The default periodic flush is 1 hour. If you have a lot of regions and your write distribution is not strictly uniform this can cause a lot of small flushes, as you are seeing. I tuned this up to 12 hours in my cluster, and may tune it up further. It made a big impact on the number of minor compactions running throughout the day.
On Thu, Nov 6, 2014 at 2:14 PM, Pere Kyle <p...@whisper.sh> wrote: > Thanks again for your help! > > I do not see a single entry in my logs for memstore pressure/global heap. > I do see tons of logs from the periodicFlusher: > http://pastebin.com/8ZyVz8AH > > This seems odd to me. Today alone there are 1829 flushes from > periodicFlusher. Is there some other log4j property I need to set? > > Here are some logs from memstore flushes: > 2014-11-06 19:11:42,000 INFO > org.apache.hadoop.hbase.regionserver.StoreFile > (regionserver60020.cacheFlusher): NO General Bloom and NO DeleteFamily was > added to HFile (hdfs:// > 10.227.42.38:9000/hbase/weaver_events/4bafc4f16d984b2cca905e149584df8e/.tmp/c42aacd7e6c047229bb12291510bff50 > ) > 2014-11-06 19:11:42,000 INFO org.apache.hadoop.hbase.regionserver.Store > (regionserver60020.cacheFlusher): Flushed , sequenceid=67387584, > memsize=29.5 K, into tmp file hdfs:// > 10.227.42.38:9000/hbase/weaver_events/4bafc4f16d984b2cca905e149584df8e/.tmp/c42aacd7e6c047229bb12291510bff50 > 2014-11-06 19:11:44,683 INFO org.apache.hadoop.hbase.regionserver.Store > (regionserver60020.cacheFlusher): Added hdfs:// > 10.227.42.38:9000/hbase/weaver_events/4bafc4f16d984b2cca905e149584df8e/d/c42aacd7e6c047229bb12291510bff50, > entries=150, sequenceid=67387584, filesize=3.2 K > 2014-11-06 19:11:44,685 INFO org.apache.hadoop.hbase.regionserver.HRegion > (regionserver60020.cacheFlusher): Finished memstore flush of ~29.5 K/30176, > currentsize=0/0 for region > weaver_events,21476b2c-7257-4787-9309-aaeab1e85392,1415157492044.4bafc4f16d984b2cca905e149584df8e. > in 3880ms, sequenceid=67387584, compaction requested=false > 2014-11-06 19:11:44,714 INFO > org.apache.hadoop.hbase.regionserver.StoreFile > (regionserver60020.cacheFlusher): Delete Family Bloom filter type for > hdfs:// > 10.227.42.38:9000/hbase/weaver_events/9b4c4b73035749a9865103366c9a5a87/.tmp/f10e53628784487290f788802808777a: > CompoundBloomFilterWriter > 2014-11-06 19:11:44,729 INFO > org.apache.hadoop.hbase.regionserver.StoreFile > (regionserver60020.cacheFlusher): NO General Bloom and NO DeleteFamily was > added to HFile (hdfs:// > 10.227.42.38:9000/hbase/weaver_events/9b4c4b73035749a9865103366c9a5a87/.tmp/f10e53628784487290f788802808777a > ) > 2014-11-06 19:11:44,729 INFO org.apache.hadoop.hbase.regionserver.Store > (regionserver60020.cacheFlusher): Flushed , sequenceid=67387656, > memsize=41.2 K, into tmp file hdfs:// > 10.227.42.38:9000/hbase/weaver_events/9b4c4b73035749a9865103366c9a5a87/.tmp/f10e53628784487290f788802808777a > 2014-11-06 19:11:44,806 INFO org.apache.hadoop.hbase.regionserver.Store > (regionserver60020.cacheFlusher): Added hdfs:// > 10.227.42.38:9000/hbase/weaver_events/9b4c4b73035749a9865103366c9a5a87/d/f10e53628784487290f788802808777a, > entries=210, sequenceid=67387656, filesize=4.1 K > 2014-11-06 19:11:44,807 INFO org.apache.hadoop.hbase.regionserver.HRegion > (regionserver60020.cacheFlusher): Finished memstore flush of ~41.2 K/42232, > currentsize=17.7 K/18080 for region > weaver_events,30f6c923-8a37-4324-a404-377decd3ae06,1415154978597.9b4c4b73035749a9865103366c9a5a87. > in 99ms, sequenceid=67387656, compaction requested=false > > Thanks! > -Pere > On Nov 6, 2014, at 10:27 AM, Ted Yu <yuzhih...@gmail.com> wrote: > > > bq. Do I need to restart master for the memstore to take effect? > > No. memstore is used by region server. > > > > Looks like debug logging was not turned on (judging from your previous > > pastebin). > > Some of flush related logs are at INFO level. e.g. Do you see any of the > > following log ? > > > > LOG.info("Flush of region " + regionToFlush + " due to global heap > > pressure"); > > > > Take a look > > at > ./src/main/java/org/apache/hadoop/hbase/regionserver/MemStoreFlusher.java > > and you will find all the logs. > > > > Cheers > > > > On Thu, Nov 6, 2014 at 10:05 AM, Pere Kyle <p...