[ https://issues.apache.org/jira/browse/LUCENE-1383?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12630845#action_12630845 ]
chrislusf edited comment on LUCENE-1383 at 9/13/08 7:12 PM: ----------------------------------------------------------- On second thought, I think this is normal behavior. Like you said, the GC may take a while before really cleaning up stuff. So if I did not wait a while between the close and open, the little bump should be normal. So I would say this bug is fixed. Thanks! was (Author: chrislusf): On second thought, I think this is normal behavior. Like you said, the GC may take a while before really cleaning up stuff. So if I did not wait a while before the close and open, the little bump should be normal. So I would say this bug is fixed. Thanks! > Work around ThreadLocal's "leak" > -------------------------------- > > Key: LUCENE-1383 > URL: https://issues.apache.org/jira/browse/LUCENE-1383 > Project: Lucene - Java > Issue Type: Bug > Components: Index > Affects Versions: 1.9, 2.0.0, 2.1, 2.2, 2.3, 2.3.1, 2.3.2 > Reporter: Michael McCandless > Assignee: Michael McCandless > Fix For: 2.4 > > Attachments: LUCENE-1383.patch, ScreenHunter_01 Sep. 13 08.40.jpg, > ScreenHunter_02 Sep. 13 08.42.jpg, ScreenHunter_03 Sep. 13 08.43.jpg > > > Java's ThreadLocal is dangerous to use because it is able to take a > surprisingly very long time to release references to the values you > store in it. Even when a ThreadLocal instance itself is GC'd, hard > references to the values you had stored in it are easily kept for > quite some time later. > While this is not technically a "memory leak", because eventually > (when the underlying Map that stores the values cleans up its "stale" > references) the hard reference will be cleared, and GC can proceed, > its end behavior is not different from a memory leak in that under the > right situation you can easily tie up far more memory than you'd > expect, and then hit unexpected OOM error despite allocating an > extremely large heap to your JVM. > Lucene users have hit this many times. Here's the most recent thread: > > http://mail-archives.apache.org/mod_mbox/lucene-java-dev/200809.mbox/%3C6e3ae6310809091157j7a9fe46bxcc31f6e63305fcdc%40mail.gmail.com%3E > And here's another: > > http://mail-archives.apache.org/mod_mbox/lucene-java-dev/200807.mbox/%3CF5FC94B2-E5C7-40C0-8B73-E12245B91CEE%40mikemccandless.com%3E > And then there's LUCENE-436 and LUCENE-529 at least. > A google search for "ThreadLocal leak" yields many compelling hits. > Sun does this for performance reasons, but I think it's a terrible > trap and we should work around it with Lucene. -- 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: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]