On Mon, Nov 30, 2015 at 2:31 PM, Bryan Beaudreault <bbeaudrea...@hubspot.com > wrote:
> The rollback seems to have mostly solved the issue for one of our clusters, > but another one is still seeing long increment times: > > "slowIncrementCount": 52080, > "Increment_num_ops": 325236,"Increment_min": 1,"Increment_max": 6162," > Increment_mean": 465.68678129112396,"Increment_median": 216," > Increment_75th_percentile": 450.25,"Increment_95th_percentile": > 1052.6499999999999,"Increment_99th_percentile": 1635.2399999999998 > > > Any ideas if there are other changes that may be causing a performance > regression for increments between CDH4.7.1 and CDH5.3.8? > > > No. Post a thread dump Bryan and it might prompt something. St.Ack > > On Mon, Nov 30, 2015 at 4:13 PM Stack <st...@duboce.net> wrote: > > > On Mon, Nov 30, 2015 at 12:54 PM, Bryan Beaudreault < > > bbeaudrea...@hubspot.com> wrote: > > > > > Should this be added as a known issue in the CDH or hbase > documentation? > > It > > > was a severe performance hit for us, all of our regionservers were > > sitting > > > at a few thousand queued requests. > > > > > > > > Let me take care of that. > > St.Ack > > > > > > > > > On Mon, Nov 30, 2015 at 3:53 PM Bryan Beaudreault < > > > bbeaudrea...@hubspot.com> > > > wrote: > > > > > > > Yea, they are all over the place and called from client and > coprocessor > > > > code. We ended up having no other option but to rollback, and aside > > from > > > a > > > > few NoSuchMethodErrors due to API changes (Put#add vs Put#addColumn), > > it > > > > seems to be working and fixing our problem. > > > > > > > > On Mon, Nov 30, 2015 at 3:47 PM Stack <st...@duboce.net> wrote: > > > > > > > >> Rollback is untested. No fix in 5.5. I was going to work on this > now. > > > >> Where > > > >> are your counters Bryan? In their own column family or scattered > about > > > in > > > >> a > > > >> row with other Cell types? > > > >> St.Ack > > > >> > > > >> On Mon, Nov 30, 2015 at 10:28 AM, Bryan Beaudreault < > > > >> bbeaudrea...@hubspot.com> wrote: > > > >> > > > >> > Is there any update to this? We just upgraded all of our > production > > > >> > clusters from CDH4 to CDH5.4.7 and, not seeing this JIRA listed in > > the > > > >> > known issues, did not not about this. Now we are seeing > perfomance > > > >> issues > > > >> > across all clusters, as we make heavy use of increments. > > > >> > > > > >> > Can we roll forward to CDH5.5 to fix? Or is our only hope to roll > > back > > > >> to > > > >> > CDH 5.3.1 (if that is possible)? > > > >> > > > > >> > > > > >> > On Thu, Sep 24, 2015 at 5:06 AM 鈴木俊裕 <brfrn...@gmail.com> wrote: > > > >> > > > > >> > > Thank you St.Ack! > > > >> > > > > > >> > > I would like to follow the ticket. > > > >> > > > > > >> > > Toshihiro Suzuki > > > >> > > > > > >> > > 2015-09-22 14:14 GMT+09:00 Stack <st...@duboce.net>: > > > >> > > > > > >> > > > Back to this problem. Simple tests confirm that as is, the > > > >> > > > single-queue-backed MVCC instance can slow Region ops if some > > > other > > > >> row > > > >> > > is > > > >> > > > slow to complete. In particular Increment, checkAndPut, and > > batch > > > >> > > mutations > > > >> > > > are effected. I opened HBASE-14460 to start in on a fix up. > Lets > > > >> see if > > > >> > > we > > > >> > > > can somehow scope mvcc to row or at least shard mvcc so not > all > > > >> Region > > > >> > > ops > > > >> > > > are paused. > > > >> > > > > > > >> > > > St.Ack > > > >> > > > > > > >> > > > > > > >> > > > On Mon, Sep 14, 2015 at 4:15 AM, 鈴木俊裕 <brfrn...