You are viewing a plain text version of this content. The canonical link for it is here.
Posted to oak-issues@jackrabbit.apache.org by "Chetan Mehrotra (JIRA)" <ji...@apache.org> on 2015/03/04 05:24:04 UTC

[jira] [Created] (OAK-2570) Open indexes in IndexTracker non blocking way

Chetan Mehrotra created OAK-2570:
------------------------------------

             Summary: Open indexes in IndexTracker non blocking way
                 Key: OAK-2570
                 URL: https://issues.apache.org/jira/browse/OAK-2570
             Project: Jackrabbit Oak
          Issue Type: Improvement
          Components: oak-lucene
            Reporter: Chetan Mehrotra
            Assignee: Chetan Mehrotra
             Fix For: 1.2, 1.0.12


Currently {{IndexTracker}} opens the indexes in same thread where the commit happens as it acts as an {{Observer}}. If opening the index takes long time it would block the commit thread and might introduce delay in other operation on same thread. 

For example {{DocumentNodeStore}} invokes the {{Observer}} in {{backgroundRead}} and that call would not complete unless the {{Observer}} returns back. For a system to be responsive the {{backgroundRead}} has to be quick as it holds the write lock. Due to current implementation at time system turn unresponsive. 

Looking at the threaddump from one such unresponsive system it appears that slowness is due to Lucene index taking time to reopen. 

Thread which hold the {{backgroundOperationLock}} for {{read}} is 
{noformat}
"pool-9-thread-1" Id=101 in RUNNABLE
    at java.io.FileInputStream.open(Native Method)
    at java.io.FileInputStream.<init>(FileInputStream.java:146)
    at org.apache.jackrabbit.core.data.LazyFileInputStream.open(LazyFileInputStream.java:104)
    at org.apache.jackrabbit.core.data.LazyFileInputStream.read(LazyFileInputStream.java:163)
    at com.google.common.io.ByteStreams.read(ByteStreams.java:828)
    at com.google.common.io.ByteStreams.readFully(ByteStreams.java:695)
    at org.apache.jackrabbit.oak.plugins.index.lucene.OakDirectory$OakIndexFile.loadBlob(OakDirectory.java:218)
    at org.apache.jackrabbit.oak.plugins.index.lucene.OakDirectory$OakIndexFile.readBytes(OakDirectory.java:264)
    at org.apache.jackrabbit.oak.plugins.index.lucene.OakDirectory$OakIndexInput.readBytes(OakDirectory.java:350)
    at org.apache.jackrabbit.oak.plugins.index.lucene.OakDirectory$OakIndexInput.readByte(OakDirectory.java:356)
    at org.apache.lucene.store.DataInput.readInt(DataInput.java:84)
    at org.apache.lucene.codecs.CodecUtil.checkHeader(CodecUtil.java:126)
    at org.apache.lucene.util.fst.FST.<init>(FST.java:318)
    at org.apache.lucene.util.fst.FST.<init>(FST.java:304)
    at org.apache.lucene.codecs.BlockTreeTermsReader$FieldReader.<init>(BlockTreeTermsReader.java:484)
    at org.apache.lucene.codecs.BlockTreeTermsReader.<init>(BlockTreeTermsReader.java:176)
    at org.apache.lucene.codecs.lucene41.Lucene41PostingsFormat.fieldsProducer(Lucene41PostingsFormat.java:437)
    at org.apache.lucene.index.SegmentCoreReaders.<init>(SegmentCoreReaders.java:116)
    at org.apache.lucene.index.SegmentReader.<init>(SegmentReader.java:96)
    at org.apache.lucene.index.StandardDirectoryReader$1.doBody(StandardDirectoryReader.java:62)
    at org.apache.lucene.index.SegmentInfos$FindSegmentsFile.run(SegmentInfos.java:843)
    at org.apache.lucene.index.StandardDirectoryReader.open(StandardDirectoryReader.java:52)
    at org.apache.lucene.index.DirectoryReader.open(DirectoryReader.java:66)
    at org.apache.jackrabbit.oak.plugins.index.lucene.IndexNode.<init>(IndexNode.java:94)
    at org.apache.jackrabbit.oak.plugins.index.lucene.IndexNode.open(IndexNode.java:62)
    at org.apache.jackrabbit.oak.plugins.index.lucene.IndexTracker$1.leave(IndexTracker.java:96)
    at org.apache.jackrabbit.oak.spi.commit.EditorDiff.childNodeChanged(EditorDiff.java:153)
    at org.apache.jackrabbit.oak.plugins.document.DocumentNodeState.dispatch(DocumentNodeState.java:433)
    at org.apache.jackrabbit.oak.plugins.document.DocumentNodeState.compareAgainstBaseState(DocumentNodeState.java:260)
    at org.apache.jackrabbit.oak.spi.commit.EditorDiff.childNodeChanged(EditorDiff.java:148)
    at org.apache.jackrabbit.oak.plugins.document.DocumentNodeState.dispatch(DocumentNodeState.java:433)
    at org.apache.jackrabbit.oak.plugins.document.DocumentNodeState.compareAgainstBaseState(DocumentNodeState.java:260)
    at org.apache.jackrabbit.oak.spi.commit.EditorDiff.process(EditorDiff.java:52)
    at org.apache.jackrabbit.oak.plugins.index.lucene.IndexTracker.update(IndexTracker.java:105)
      - locked org.apache.jackrabbit.oak.plugins.index.lucene.IndexTracker@6243264e
    at org.apache.jackrabbit.oak.plugins.index.lucene.LuceneIndexProvider.contentChanged(LuceneIndexProvider.java:61)
    at org.apache.jackrabbit.oak.spi.commit.CompositeObserver.contentChanged(CompositeObserver.java:53)
      - locked org.apache.jackrabbit.oak.spi.commit.CompositeObserver@2687fd48
    at org.apache.jackrabbit.oak.spi.commit.ChangeDispatcher.contentChanged(ChangeDispatcher.java:79)
      - locked org.apache.jackrabbit.oak.spi.commit.ChangeDispatcher@2a0595bb
    at org.apache.jackrabbit.oak.plugins.document.CommitQueue.afterTrunkCommit(CommitQueue.java:131)
      - locked org.apache.jackrabbit.oak.plugins.document.CommitQueue@54a93d8a
    at org.apache.jackrabbit.oak.plugins.document.CommitQueue.done(CommitQueue.java:83)
    at org.apache.jackrabbit.oak.plugins.document.DocumentNodeStore.done(DocumentNodeStore.java:586)
    at org.apache.jackrabbit.oak.plugins.document.DocumentNodeStoreBranch.persist(DocumentNodeStoreBranch.java:187)
    at org.apache.jackrabbit.oak.plugins.document.DocumentNodeStoreBranch.persist(DocumentNodeStoreBranch.java:91)
    at org.apache.jackrabbit.oak.plugins.document.DocumentNodeStoreBranch.persist(DocumentNodeStoreBranch.java:39)
    at org.apache.jackrabbit.oak.spi.state.AbstractNodeStoreBranch$InMemory.merge(AbstractNodeStoreBranch.java:525)
    at org.apache.jackrabbit.oak.spi.state.AbstractNodeStoreBranch.merge(AbstractNodeStoreBranch.java:318)
    at org.apache.jackrabbit.oak.plugins.document.DocumentNodeStoreBranch.merge(DocumentNodeStoreBranch.java:135)
    at org.apache.jackrabbit.oak.plugins.document.DocumentRootBuilder.merge(DocumentRootBuilder.java:159)
    at org.apache.jackrabbit.oak.plugins.document.DocumentNodeStore.merge(DocumentNodeStore.java:1339)
    at org.apache.jackrabbit.oak.plugins.index.AsyncIndexUpdate.mergeWithConcurrencyCheck(AsyncIndexUpdate.java:420)
    at org.apache.jackrabbit.oak.plugins.index.AsyncIndexUpdate.updateIndex(AsyncIndexUpdate.java:389)
    at org.apache.jackrabbit.oak.plugins.index.AsyncIndexUpdate.run(AsyncIndexUpdate.java:300)
      - locked org.apache.jackrabbit.oak.plugins.index.AsyncIndexUpdate@401daa3f
    at org.apache.sling.commons.scheduler.impl.QuartzJobExecutor.execute(QuartzJobExecutor.java:105)
    at org.quartz.core.JobRunShell.run(JobRunShell.java:207)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:745)
{noformat}

