[jbosscache-issues] [JBoss JIRA] Updated: (JBCACHE-1544) Optimistic locking and eviction

[Galder Zamarreno (JIRA)]

     [ https://jira.jboss.org/jira/browse/JBCACHE-1544?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Galder Zamarreno updated JBCACHE-1544:
--------------------------------------

    Attachment: patch-v1.txt
                jboss-cache-jdk50.jar


I've got a potential one liner fix for this:

Index: src/org/jboss/cache/TreeCache.java
===================================================================
--- src/org/jboss/cache/TreeCache.java	(revision 8231)
+++ src/org/jboss/cache/TreeCache.java	(working copy)
@@ -5105,7 +5105,7 @@
       boolean eviction = true;
       if (log.isTraceEnabled())
          log.trace("_evict(" + fqn + ")");
-      if (hasChild(fqn))
+      if (hasChild(fqn) || isNodeLockingOptimistic())
       {
          _removeData(null, fqn, create_undo_ops, sendNodeEvent, eviction);
          return false;

Basically, if optimistic, never evict the whole node, but just delete the data. This will leave the version hanging around which makes the test in the patch pass.

I'm uploading a jboss-cache-jdk50.jar containing this patch.

> Optimistic locking and eviction
> -------------------------------
>
>                 Key: JBCACHE-1544
>                 URL: https://jira.jboss.org/jira/browse/JBCACHE-1544
>             Project: JBoss Cache
>          Issue Type: Bug
>      Security Level: Public(Everyone can see) 
>    Affects Versions: 1.4.1.SP13
>            Reporter: Mircea Markus
>            Assignee: Galder Zamarreno
>         Attachments: cluster-evictor.tar.gz, jboss-cache-jdk50.jar, optimistic-replicated-eviction.xml, OptimisticReplicatedEvictionTest.java, patch-v1.txt
>
>
> Since eviction is done per node, it is easy to get the cache into a bad
> state. For example, a 2-node cluster, OPTIMISTIC, REPL_SYNC, 60 second
> eviction:
> On Node A:
> cache.put ( "/foo", 0, 0 ); // this could be from any node
> for ( ;; ) {
> Thread.sleep ( 30000 ); // wait 30 seconds
> cache.get ( "/foo", 0 ); // refresh the eviction timer so the node will
> never be evicted on A
> }
> ---------
> This is just using the default JBC versioning, and direct cache access.
>  No hibernate.
> There's no special configuration for the cache except what I listed
> (OPTIMISTIC, REPL_SYNC, 60 second
> eviction). No code hitting the cache except what I listed below.
> By the way, this is EAP 4.3 CP05 (JBC 1.4.1.SP13).
> On Node B:
> // wait at least 60 seconds after the original put for the node to be
> evicted on B
> cache.put ( "/foo", 0, 0 ); // will always fail during replication to A:
> org.jboss.cache.optimistic.DataVersioningException: DataNode [/foo]
> version Ver=2 is newer than workspace node Ver=1

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