@gmail.com> > > wrote: > > > >> > > > > > > >> > > > > > Thank you for the below reasoning (with accompanying > helpful > > > >> > > diagram). > > > >> > > > > > Makes sense. Let me hack up a test case to help with the > > > >> > > illustration. > > > >> > > > It > > > >> > > > > > is as though the mvcc should be scoped to a row only... > > Writes > > > >> > > against > > > >> > > > > > other rows should not hold up my read of my row. Tag an > mvcc > > > >> with a > > > >> > > > 'row' > > > >> > > > > > scope so we can see which on-going writes pertain to > current > > > >> > > operation? > > > >> > > > > Thank you St.Ack! I think this approach would work. > > > >> > > > > > > > >> > > > > > You need to read back the increment and have it be > 'correct' > > > at > > > >> > > > increment > > > >> > > > > > time? > > > >> > > > > Yes, we need it. > > > >> > > > > > > > >> > > > > I would like to help if there is anything I can do. > > > >> > > > > > > > >> > > > > Thanks, > > > >> > > > > Toshihiro Suzuki > > > >> > > > > > > > >> > > > > > > > >> > > > > 2015-09-13 14:11 GMT+09:00 Stack <st...@duboce.net>: > > > >> > > > > > > > >> > > > > > Thank you for the below reasoning (with accompanying > helpful > > > >> > > diagram). > > > >> > > > > > Makes sense. Let me hack up a test case to help with the > > > >> > > illustration. > > > >> > > > It > > > >> > > > > > is as though the mvcc should be scoped to a row only... > > Writes > > > >> > > against > > > >> > > > > > other rows should not hold up my read of my row. Tag an > mvcc > > > >> with a > > > >> > > > 'row' > > > >> > > > > > scope so we can see which on-going writes pertain to > current > > > >> > > operation? > > > >> > > > > > > > > >> > > > > > You need to read back the increment and have it be > 'correct' > > > at > > > >> > > > increment > > > >> > > > > > time? > > > >> > > > > > > > > >> > > > > > (This is a good one) > > > >> > > > > > > > > >> > > > > > Thank you Toshihiro Suzuki > > > >> > > > > > St.Ack > > > >> > > > > > > > > >> > > > > > On Sat, Sep 12, 2015 at 8:09 AM, 鈴木俊裕 <brfrn...@gmail.com > > > > > >> wrote: > > > >> > > > > > > > > >> > > > > > > St.Ack, > > > >> > > > > > > > > > >> > > > > > > Thank you for your response. > > > >> > > > > > > > > > >> > > > > > > Why I make out that "A region lock (not a row lock) > seems > > to > > > >> > occur > > > >> > > in > > > >> > > > > > > waitForPreviousTransactionsComplete()" is as follows: > > > >> > > > > > > > > > >> > > > > > > A increment operation has 3 procedures for MVCC. > > > >> > > > > > > > > > >> > > > > > > 1. mvcc.waitForPreviousTransactionsComplete(); > > > >> > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > >> > > > > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > https://github.com/cloudera/hbase/blob/cdh5.4.5-release/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegion.java#L6712 > > > >> > > > > > > > > > >> > > > > > > 2. w = mvcc.beginMemstoreInsertWithSeqNum(mvccNum); > > > >> > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > >> > > > > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > https://github.com/cloudera/hbase/blob/cdh5.4.5-release/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegion.java#L6721 > > > >> > > > > > > > > > >> > > > > > > 3. mvcc.completeMemstoreInsertWithSeqNum(w, walKey); > > > >> > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > >> > > > > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > https://github.com/cloudera/hbase/blob/cdh5.4.5-release/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegion.java#L6893 > > > >> > > > > > > > > > >> > > > > > > > > > >> > > > > > > I think that MultiVersionConsistencyControl's writeQueue > > can > > > >> > cause > > > >> > > a > > > >> > > > > > region > > > >> > > > > > > lock. > > > >> > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > >> > > > > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > https://github.com/cloudera/hbase/blob/cdh5.4.5-release/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/MultiVersionConsistencyControl.java#L42-L43 > > > >> > > > > > > > > > >> > > > > > > > > > >> > > > > > > Step 2 adds to a WriteEntry to