Still slow increments though? On Mon, Nov 30, 2015 at 5:05 PM, Bryan Beaudreault <bbeaudrea...@hubspot.com > wrote:
> Those log lines have settled down, they may have been related to a > cluster-wide forced restart at the time. > > On Mon, Nov 30, 2015 at 7:59 PM Bryan Beaudreault < > bbeaudrea...@hubspot.com> > wrote: > > > We've been doing more debugging of this and have set up the read vs write > > handlers to try to at least segment this away so reads can work. We have > > pretty beefy servers, and are running wiht the following settings: > > > > hbase.regionserver.handler.count=1000 > > hbase.ipc.server.read.threadpool.size=50 > > hbase.ipc.server.callqueue.handler.factor=0.025 > > hbase.ipc.server.callqueue.read.ratio=0.6 > > hbase.ipc.server.callqueue.scan.ratio=0.5 > > > > We are seeing all 400 write handlers taken up by row locks for the most > > part. The read handlers are mostly idle. We're thinking of changing the > > ratio here, but are not sure it will help if they are all blocked on a > row > > lock. We just enabled DEBUG logging on all our servers and notice the > > following: > > > > 2015-12-01 00:56:09,015 DEBUG > > org.apache.hadoop.hbase.regionserver.ServerNonceManager: Conflict > detected > > by nonce: [-687451119961178644:7664336281906118656], [state 0, hasWait > > false, activity 00:54:36.240] > > 2015-12-01 00:56:09,015 DEBUG > > org.apache.hadoop.hbase.regionserver.ServerNonceManager: Conflict > detected > > by nonce: [-687451119961178644:-7119840249342174227], [state 0, hasWait > > false, activity 00:54:36.256] > > 2015-12-01 00:56:09,268 DEBUG > > org.apache.hadoop.hbase.regionserver.ServerNonceManager: Conflict > detected > > by nonce: [-5946137511131403479:2112661701888365489], [state 0, hasWait > > false, activity 00:55:01.259] > > 2015-12-01 00:56:09,279 DEBUG > > org.apache.hadoop.hbase.regionserver.ServerNonceManager: Conflict > detected > > by nonce: [4165332617675853029:6256955295384472057], [state 0, hasWait > > false, activity 00:53:58.151] > > 2015-12-01 00:56:09,279 DEBUG > > org.apache.hadoop.hbase.regionserver.ServerNonceManager: Conflict > detected > > by nonce: [4165332617675853029:4961178013070912522], [state 0, hasWait > > false, activity 00:53:58.162] > > > > > > On Mon, Nov 30, 2015 at 6:11 PM Bryan Beaudreault < > > bbeaudrea...@hubspot.com> wrote: > > > >> Sorry the second link should be > >> > https://gist.github.com/bbeaudreault/2994a748da83d9f75085#file-gistfile1-txt-L579 > >> > >> On Mon, Nov 30, 2015 at 6:10 PM Bryan Beaudreault < > >> bbeaudrea...@hubspot.com> wrote: > >> > >>> https://gist.github.com/bbeaudreault/2994a748da83d9f75085 > >>> > >>> An active handler: > >>> > https://gist.github.com/bbeaudreault/2994a748da83d9f75085#file-gistfile1-txt-L286 > >>> One that is locked: > >>> > https://git.hubteam.com/gist/jwilliams/80f37999bfdf55119588#file-gistfile1-txt-L579 > >>> > >>> The difference between pre-rollback and post is that previously we were > >>> seeing things blocked in mvcc. Now we are seeing them blocked on the > >>> upsert. > >>> > >>> It always follows the same pattern, of 1 active handler in the upsert > >>> and the rest blocked waiting for it. > >>> > >>> On Mon, Nov 30, 2015 at 6:05 PM Stack <st...@duboce.net> wrote: > >>> > >>>> 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 > >>>> > > > >> > > > > > > > > > > > >>>> > > > >> > > > > > > > > > > >>>> > > > >> > > > > > > > > > >>>> > > > >> > > > > > > > > >>>> > > > >> > > > > > > > >>>> > > > >> > > > > > > >>>> > > > >> > > > > > >>>> > > > >> > > > > >>>> > > > >> > > > >>>> > > > >> > > >>>> > > > >> > >>>> > > > > > >>>> > > > > >>>> > > > >>>> > > >>>> > >>> >
