[
https://issues.apache.org/jira/browse/HDFS-941?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13050609#comment-13050609
]
Konstantin Shvachko commented on HDFS-941:
------------------------------------------
> I think it is reasonable to run tests against the latest patch and make sure
> there is no regression in performance.
This is exactly what I asked. That is to run DFSIO on 5-node cluster with and
without the *new* patch.
Here is the command I propose to run for 5 nodes (should have nrFile <=
nrNodes).
{code}
TestDFSIO -read -fileSize 10GB -nrFiles 5
{code}
You can run -write first to generate data.
I think this will be representative enough.
> it failed to reject the null hypothesis
Great analysis Todd, I am truly impressed. Does everything run on one node? Is
there any inter-DN communication then? Also with 128 MB file everything is in
RAM, not sure what it measures.
> Uncommitting now may do more harm than good.
If my concerns can be addressed without uncommitting then I can hold on to
that. Please confirm somebody is doing it.
> Datanode xceiver protocol should allow reuse of a connection
> ------------------------------------------------------------
>
> Key: HDFS-941
> URL: https://issues.apache.org/jira/browse/HDFS-941
> Project: Hadoop HDFS
> Issue Type: Improvement
> Components: data-node, hdfs client
> Affects Versions: 0.22.0
> Reporter: Todd Lipcon
> Assignee: bc Wong
> Fix For: 0.22.0
>
> Attachments: 941.22.txt, 941.22.txt, 941.22.v2.txt, 941.22.v3.txt,
> HDFS-941-1.patch, HDFS-941-2.patch, HDFS-941-3.patch, HDFS-941-3.patch,
> HDFS-941-4.patch, HDFS-941-5.patch, HDFS-941-6.22.patch, HDFS-941-6.patch,
> HDFS-941-6.patch, HDFS-941-6.patch, fix-close-delta.txt, hdfs-941.txt,
> hdfs-941.txt, hdfs-941.txt, hdfs-941.txt, hdfs941-1.png
>
>
> Right now each connection into the datanode xceiver only processes one
> operation.
> In the case that an operation leaves the stream in a well-defined state (eg a
> client reads to the end of a block successfully) the same connection could be
> reused for a second operation. This should improve random read performance
> significantly.
--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira
