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Posted to commits@cassandra.apache.org by "Jonathan Ellis (JIRA)" <ji...@apache.org> on 2014/02/28 17:50:20 UTC
[jira] [Comment Edited] (CASSANDRA-6746) Reads have a slow ramp up
in speed
[ https://issues.apache.org/jira/browse/CASSANDRA-6746?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13915966#comment-13915966 ]
Jonathan Ellis edited comment on CASSANDRA-6746 at 2/28/14 4:48 PM:
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bq. On compaction we DONTNEED the replacement sstable.
-No, we don't-
You're right, this is also governed by populate_io_cache_on_flush. Now I wonder if that's deliberate or an oversight.
was (Author: jbellis):
bq. On compaction we DONTNEED the replacement sstable.
No, we don't.
> Reads have a slow ramp up in speed
> ----------------------------------
>
> Key: CASSANDRA-6746
> URL: https://issues.apache.org/jira/browse/CASSANDRA-6746
> Project: Cassandra
> Issue Type: Bug
> Components: Core
> Reporter: Ryan McGuire
> Assignee: Benedict
> Labels: performance
> Fix For: 2.1 beta2
>
> Attachments: 2.1_vs_2.0_read.png, cassandra-2.0-bdplab-trial-fincore.tar.bz2, cassandra-2.1-bdplab-trial-fincore.tar.bz2
>
>
> On a physical four node cluister I am doing a big write and then a big read. The read takes a long time to ramp up to respectable speeds.
> !2.1_vs_2.0_read.png!
> [See data here|http://ryanmcguire.info/ds/graph/graph.html?stats=stats.2.1_vs_2.0_vs_1.2.retry1.json&metric=interval_op_rate&operation=stress-read&smoothing=1]
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