[
https://issues.apache.org/jira/browse/HBASE-8755?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13829631#comment-13829631
]
Feng Honghua commented on HBASE-8755:
-------------------------------------
[~stack] : I fixed the downgrade for 5 threads and below are the test result,
the write throughput capacity after tuning is *about 3.5 times* of the one
before tuning while keeping the perf is almost equal when thread number is <=
5. (for protobuf/test compatibility reason I based on hbase trunk 0.97 r1516083)
{code}
for i in 1 3 5 10 25 50 100 200; do
for j in 1; do
./bin/hbase
org.apache.hadoop.hbase.regionserver.wal.HLogPerformanceEvaluation -path
/user/h_fenghonghua/new-thread-v2/ -verify -threads "${i}" -iterations 1000000
-keySize 50 -valueSize 100 &> log-patch"${i}"."${j}".txt;
grep "Summary: " log-patch"${i}"."${j}".txt
done;
done
{code}
||threads||time-without-patch||ops-without-patch||time-with-patch||ops-with-patch||ops-diff||
|1|582|1716|630|1586|-7.5%|
|3|943|3179|951|3153|-0.8%|
|5|820|6091|847|5899|-3.1%|
|10|1141|8760|983|10166|+16%|
|25|1920|13019|1286|19426|+49.2%|
|50|3334|14995|1627|30715|+104.8%|
|100|5312|18824|1925|51943|+185%|
|200|11022|18144|3229|61922|+241.2%|
[~jmspaggi] : I attached patches for latest trunk (HBASE-8755-trunk-v4.patch)
and for the last 0.96 (HBASE-8755-0.96-v0.patch). Thanks very much if you can
run similar comparison perf tests, and any issue please feel free to raise :-)
> A new write thread model for HLog to improve the overall HBase write
> throughput
> -------------------------------------------------------------------------------
>
> Key: HBASE-8755
> URL: https://issues.apache.org/jira/browse/HBASE-8755
> Project: HBase
> Issue Type: Improvement
> Components: Performance, wal
> Reporter: Feng Honghua
> Assignee: stack
> Priority: Critical
> Attachments: 8755trunkV2.txt, HBASE-8755-0.94-V0.patch,
> HBASE-8755-0.94-V1.patch, HBASE-8755-0.96-v0.patch,
> HBASE-8755-trunk-V0.patch, HBASE-8755-trunk-V1.patch,
> HBASE-8755-trunk-v4.patch
>
>
> In current write model, each write handler thread (executing put()) will
> individually go through a full 'append (hlog local buffer) => HLog writer
> append (write to hdfs) => HLog writer sync (sync hdfs)' cycle for each write,
> which incurs heavy race condition on updateLock and flushLock.
> The only optimization where checking if current syncTillHere > txid in
> expectation for other thread help write/sync its own txid to hdfs and
> omitting the write/sync actually help much less than expectation.
> Three of my colleagues(Ye Hangjun / Wu Zesheng / Zhang Peng) at Xiaomi
> proposed a new write thread model for writing hdfs sequence file and the
> prototype implementation shows a 4X improvement for throughput (from 17000 to
> 70000+).
> I apply this new write thread model in HLog and the performance test in our
> test cluster shows about 3X throughput improvement (from 12150 to 31520 for 1
> RS, from 22000 to 70000 for 5 RS), the 1 RS write throughput (1K row-size)
> even beats the one of BigTable (Precolator published in 2011 says Bigtable's
> write throughput then is 31002). I can provide the detailed performance test
> results if anyone is interested.
> The change for new write thread model is as below:
> 1> All put handler threads append the edits to HLog's local pending buffer;
> (it notifies AsyncWriter thread that there is new edits in local buffer)
> 2> All put handler threads wait in HLog.syncer() function for underlying
> threads to finish the sync that contains its txid;
> 3> An single AsyncWriter thread is responsible for retrieve all the buffered
> edits in HLog's local pending buffer and write to the hdfs
> (hlog.writer.append); (it notifies AsyncFlusher thread that there is new
> writes to hdfs that needs a sync)
> 4> An single AsyncFlusher thread is responsible for issuing a sync to hdfs
> to persist the writes by AsyncWriter; (it notifies the AsyncNotifier thread
> that sync watermark increases)
> 5> An single AsyncNotifier thread is responsible for notifying all pending
> put handler threads which are waiting in the HLog.syncer() function
> 6> No LogSyncer thread any more (since there is always
> AsyncWriter/AsyncFlusher threads do the same job it does)
--
This message was sent by Atlassian JIRA
(v6.1#6144)
