[
https://issues.apache.org/jira/browse/LUCENE-4864?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Uwe Schindler updated LUCENE-4864:
----------------------------------
Description:
On LUCENE-4848 a new directory implementation was proposed that uses
AsyncFileChannel to make a sync-less directory implementation (only needed for
IndexInput). The problem on Windows is that positional reads are impossible
without overlapping (async) I/O, so FileChannel in the JDK has to syncronize
all reads, because they consist of an atomic seek and atomic read.
AsyncFSDirectoty would not have this issue, but has to take care of thread
management, because you need a separate thread to get notified when the read is
done. This involves overhead, but might still be better than the
synchronization.
was:
On LUCENE-4848 a new directory implementation was proposed that uses
AsyncFileChannel to make a sync-less directory implementation (only needed for
IndexInput). The problem on Windows is that positional reads are impossible
without overlapping (async I/O), so FileChannel in the JDK has to syncronize
all reads, because they consist of an atomic seek and atomic read.
AsyncFSDirectoty would not have this issue, but has to take care of thread
management.
> Add AsyncFSDirectory to work around Windows issues with NIOFS (Lucene 5.0
> only)
> -------------------------------------------------------------------------------
>
> Key: LUCENE-4864
> URL: https://issues.apache.org/jira/browse/LUCENE-4864
> Project: Lucene - Core
> Issue Type: Improvement
> Components: core/store
> Reporter: Uwe Schindler
>
> On LUCENE-4848 a new directory implementation was proposed that uses
> AsyncFileChannel to make a sync-less directory implementation (only needed
> for IndexInput). The problem on Windows is that positional reads are
> impossible without overlapping (async) I/O, so FileChannel in the JDK has to
> syncronize all reads, because they consist of an atomic seek and atomic read.
> AsyncFSDirectoty would not have this issue, but has to take care of thread
> management, because you need a separate thread to get notified when the read
> is done. This involves overhead, but might still be better than the
> synchronization.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
