lucene-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Michael McCandless (JIRA)" <j...@apache.org>
Subject [jira] Commented: (LUCENE-1453) When reopen returns a new IndexReader, both IndexReaders may now control the lifecycle of the underlying Directory which is managed by reference counting
Date Tue, 09 Jun 2009 18:42:07 GMT

    [ https://issues.apache.org/jira/browse/LUCENE-1453?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12717781#action_12717781
] 

Michael McCandless commented on LUCENE-1453:
--------------------------------------------

Good question :)  Exceptions in close are tricky...

In some places we try hard to keep closing stuff, and then throw the
first exception we hit.  Probably that should be our preferred
approach, in general, for readers?  (My guess is most apps simply
catch & log the IOException, so, we should try hard to close all that
we can on the first go.)

In other places (SR, DR) we don't.

In general you can retry a close -- calling close more than once on
Lucene classes is allowed (or, we aim for that, but likely not all
classes achieve it).

For writers (IndexWriter, and DR with pending changes) we try hard not
to lose state on hitting an exception during close.  Meaning, on
hitting an exception in close, either 1) your state already made it
into the index, or 2) if you fix the root cause (free up disk space,
fix permisisions, whatever, which of course hardly any app is going to
be doing) and retry the close, it would succeed, and your index would
be fine and your changes are committed.


> When reopen returns a new IndexReader, both IndexReaders may now control the lifecycle
of the underlying Directory which is managed by reference counting
> ---------------------------------------------------------------------------------------------------------------------------------------------------------
>
>                 Key: LUCENE-1453
>                 URL: https://issues.apache.org/jira/browse/LUCENE-1453
>             Project: Lucene - Java
>          Issue Type: Bug
>    Affects Versions: 2.4
>            Reporter: Mark Miller
>            Assignee: Michael McCandless
>            Priority: Minor
>             Fix For: 2.4.1, 2.9
>
>         Attachments: Failing-testcase-LUCENE-1453.patch, LUCENE-1453-with-FSDir-open.patch,
LUCENE-1453.patch, LUCENE-1453.patch, LUCENE-1453.patch, LUCENE-1453.patch
>
>
> Rough summary. Basically, FSDirectory tracks references to FSDirectory and when IndexReader.reopen
shares a Directory with a created IndexReader and closeDirectory is true, FSDirectory's ref
management will see two decrements for one increment. You can end up getting an AlreadyClosed
exception on the Directory when the IndexReader is open.
> I have a test I'll put up. A solution seems fairly straightforward (at least in what
needs to be accomplished).

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


Mime
View raw message