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https://issues.apache.org/jira/browse/HBASE-10278?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13979439#comment-13979439
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Jonathan Hsieh commented on HBASE-10278:
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Currently trunk has some correctness problems when running the ITMTTR (having
to do with killing the rs hosting meta).
However running trunk and a modified version with this patch applied and on by
default we see significantly worse recovery time when the target RS is killed.
{code}
kill master kill rs
move regions
AVE,STD 99 AVE,STD 99.99 AVE,STD 99 AVE,STD 99.99
AVE,STD 99 AVE,STD 99.99
mhlog admin 18302.5 122.8 18302.5 122.8 2.1 0.3 51.9 10.4
2.0 0.0 34.2 7.6
put 5.1 0.3 117.9 95.3 5.1 0.3 37647.2 9888.0
5.6 0.5 169.4 30.3
scan 2.0 0.0 24.1 15.7 3.7 0.9 36131.2 13245.5
2.0 0.0 45.2 14.7
trunk admin 18557.3 357.2 18557.3 357.2 2.1 0.3 41.8 7.2
2.0 0.0 31.7 4.7
put 5.4 0.6 79.4 92.0 5.1 0.3 735.2 673.7
5.0 0.0 130.4 13.9
scan 2.0 0.0 27.0 15.8 2.4 0.7 165.7 138.3
2.0 0.5 39.9 9.4
{code}
> Provide better write predictability
> -----------------------------------
>
> Key: HBASE-10278
> URL: https://issues.apache.org/jira/browse/HBASE-10278
> Project: HBase
> Issue Type: New Feature
> Reporter: Himanshu Vashishtha
> Assignee: Himanshu Vashishtha
> Attachments: 10278-trunk-v2.1.patch, 10278-trunk-v2.1.patch,
> 10278-wip-1.1.patch, Multiwaldesigndoc.pdf, SwitchWriterFlow.pptx
>
>
> Currently, HBase has one WAL per region server.
> Whenever there is any latency in the write pipeline (due to whatever reasons
> such as n/w blip, a node in the pipeline having a bad disk, etc), the overall
> write latency suffers.
> Jonathan Hsieh and I analyzed various approaches to tackle this issue. We
> also looked at HBASE-5699, which talks about adding concurrent multi WALs.
> Along with performance numbers, we also focussed on design simplicity,
> minimum impact on MTTR & Replication, and compatibility with 0.96 and 0.98.
> Considering all these parameters, we propose a new HLog implementation with
> WAL Switching functionality.
> Please find attached the design doc for the same. It introduces the WAL
> Switching feature, and experiments/results of a prototype implementation,
> showing the benefits of this feature.
> The second goal of this work is to serve as a building block for concurrent
> multiple WALs feature.
> Please review the doc.
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