You are viewing a plain text version of this content. The canonical link for it is here.
Posted to commits@cassandra.apache.org by "ZhaoYang (JIRA)" <ji...@apache.org> on 2018/03/06 02:06:00 UTC
[jira] [Comment Edited] (CASSANDRA-14292) Batch commitlog
performance regression in 3.0.16
[ https://issues.apache.org/jira/browse/CASSANDRA-14292?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16387146#comment-16387146 ]
ZhaoYang edited comment on CASSANDRA-14292 at 3/6/18 2:05 AM:
--------------------------------------------------------------
| [3.0|https://github.com/jasonstack/cassandra/commits/CASSANDRA-14292-3.0] | unit running] | dtest running |
Changes:
1. Set `syncRequested` to true in {{BatchCommitLogService.maybeWaitForSync}}
2. Added unit test to verify batch CL sync and shutdown immediately
was (Author: jasonstack):
| [3.0|https://github.com/jasonstack/cassandra/commits/CASSANDRA-14292-3.0] | [unit|https://circleci.com/gh/jasonstack/cassandra/716] | dtest running |
Changes:
1. Set `syncRequested` to true in {{BatchCommitLogService.maybeWaitForSync}}
2. Added unit test to verify batch CL sync and shutdown immediately
> Batch commitlog performance regression in 3.0.16
> ------------------------------------------------
>
> Key: CASSANDRA-14292
> URL: https://issues.apache.org/jira/browse/CASSANDRA-14292
> Project: Cassandra
> Issue Type: Bug
> Reporter: ZhaoYang
> Assignee: ZhaoYang
> Priority: Major
> Fix For: 3.0.x
>
>
> Prior to CASSANDRA-13987, in batch commitlog mode, commitlog will be synced to disk right after mutation comes.
> * haveWork semaphore is released in BatchCommitLogService.maybeWaitForSync
> * AbstractCommitlogService will continue and sync to disk
> After C-13987, it makes a branch for chain maker flush more frequently in periodic mode. To make sure in batch mode CL still flushes immediately, it added {{syncRequested}} flag.
> Unfortunately, in 3.0 branch, this flag is not being set to true when mutation is waiting.
> So in AbstractCommitlogService, it will not execute the CL sync branch until it reaches sync window(2ms)..
> {code:java|title=AbstractCommitLogService.java}
> if (lastSyncedAt + syncIntervalMillis <= pollStarted || shutdown || syncRequested)
> {
> // in this branch, we want to flush the commit log to disk
> syncRequested = false;
> commitLog.sync(shutdown, true);
> lastSyncedAt = pollStarted;
> syncComplete.signalAll();
> }
> else
> {
> // in this branch, just update the commit log sync headers
> commitLog.sync(false, false);
> }
> {code}
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
---------------------------------------------------------------------
To unsubscribe, e-mail: commits-unsubscribe@cassandra.apache.org
For additional commands, e-mail: commits-help@cassandra.apache.org