lucene-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Earwin Burrfoot (JIRA)" <j...@apache.org>
Subject [jira] Issue Comment Edited: (LUCENE-1658) Absorb NIOFSDirectory into FSDirectory
Date Mon, 01 Jun 2009 11:16:07 GMT

    [ https://issues.apache.org/jira/browse/LUCENE-1658?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12715063#action_12715063
] 

Earwin Burrfoot edited comment on LUCENE-1658 at 6/1/09 4:16 AM:
-----------------------------------------------------------------

bq. On a couple of projects I've worked in, they were very reluctant to having packages allocate
memory outside the JVM, and that's my understanding of memory mapped buffers.
mmap does not allocate memory. It allocates address space, and uses the same disk cache system
already has.
For example, you can't cause OOM in your (or another co-existing) app with mmaps (except eating
up your own address space on 32bit systems).

bq. But if you decide to include MMapDir in that auto-create logic, I hope there will be a
way to instantiate a specific FSDir, in case we'll have problems with that logic.
Public constructors for all D variants are a must, and for me they are the best that this
patch has to offer :)

      was (Author: earwin):
    bq. On a couple of projects I've worked in, they were very reluctant to having packages
allocate memory outside the JVM, and that's my understanding of memory mapped buffers.
mmap does not allocate memory. It allocates address space, and uses the same disk cache system
already has.
For example, you can't cause OOM in your (or another co-existing) app with mmaps (except eating
up your own address space on 32bit systems).
  
> Absorb NIOFSDirectory into FSDirectory
> --------------------------------------
>
>                 Key: LUCENE-1658
>                 URL: https://issues.apache.org/jira/browse/LUCENE-1658
>             Project: Lucene - Java
>          Issue Type: Improvement
>          Components: Store
>            Reporter: Michael McCandless
>            Assignee: Uwe Schindler
>            Priority: Minor
>             Fix For: 2.9
>
>         Attachments: LUCENE-1658-take2.patch, LUCENE-1658-take2.patch, LUCENE-1658-take3.patch,
LUCENE-1658-take3.patch, LUCENE-1658-take3.patch, LUCENE-1658-take3.patch, LUCENE-1658-take3.patch,
LUCENE-1658.patch, LUCENE-1658.patch, LUCENE-1658.patch
>
>
> I think whether one uses java.io.* vs java.nio.* or eventually
> java.nio2.*, or some other means, is an under-the-hood implementation
> detail of FSDirectory and doesn't merit a whole separate class.
> I think FSDirectory should be the core class one uses when one's index
> is in the filesystem.
> So, I'd like to deprecate NIOFSDirectory, absorbing it into
> FSDirectory, and add a setting "useNIO" to FSDirectory.  It should
> default to "true" for non-Windows OSs, because it gives far better
> concurrent performance on all platforms but Windows (due to known Sun
> JRE issue http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6265734).

-- 
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