.cache.TreeCache"
 name="jboss.cache:service=TreeCache">

 <depends>jboss:service=Naming</depends>
 <depends>jboss:service=TransactionManager</depends>

 <attribute name="TransactionManagerLookupClass">org.jboss.cache.GenericTransactionManagerLookup</attribute>

 <attribute name="NodeLockingScheme">PESSIMISTIC</attribute>
 <attribute name="IsolationLevel">READ_COMMITTED</attribute>
 <attribute name="CacheMode">REPL_ASYNC</attribute>

 <attribute name="UseReplQueue">false</attribute>
 <attribute name="ReplQueueInterval">1000</attribute>
 <attribute name="ReplQueueMaxElements">5</attribute>

 <attribute name="ClusterName">TreeCache-RA-Cluster</attribute>
 <attribute name="ClusterConfig">
 <config>
 <UDP mcast_addr="228.1.2.3" mcast_port="48866"
 ip_ttl="64" ip_mcast="true"
 mcast_send_buf_size="150000" mcast_recv_buf_size="80000"
 ucast_send_buf_size="150000" ucast_recv_buf_size="80000"
 loopback="false"/>
 <PING timeout="2000" num_initial_members="3"
 up_thread="false" down_thread="false"/>
 <MERGE2 min_interval="10000" max_interval="20000"/>
 <FD_SOCK/>
 <VERIFY_SUSPECT timeout="1500"
 up_thread="false" down_thread="false"/>
 <pbcast.NAKACK gc_lag="50" retransmit_timeout="600,1200,2400,4800"
 max_xmit_size="8192" up_thread="false" down_thread="false"/>
 <UNICAST timeout="600,1200,2400" down_thread="false"/>
 <pbcast.STABLE desired_avg_gossip="20000"
 up_thread="false" down_thread="false"/>
 <pbcast.GMS join_timeout="5000" join_retry_timeout="2000"
 shun="true" print_local_addr="true"/>
 <FC max_credits="2000000" down_thread="false" up_thread="false"
 min_threshold="0.20"/>
 <FRAG frag_size="8192" down_thread="false" up_thread="true"/>
 <pbcast.STATE_TRANSFER up_thread="true" down_thread="true"/>
 </config>
 </attribute>

 <attribute name="FetchInMemoryState">true</attribute>

 <attribute name="InitialStateRetrievalTimeout">20000</attribute>

 <attribute name="SyncReplTimeout">20000</attribute>

 <attribute name="LockAcquisitionTimeout">15000</attribute>

 <attribute name="EvictionPolicyClass">org.jboss.cache.eviction.LRUPolicy</attribute>

 <attribute name="EvictionPolicyConfig">
 <config>
 <attribute name="wakeUpIntervalSeconds">30</attribute><!-- 30 SECONDS -->
 <!-- Cache wide default -->
 <region name="/_default_">
 <attribute name="maxNodes">10000</attribute>
 <attribute name="timeToLiveSeconds">1800</attribute><!-- 30 MINUTES -->
 <attribute name="maxAgeSeconds">1800</attribute><!-- 30 MINUTES -->
 </region>
 <region name="/USER/">
 <attribute name="maxNodes">1000</attribute>
 <attribute name="timeToLiveSeconds">900</attribute><!-- 15 MINUTES -->
 <attribute name="maxAgeSeconds">900</attribute><!-- 15 MINUTES -->
 </region>
 </config>
 </attribute>

 <attribute name="UseRegionBasedMarshalling">true</attribute>

 </mbean>

</server>

What you say can explain some behaviour I observed but it open many more questions:
1) is it a default that I can disable?
2) where is it saving cached objects on disk?

Many thanks for your patience... I really love to understand how things works.

Bye
Piero

[manik]

It doesn't matter if you use a cache loader or not. If you have an eviction policy set up, it will start to clear stuff from memory if it fills up.

Usually this involves removing a node, but if the node has children, then it will just remove the data in the node and mark the node as uninitialised.

HTH.