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https://issues.apache.org/jira/browse/CASSANDRA-658?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12797616#action_12797616
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Hudson commented on CASSANDRA-658:
----------------------------------
Integrated in Cassandra #316 (See
[http://hudson.zones.apache.org/hudson/job/Cassandra/316/])
replace sharded row locks with column-level locking
patch by jbellis; tested by Brandon Williams for
use throughput and op count instead of size and column count to determine when
to flush, greatly reducing the amount of synchronization required to insert
patch by jbellis; tested by Brandon Williams for
> Hinted Handoff CF contention
> ----------------------------
>
> Key: CASSANDRA-658
> URL: https://issues.apache.org/jira/browse/CASSANDRA-658
> Project: Cassandra
> Issue Type: Bug
> Components: Core
> Affects Versions: 0.5
> Environment: debian lenny amd64 OpenJDK 64-Bit Server VM (build
> 1.6.0_0-b11, mixed mode)
> Reporter: Brandon Williams
> Assignee: Jonathan Ellis
> Fix For: 0.9
>
> Attachments:
> 0001-use-throughput-and-op-count-instead-of-size-and-column.txt,
> 0002-replace-sharded-row-locks-with-column-level-locking.txt,
> 0003-r-m-unused-code.txt
>
>
> Hinted handoff causes a lot of contention on the HH CF, causing insert speed
> to massively drop. Most of the row mutation stage threads end up blocking on
> each other at Memtable.resolve. This is because HH sends the hint to the
> closest node, which will always be the node handling the write.
> To reproduce: start a cluster with even InitialTokens, and begin a constant
> stream of writes to one node, with an even key distribution. (I used 4 nodes
> and stress.py in random mode.) Take a node down, and the insert rate begin
> to drop, eventually settling between 100-300/s and sustaining there.
> Bringing the down node back up will restore the original insert rate.
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