[
https://issues.apache.org/jira/browse/HBASE-16890?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15604290#comment-15604290
]
Duo Zhang commented on HBASE-16890:
-----------------------------------
No magic.
{code}
protected synchronized int flushBuffer(boolean keep,
boolean flushPartial) throws IOException {
int bufLen = count;
int partialLen = bufLen % sum.getBytesPerChecksum();
int lenToFlush = flushPartial ? bufLen : bufLen - partialLen;
if (lenToFlush != 0) {
writeChecksumChunks(buf, 0, lenToFlush);
if (!flushPartial || keep) {
count = partialLen;
System.arraycopy(buf, bufLen - count, buf, 0, count);
} else {
count = 0;
}
}
// total bytes left minus unflushed bytes left
return count - (bufLen - lenToFlush);
}
{code}
And in DFSOutputStream.flushOrSync
{code}
// flush checksum buffer, but keep checksum buffer intact if we do not
// need to end the current block
int numKept = flushBuffer(!endBlock, true);
{code}
Just a simple copy...
> Analyze the performance of AsyncWAL and fix the same
> ----------------------------------------------------
>
> Key: HBASE-16890
> URL: https://issues.apache.org/jira/browse/HBASE-16890
> Project: HBase
> Issue Type: Sub-task
> Components: wal
> Affects Versions: 2.0.0
> Reporter: ramkrishna.s.vasudevan
> Assignee: ramkrishna.s.vasudevan
> Fix For: 2.0.0
>
> Attachments: contention.png, contention_defaultWAL.png
>
>
> Tests reveal that AsyncWAL under load in single node cluster performs slower
> than the Default WAL. This task is to analyze and see if we could fix it.
> See some discussions in the tail of JIRA HBASE-15536.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