Further {{DocumentNodeStore background thread}} is also waiting to acquire the write lock

{noformat}
"DocumentNodeStore background thread" Id=82 in WAITING on lock=java.util.concurrent.locks.ReentrantReadWriteLock$NonfairSync@6990d994
    at sun.misc.Unsafe.park(Native Method)
    at java.util.concurrent.locks.LockSupport.park(LockSupport.java:186)
    at java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:834)
    at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireQueued(AbstractQueuedSynchronizer.java:867)
    at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(AbstractQueuedSynchronizer.java:1197)
    at java.util.concurrent.locks.ReentrantReadWriteLock$WriteLock.lock(ReentrantReadWriteLock.java:945)
    at org.apache.jackrabbit.oak.plugins.document.UnsavedModifications.persist(UnsavedModifications.java:156)
    at org.apache.jackrabbit.oak.plugins.document.DocumentNodeStore.backgroundWrite(DocumentNodeStore.java:1662)
    at org.apache.jackrabbit.oak.plugins.document.DocumentNodeStore.runBackgroundOperations(DocumentNodeStore.java:1456)
      - locked org.apache.jackrabbit.oak.plugins.document.DocumentNodeStore@350b4c49
    at org.apache.jackrabbit.oak.plugins.document.DocumentNodeStore$BackgroundOperation.execute(DocumentNodeStore.java:2064)
    at org.apache.jackrabbit.oak.plugins.document.DocumentNodeStore$NodeStoreTask.run(DocumentNodeStore.java:2039)
    at java.lang.Thread.run(Thread.java:745)
{noformat}

Now as javadoc of {{ReentrantReadWriteLock}} the readLock would not be granted if there is a waiter for write lock. Hence in such a case no further reads would be possible and system would not respond well



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)