writeQueue. > > > >> > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > >> > > > > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > https://github.com/cloudera/hbase/blob/cdh5.4.5-release/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/MultiVersionConsistencyControl.java#L102-L108 > > > >> > > > > > > > > > >> > > > > > > Step 3 removes the WriteEntry from writeQueue. > > > >> > > > > > > > > > >> > > > > > > completeMemstoreInsertWithSeqNum(w, walKey) -> > > > >> > > > > > > waitForPreviousTransactionsComplete(e) -> > > advanceMemstore(w) > > > >> > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > >> > > > > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > https://github.com/cloudera/hbase/blob/cdh5.4.5-release/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/MultiVersionConsistencyControl.java#L127 > > > >> > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > >> > > > > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > https://github.com/cloudera/hbase/blob/cdh5.4.5-release/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/MultiVersionConsistencyControl.java#L235 > > > >> > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > >> > > > > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > https://github.com/cloudera/hbase/blob/cdh5.4.5-release/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/MultiVersionConsistencyControl.java#L160 > > > >> > > > > > > > > > >> > > > > > > Step 1 adds a WriteEntry w in beginMemstoreInsert() to > > > >> writeQueue > > > >> > > and > > > >> > > > > > waits > > > >> > > > > > > until writeQueue is empty or writeQueue.getFirst() == w. > > > >> > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > >> > > > > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > https://github.com/cloudera/hbase/blob/cdh5.4.5-release/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/MultiVersionConsistencyControl.java#L201-L204 > > > >> > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > >> > > > > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > https://github.com/cloudera/hbase/blob/cdh5.4.5-release/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/MultiVersionConsistencyControl.java#L206-L241 > > > >> > > > > > > > > > >> > > > > > > > > > >> > > > > > > I think when a handler thread is processing between > step 2 > > > and > > > >> > step > > > >> > > > 3, > > > >> > > > > > the > > > >> > > > > > > other handler threads can wait at step 1 until the > thread > > > >> > completes > > > >> > > > > step > > > >> > > > > > 3 > > > >> > > > > > > This is depicted as follows: > > > >> > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > >> > > > > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > https://gist.githubusercontent.com/brfrn169/cb4f2c157129330cd932/raw/86d6aae5667b0fe006b16fed80f1b0c4945c7fd0/region_lock.png > > > >> > > > > > > > > > >> > > > > > > > > > >> > > > > > > Actually, in the thread dump of our region server, many > > > >> handler > > > >> > > > threads > > > >> > > > > > > (RW.default.writeRpcServer.handler) wait at Step 1 > > > >> > > > > > > (waitForPreviousTransactionsComplete()). > > > >> > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > >> > > > > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > https://gist.githubusercontent.com/brfrn169/cb4f2c157129330cd932/raw/86d6aae5667b0fe006b16fed80f1b0c4945c7fd0/thread_dump.txt > > > >> > > > > > > > > > >> > > > > > > Many handler threads wait at this: > > > >> > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > >> > > > > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > https://github.com/cloudera/hbase/blob/cdh5.4.5-release/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/MultiVersionConsistencyControl.java#L224 > > > >> > > > > > > > > > >> > > > > > > > > > >> > > > > > > > Is it possible you are contending on a counter > > > post-upgrade? > > > >> > Is > > > >> > > it > > > >> > > > > > > > possible that all these threads are trying to get to > the > > > >> same > > > >> > row > > > >> > > > to > > > >> > > > > > > update > > > >> > > > > > > > it? Could the app behavior have changed? Or are you > > > >> thinking > > > >> > > > > increment > > > >> > > > > > > > itself has slowed significantly? > > > >> > > > > > > We have just upgraded HBase, not changed the app > behavior. > > > We > > > >> are > > > >> > > > > > thinking > > > >> > > > > > > increment itself has slowed significantly. > > > >> > > > > > > Before upgrading HBase, it was good throughput and > > latency. > > > >> > > > > > > Currently, to cope with this problem, we split the > regions > > > >> > finely. > > > >> > > > > > > > > > >> > > > > > > Thanks, > > > >> > > > > > > > > > >> > > > > > > Toshihiro Suzuki > > > >> > > > > > > > > > >> > > > > > > > > > >> > > > > > > 2015-09-09 15:29 GMT+09:00 Stack <st...@duboce.net>: > > > >> > > > > > > > > > >> > > > > > > > On Tue, Sep 8, 2015 at 10:22 PM, 鈴木俊裕 < > > brfrn...@gmail.com > > > > > > > >> > > wrote: > > > >> > > > > > > > > > > >> > > > > > > > > Ted, > > > >> > > > > > > > > > > > >> > > > > > > > > Thank you for your response. > > > >> > > > > > > > > > > > >> > > > > > > > > I uploaded the complete stack trace to Gist. > > > >> > > > > > > > > > > > >> > > > > > > > > > https://gist.github.com/brfrn169/cb4f2c157129330cd932 > > > >> > > > > > > > > > > > >> > > > > > > > > > > > >> > > > > > > > > I think that increment operation works as follows: > > > >> > > > > > > > > > > > >> > > > > > > > > 1. get row lock > > > >> > > > > > > > > 2. mvcc.waitForPreviousTransactionsComplete() // > wait > > > for > > > >> all > > > >> > > > prior > > > >> > > > > > > MVCC > > > >> > > > > > > > > transactions to finish > > > >> > > > > > > > > 3. mvcc.beginMemstoreInsertWithSeqNum() // start a > > > >> > transaction > > > >> > > > > > > > > 4. get previous values > > > >> > > > > > > > > 5. create KVs > > > >> > > > > > > > > 6. write to Memstore > > > >> > > > > > > > > 7. write to WAL > > > >> > > > > > > > > 8. release row lock > > > >> > > > > > > > > 9. mvcc.completeMemstoreInsertWithSeqNum() // > complete > > > the > > > >> > > > > > transaction > > > >> > > > > > > > > > > > >> > > > > > > > > A instance of MultiVersionConsistencyControl has a > > > pending > > > >> > > queue > > > >> > > > of > > > >> > > > > > > > writes > > > >> > > > > > > > > named writeQueue. > > > >> > > > > > > > > Step 2 puts a WriteEntry w to writeQueue and waits > > until > > > >> > > > writeQueue > > > >> > > > > > is > > > >> > > > > > > > > empty or writeQueue.getFirst() == w. > > > >> > > > > > > > > Step 3 puts a WriteEntry to writeQueue and step 9 > > > removes > > > >> the > > > >> > > > > > > WriteEntry > > > >> > > > > > > > > from writeQueue. > > > >> > > > > > > > > > > > >> > > > > > > > > I think that when a handler thread is processing > > between > > > >> > step 2 > > > >> > > > and > > > >> > > > > > > step > > > >> > > > > > > > 9, > > > >> > > > > > > > > the other handler threads can wait until the thread > > > >> completes > > > >> > > > step > > > >> > > > > 9. > > > >> > > > > > > > > > > > >> > > > > > > > > > > > >> > > > > > > > That is right. We need to read, after all outstanding > > > >> updates > > > >> > are > > > >> > > > > > done... > > > >> > > > > > > > because we need to read the latest update before we go > > to > > > >> > > > > > > modify/increment > > > >> > > > > > > > it. > > > >> > > > > > > > > > > >> > > > > > > > How do you make out this? > > > >> > > > > > > > > > > >> > > > > > > > "A region lock (not a row lock) seems to occur in > > > >> > > > > > > > waitForPreviousTransactionsComplete()." > > > >> > > > > > > > > > > >> > > > > > > > In 0.98.x we did this: > > > >> > > > > > > > > > > >> > > > > > > > > mvcc.completeMemstoreInsert(mvcc.beginMemstoreInsert()); > > > >> > > > > > > > > > > >> > > > > > > > ... and in 1.0 we do this: > > > >> > > > > > > > > > > >> > > > > > > > mvcc.waitForPreviousTransactionsComplete() which is > > > this.... > > > >> > > > > > > > > > > >> > > > > > > > + public void waitForPreviousTransactionsComplete() { > > > >> > > > > > > > + WriteEntry w = beginMemstoreInsert(); > > > >> > > > > > > > + waitForPreviousTransactionsComplete(w); > > > >> > > > > > > > + } > > > >> > > > > > > > > > > >> > > > > > > > The mvcc and region sequenceid were merged in 1.0 ( > > > >> > > > > > > > https://issues.apache.org/jira/browse/HBASE-8763). > > > Previous > > > >> > mvcc > > > >> > > > and > > > >> > > > > > > > region > > > >> > > > > > > > sequenceid would spin independent of each other. > Perhaps > > > >> this > > > >> > > > > > responsible > > > >> > > > > > > > for some slow down. > > > >> > > > > > > > > > > >> > > > > > > > That said, looking in your thread dump, we seem to be > > down > > > >> in > > > >> > the > > > >> > > > > Get. > > > >> > > > > > If > > > >> > > > > > > > you do a bunch of thread dumps in a row, where is the > > > >> > > lock-holding > > > >> > > > > > > thread? > > > >> > > > > > > > In Get or writing Increment... or waiting on sequence > > id? > > > >> > > > > > > > > > > >> > > > > > > > Is it possible you are contending on a counter > > > post-upgrade? > > > >> > Is > > > >> > > it > > > >> > > > > > > > possible that all these threads are trying to get to > the > > > >> same > > > >> > row > > > >> > > > to > > > >> > > > > > > update > > > >> > > > > > > > it? Could the app behavior have changed? Or are you > > > >> thinking > > > >> > > > > increment > > > >> > > > > > > > itself has slowed significantly? > > > >> > > > > > > > > > > >> > > > > > > > St.Ack > > > >> > > > > > > > > > > >> > > > > > > > > > > >> > > > > > > > > > > >> > > > > > > > > > > >> > > > > > > > > Thanks, > > > >> > > > > > > > > > > > >> > > > > > > > > Toshihiro Suzuki > > > >> > > > > > > > > > > > >> > > > > > > > > > > > >> > > > > > > > > 2015-09-09 0:05 GMT+09:00 Ted Yu < > yuzhih...@gmail.com > > >: > > > >> > > > > > > > > > > > >> > > > > > > > > > In HRegion#increment(), we lock the row (not > > region): > > > >> > > > > > > > > > > > > >> > > > > > > > > > try { > > > >> > > > > > > > > > rowLock = getRowLock(row); > > > >> > > > > > > > > > > > > >> > > > > > > > > > Can you pastebin the complete stack trace ? > > > >> > > > > > > > > > > > > >> > > > > > > > > > Thanks > > > >> > > > > > > > > > > > > >> > > > > > > > > > On Tue, Sep 8, 2015 at 2:01 AM, 鈴木俊裕 < > > > >> brfrn...@gmail.com> > > > >> > > > wrote: > > > >> > > > > > > > > > > > > >> > > > > > > > > > > Hi, > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > We upgraded our cluster from > CDH5.3.1(HBase0.98.6) > > > to > > > >> > > > > > > > > > CDH5.4.5(HBase1.0.0) > > > >> > > > > > > > > > > and we experience slowdown in increment > operation. > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > Here's an extract from thread dump of the > > > >> RegionServer of > > > >> > > our > > > >> > > > > > > > cluster: > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > Thread 68 > > > >> > > > > > > > (RW.default.writeRpcServer.handler=15,queue=5,port=60020): > > > >> > > > > > > > > > > State: BLOCKED > > > >> > > > > > > > > > > Blocked count: 21689888 > > > >> > > > > > > > > > > Waited count: 39828360 > > > >> > > > > > > > > > > Blocked on java.util.LinkedList@3474e4b2 > > > >> > > > > > > > > > > Blocked by 63 > > > >> > > > > > > > > > > > (RW.default.writeRpcServer.handler=10,queue=0,port=60020) > > > >> > > > > > > > > > > Stack: > > > >> > > > > > > > > > > java.lang.Object.wait(Native