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https://issues.apache.org/jira/browse/HBASE-10010?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13831195#comment-13831195
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Liang Xie commented on HBASE-10010:
-----------------------------------
Oh, [[email protected]], very very thanks for pointing out this.
After a looking at deeper code, i think the key is SequenceFile Class under
hadoop-common project, see (i extracted below code from cdh4.1.1 modified
version)
{code}
/** Write and flush the file header. */
private void writeFileHeader()
throws IOException {
out.write(VERSION);
Text.writeString(out, keyClass.getName());
Text.writeString(out, valClass.getName());
out.writeBoolean(this.isCompressed());
out.writeBoolean(this.isBlockCompressed());
if (this.isCompressed()) {
Text.writeString(out, (codec.getClass()).getName());
}
this.metadata.write(out);
out.write(sync); // write the sync bytes
out.flush(); // flush header
}
{code}
yes, i agree with you now that we can just issue "sync" api, it should be
enough, since i did a "svn blame" on SequenceFile.java, it shows this
writeFileHeader() method was added long long time ago.
I had uploaded the simplified patch against 0.94 branch and trunk, could you
guys help to look again? thanks!
[[email protected]],
[[email protected]],[~lhofhansl],[[email protected]]
> eliminate the put latency spike on the new log file beginning
> -------------------------------------------------------------
>
> Key: HBASE-10010
> URL: https://issues.apache.org/jira/browse/HBASE-10010
> Project: HBase
> Issue Type: Improvement
> Components: regionserver
> Affects Versions: 0.94.13
> Reporter: Liang Xie
> Assignee: Liang Xie
> Attachments: HBase-10010-0.94-v2.txt, HBase-10010-0.94-v3.txt,
> HBase-10010-0.94.txt, HBase-10010-trunk-v2.txt, HBase-10010-trunk.txt
>
>
> In deed, the original finding came from fb, see HBASE-6813 for detailed
> discussion.
> Through this improvement doesn't expect obvious gain on 95th or 99th latency,
> it still could make the response time more stable to me.
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