Thomas Mueller created OAK-2761:
-----------------------------------
Summary: Persistent cache: add data in a different thread
Key: OAK-2761
URL: https://issues.apache.org/jira/browse/OAK-2761
Project: Jackrabbit Oak
Issue Type: Bug
Reporter: Thomas Mueller
Assignee: Thomas Mueller
The persistent cache usually stores data in a background thread, but sometimes
(if a lot of data is added quickly) the foreground thread is blocked.
Even worse, switching the cache file can happen in a foreground thread, with
the following stack trace.
{noformat}
"127.0.0.1 [1428931262206] POST /bin/replicate.json HTTP/1.1" prio=5
tid=0x00007fe5df819800 nid=0x9907 runnable [0x0000000113fc4000]
java.lang.Thread.State: RUNNABLE
...
at org.h2.mvstore.MVStoreTool.compact(MVStoreTool.java:404)
at
org.apache.jackrabbit.oak.plugins.document.persistentCache.PersistentCache$1.closeStore(PersistentCache.java:213)
- locked <0x0000000782483050> (a
org.apache.jackrabbit.oak.plugins.document.persistentCache.PersistentCache$1)
at
org.apache.jackrabbit.oak.plugins.document.persistentCache.PersistentCache.switchGenerationIfNeeded(PersistentCache.java:350)
- locked <0x0000000782455710> (a
org.apache.jackrabbit.oak.plugins.document.persistentCache.PersistentCache)
at
org.apache.jackrabbit.oak.plugins.document.persistentCache.NodeCache.write(NodeCache.java:85)
at
org.apache.jackrabbit.oak.plugins.document.persistentCache.NodeCache.put(NodeCache.java:130)
at
org.apache.jackrabbit.oak.plugins.document.DocumentNodeStore.applyChanges(DocumentNodeStore.java:1060)
at
org.apache.jackrabbit.oak.plugins.document.Commit.applyToCache(Commit.java:599)
at
org.apache.jackrabbit.oak.plugins.document.CommitQueue.afterTrunkCommit(CommitQueue.java:127)
- locked <0x0000000781890788> (a
org.apache.jackrabbit.oak.plugins.document.CommitQueue)
at
org.apache.jackrabbit.oak.plugins.document.CommitQueue.done(CommitQueue.java:83)
at
org.apache.jackrabbit.oak.plugins.document.DocumentNodeStore.done(DocumentNodeStore.java:637)
{noformat}
To avoid blocking the foreground thread, one solution is to store all data in a
separate thread. If there is too much data added, then some of the data is not
stored. If possible, the data that was not referenced a lot, and / or old
revisions of documents (if new revisions are available).
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
