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https://issues.apache.org/jira/browse/HBASE-11492?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14061425#comment-14061425
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Hudson commented on HBASE-11492:
--------------------------------
FAILURE: Integrated in HBase-0.98-on-Hadoop-1.1 #378 (See
[https://builds.apache.org/job/HBase-0.98-on-Hadoop-1.1/378/])
HBASE-11492 Hadoop configuration overrides some ipc parameters including
tcpNoDelay (Nicolas Liochon) (apurtell: rev
9cb234104d63b1a96232e821ad0cbbb516aeae84)
* hbase-server/src/main/java/org/apache/hadoop/hbase/ipc/SimpleRpcScheduler.java
*
hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/wal/TestHLog.java
* hbase-server/src/main/java/org/apache/hadoop/hbase/ipc/FifoRpcScheduler.java
*
hbase-server/src/test/java/org/apache/hadoop/hbase/TestFullLogReconstruction.java
* hbase-server/src/main/java/org/apache/hadoop/hbase/ipc/RpcServer.java
* hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegion.java
> Hadoop configuration overrides some ipc parameters including tcpNoDelay
> -----------------------------------------------------------------------
>
> Key: HBASE-11492
> URL: https://issues.apache.org/jira/browse/HBASE-11492
> Project: HBase
> Issue Type: Bug
> Components: regionserver
> Affects Versions: 0.98.0, 0.99.0
> Reporter: Nicolas Liochon
> Assignee: Nicolas Liochon
> Priority: Critical
> Fix For: 0.99.0, 0.98.4, 2.0.0
>
> Attachments: 11492.v1.patch, 11492.v1.withp1.patch,
> 11492.v2-0.98.patch, 11492.v2.patch, 11492.v2.patch
>
>
> There is an option to set tcpNoDelay, defaulted to true, but the socket
> channel is actually not changed. As a consequence, the server works with
> nagle enabled. This leads to very degraded behavior when a single connection
> is shared between threads. We enter into conflicts with nagle and tcp delayed
> ack.
> Here is an example of performance with the PE tool plus HBASE-11491:
> {noformat}
> oneCon #client sleep exeTime (seconds)
> avg latency, sleep excluded (microseconds)
> true 1 0 31
> 310
> false 1 0 31
> 310
> true 2 0 50
> 500
> false 2 0 31
> 310
> true 2 5 488 (including 200s sleeping)
> 2880
> false 2 5 246 (including 200s sleeping)
> 460
> {noformat}
> The latency is multiple by 5 (2880 vs 460) when the connection is shared.
> This is the delayed ack kicking in. This can be fixed by really using tcp no
> delay.
> Any application sharing the tcp connection between threads has the issue.
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