[
https://issues.apache.org/jira/browse/CASSANDRA-6746?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13977235#comment-13977235
]
Benedict commented on CASSANDRA-6746:
-------------------------------------
I've updated the ticket to a minor improvement and moved it to no-release for
now, as CASSANDRA-6916 looks to solve the regression; not sure if you still
want to investigate the read-ahead changes you were looking at still though as
an improvement, [~xedin]? If not I'll resolve the ticket.
> Reads have a slow ramp up in speed
> ----------------------------------
>
> Key: CASSANDRA-6746
> URL: https://issues.apache.org/jira/browse/CASSANDRA-6746
> Project: Cassandra
> Issue Type: Improvement
> Components: Core
> Reporter: Ryan McGuire
> Assignee: Benedict
> Priority: Minor
> Labels: performance
> Attachments: 2.1_vs_2.0_read.png, 6746-buffered-io-tweaks.png,
> 6746-patched.png, 6746.blockdev_setra.full.png,
> 6746.blockdev_setra.zoomed.png, 6746.buffered_io_tweaks.logs.tar.gz,
> 6746.buffered_io_tweaks.write-flush-compact-mixed.png,
> 6746.buffered_io_tweaks.write-read-flush-compact.png, 6746.txt,
> buffered-io-tweaks.patch, 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]
--
This message was sent by Atlassian JIRA
(v6.2#6252)