Method) > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > > >> > > > > > > > > > > > >> > > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > >> > > > > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > org.apache.hadoop.hbase.regionserver.MultiVersionConsistencyControl.waitForPreviousTransactionsComplete(MultiVersionConsistencyControl.java:224) > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > > >> > > > > > > > > > > > >> > > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > >> > > > > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > org.apache.hadoop.hbase.regionserver.MultiVersionConsistencyControl.waitForPreviousTransactionsComplete(MultiVersionConsistencyControl.java:203) > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > >> > > > > > > > > > >> > > > > > > > >> > > > > > >> > > > > org.apache.hadoop.hbase.regionserver.HRegion.increment(HRegion.java:6712) > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > > >> > > > > > > > > > > > >> > > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > >> > > > > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > org.apache.hadoop.hbase.regionserver.RSRpcServices.increment(RSRpcServices.java:501) > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > > >> > > > > > > > > > > > >> > > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > >> > > > > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > org.apache.hadoop.hbase.regionserver.RSRpcServices.doNonAtomicRegionMutation(RSRpcServices.java:570) > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > > >> > > > > > > > > > > > >> > > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > >> > > > > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > org.apache.hadoop.hbase.regionserver.RSRpcServices.multi(RSRpcServices.java:1901) > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > > >> > > > > > > > > > > > >> > > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > >> > > > > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > org.apache.hadoop.hbase.protobuf.generated.ClientProtos$ClientService$2.callBlockingMethod(ClientProtos.java:31451) > > > >> > > > > > > > > > > > > > >> > > > > > > > > org.apache.hadoop.hbase.ipc.RpcServer.call(RpcServer.java:2035) > > > >> > > > > > > > > > > > > > >> > > > > > > > > org.apache.hadoop.hbase.ipc.CallRunner.run(CallRunner.java:107) > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > > >> > > > > > > > > > > > >> > > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > >> > > > > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > org.apache.hadoop.hbase.ipc.RpcExecutor.consumerLoop(RpcExecutor.java:130) > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > >> > > > > > > org.apache.hadoop.hbase.ipc.RpcExecutor$1.run(RpcExecutor.java:107) > > > >> > > > > > > > > > > java.lang.Thread.run(Thread.java:745) > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > There are many similar threads in the thread > dump. > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > I read the source code and I think this is > caused > > by > > > >> > > changes > > > >> > > > of > > > >> > > > > > > > > > > MultiVersionConsistencyControl. > > > >> > > > > > > > > > > A region lock (not a row lock) seems to occur in > > > >> > > > > > > > > > > waitForPreviousTransactionsComplete(). > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > Also we wrote performance test code for > increment > > > >> > operation > > > >> > > > > that > > > >> > > > > > > > > included > > > >> > > > > > > > > > > 100 threads and ran it in local mode. > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > The result is shown below: > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > CDH5.3.1(HBase0.98.6) > > > >> > > > > > > > > > > Throughput(op/s): 12757, Latency(ms): > > > >> 7.975072509210629 > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > CDH5.4.5(HBase1.0.0) > > > >> > > > > > > > > > > Throughput(op/s): 2027, Latency(ms): > > > 49.11840157868772 > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > Thanks, > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > Toshihiro Suzuki > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > > >> > > > > > > > > > > > >> > > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > >> > > > > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > > > > > > >
