Mailing-List: contact dev-help@lucene.apache.org; run by ezmlm
Precedence: bulk
Reply-To: dev@lucene.apache.org
Message-ID: <22085472.131891280803696308.JavaMail.jira@thor>
Date: Mon, 2 Aug 2010 22:48:16 -0400 (EDT)
From: "Alexander Kanarsky (JIRA)" <jira@apache.org>
To: dev@lucene.apache.org
Subject: [jira] Created: (LUCENE-2584) Concurrency issues in
 SegmentInfo.files() could lead to ConcurrentModificationException
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit

Concurrency issues in SegmentInfo.files() could lead to ConcurrentModificationException
---------------------------------------------------------------------------------------

                 Key: LUCENE-2584
                 URL: https://issues.apache.org/jira/browse/LUCENE-2584
             Project: Lucene - Java
          Issue Type: Bug
    Affects Versions: 3.0.2, 3.0.1, 3.0, 2.9.3, 2.9.2, 2.9.1, 2.9
            Reporter: Alexander Kanarsky
            Priority: Minor


The multi-threaded call of the files() in SegmentInfo could lead to the ConcurrentModificationException if one thread is not finished additions to the ArrayList (files) yet while the other thread already obtained it as cached (see below). This is a rare exception, but it would be nice to fix. I see the code is no longer problematic in the trunk (and others ported from flex_1458), looks it was fixed while implementing post 3.x features. The fix to 3.x and 2.9.x branches could be the same - create the files set first and populate it, and then assign to the member variable at the end of the method. This will resolve the issue. I could prepare the patch for 2.9.4 and 3.x, if needed.

--

INFO: [19] webapp= path=/replication params={command=fetchindex&wt=javabin} status=0 QTime=1
Jul 30, 2010 9:13:05 AM org.apache.solr.core.SolrCore execute
INFO: [19] webapp= path=/replication params={command=details&wt=javabin} status=0 QTime=24
Jul 30, 2010 9:13:05 AM org.apache.solr.handler.ReplicationHandler doFetch
SEVERE: SnapPull failed
java.util.ConcurrentModificationException
        at java.util.AbstractList$Itr.checkForComodification(AbstractList.java:372)
        at java.util.AbstractList$Itr.next(AbstractList.java:343)
        at java.util.AbstractCollection.addAll(AbstractCollection.java:305)
        at org.apache.lucene.index.SegmentInfos.files(SegmentInfos.java:826)
        at org.apache.lucene.index.DirectoryReader$ReaderCommit.<init>(DirectoryReader.java:916)
        at org.apache.lucene.index.DirectoryReader.getIndexCommit(DirectoryReader.java:856)
        at org.apache.solr.search.SolrIndexReader.getIndexCommit(SolrIndexReader.java:454)
        at org.apache.solr.handler.SnapPuller.fetchLatestIndex(SnapPuller.java:261)
        at org.apache.solr.handler.ReplicationHandler.doFetch(ReplicationHandler.java:264)
        at org.apache.solr.handler.ReplicationHandler$1.run(ReplicationHandler.java:146)


-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.


---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe@lucene.apache.org
For additional commands, e-mail: dev-help@lucene.apache.org