Mailing-List: contact commits-help@cassandra.apache.org; run by ezmlm
Precedence: bulk
Reply-To: dev@cassandra.apache.org
Message-ID: <31721197.37561288979684781.JavaMail.jira@thor>
Date: Fri, 5 Nov 2010 13:54:44 -0400 (EDT)
From: "Jonathan Ellis (JIRA)" <jira@apache.org>
To: commits@cassandra.apache.org
Subject: [jira] Commented: (CASSANDRA-1470) use direct io for compaction
In-Reply-To: <23563671.30841283654613916.JavaMail.jira@thor>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit


    [ https://issues.apache.org/jira/browse/CASSANDRA-1470?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12928707#action_12928707 ] 

Jonathan Ellis commented on CASSANDRA-1470:
-------------------------------------------

Let's use exceptions rather than return flags in java code.

DIRAF copy/pastes a bunch of stuff unnecessarily (isEOF, the Mark class, probably more).  Probably we could not even need a separate class if we modifed BRAF to do alignment all the time (the performance impact would be basically negligible when doing non-direct i/o).

We're trying to keep platform-specific code in CLibrary, setDirectIO and the flags should go there.

> use direct io for compaction
> ----------------------------
>
>                 Key: CASSANDRA-1470
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-1470
>             Project: Cassandra
>          Issue Type: Improvement
>          Components: Core
>            Reporter: Jonathan Ellis
>            Assignee: Pavel Yaskevich
>             Fix For: 0.6.7, 0.7.1
>
>         Attachments: 1470-v2.txt, 1470.txt, CASSANDRA-1470-for-0.6.patch, CASSANDRA-1470-v2.patch, CASSANDRA-1470-v3-0.7-with-LastErrorException-support.patch, CASSANDRA-1470-v4-for-0.7.patch, CASSANDRA-1470.patch, use.DirectIORandomAccessFile.for.commitlog.against.1022235.patch
>
>
> When compaction scans through a group of sstables, it forces the data in the os buffer cache being used for hot reads, which can have a dramatic negative effect on performance.

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