@whisper.sh> wrote: > > > >> So I have set the heap to 12Gb and the memstore limit to upperLimit .5 > >> lowerLimit .45. I am not seeing any changes in behavior from the > cluster so > >> far, i have restarted 4/17 region servers. Do I need to restart master > for > >> the memstore to take effect? Also how do I enable logging to show why a > >> region is being flushed? I don’t ever seen the region flushes in my > logs. > >> > >> Thanks, > >> Pere > >> On Nov 6, 2014, at 7:12 AM, Ted Yu <yuzhih...@gmail.com> wrote: > >> > >>> bq. to increase heap and increase the memstore limit? > >>> > >>> Yes. That would be an action that bears fruit. > >>> Long term, you should merge the small regions. > >>> > >>> Cheers > >>> > >>> On Wed, Nov 5, 2014 at 11:20 PM, Pere Kyle <p...@whisper.sh> wrote: > >>> > >>>> Watching closely a region server in action. It seems that the > memstores > >>>> are being flushed at around 2MB on the regions. This would seem to > >>>> indicate that there is not enough heap for the memstore and I am > hitting > >>>> the upper bound of limit (default). Would this be a fair assumption? > >> Should > >>>> I look to increase heap and increase the memstore limit? > >>>> > >>>> Thanks! > >>>> -Pere > >>>> > >>>> On Nov 5, 2014, at 10:26 PM, Ted Yu <yuzhih...@gmail.com> wrote: > >>>> > >>>>> You can use ConstantSizeRegionSplitPolicy. > >>>>> Split policy can be specified per table. See the following example > >>>>> in create.rb : > >>>>> > >>>>> hbase> create 't1', 'f1', {NUMREGIONS => 15, SPLITALGO => > >>>>> 'HexStringSplit'} > >>>>> > >>>>> In 0.94.18, there isn't online merge. So you have to use other method > >> to > >>>>> merge the small regions. > >>>>> > >>>>> Cheers > >>>>> > >>>>> On Wed, Nov 5, 2014 at 10:14 PM, Pere Kyle <p...@whisper.sh> wrote: > >>>>> > >>>>>> Ted, > >>>>>> > >>>>>> Thanks so much for that information. I now see why this split too > >> often, > >>>>>> but what I am not sure of is how to fix this without blowing away > the > >>>>>> cluster. Add more heap? > >>>>>> > >>>>>> Another symptom I have noticed is that load on the Master instance > >> hbase > >>>>>> daemon has been pretty high (load average 4.0, whereas it used to be > >>>> 1.0) > >>>>>> > >>>>>> Thanks, > >>>>>> Pere > >>>>>> > >>>>>> On Nov 5, 2014, at 9:56 PM, Ted Yu <yuzhih...@gmail.com> wrote: > >>>>>> > >>>>>>> IncreasingToUpperBoundRegionSplitPolicy is the default split > policy. > >>>>>>> > >>>>>>> You can read the javadoc of this class to see how it works. > >>>>>>> > >>>>>>> Cheers > >>>>>>> > >>>>>>> On Wed, Nov 5, 2014 at 9:39 PM, Ted Yu <yuzhih...@gmail.com> > wrote: > >>>>>>> > >>>>>>>> Can you provide a bit more information (such as HBase release) ? > >>>>>>>> > >>>>>>>> If you pastebin one of the region servers' log, that would help us > >>>>>>>> determine the cause. > >>>>>>>> > >>>>>>>> Cheers > >>>>>>>> > >>>>>>>> > >>>>>>>> On Wed, Nov 5, 2014 at 9:29 PM, Pere Kyle <p...@whisper.sh> > wrote: > >>>>>>>> > >>>>>>>>> Hello, > >>>>>>>>> > >>>>>>>>> Recently our cluster which has been running fine for 2 weeks > split > >> to > >>>>>>>>> 1024 regions at 1GB per region, after this split the cluster is > >>>>>> unusable. > >>>>>>>>> Using the performance benchmark I was getting a little better > than > >>>> 100 > >>>>>> w/s, > >>>>>>>>> whereas before it was 5000 w/s. There are 15 nodes of m2.2xlarge > >> with > >>>>>> 8GB > >>>>>>>>> heap reserved for Hbase > >>>>>>>>> > >>>>>>>>> Any Ideas? I am stumped: > >>>>>>>>> > >>>>>>>>> Thanks, > >>>>>>>>> Pere > >>>>>>>>> > >>>>>>>>> Here is the current > >>>>>>>>> hbase-site.xml > >>>>>>>>> <?xml version="1.0"?> > >>>>>>>>> <?xml-stylesheet type="text/xsl" href="configuration.xsl"?> > >>>>>>>>> <configuration> > >>>>>>>>> <property> > >>>>>>>>> <name>hbase.snapshot.enabled</name> > >>>>>>>>> <value>true</value> > >>>>>>>>> </property> > >>>>>>>>> > >>>>>>>>> > >>>>>> > >>>> > >> > <property><name>fs.hdfs.impl</name><value>emr.hbase.fs.BlockableFileSystem</value></property> > >>>>>>>>> > >>>>>>>>> > >>>>>> > >>>> > >> > <property><name>hbase.regionserver.handler.count</name><value>50</value></property> > >>>>>>>>> > >>>>>>>>> > >>>>>> > >>>> > >> > <property><name>hbase.cluster.distributed</name><value>true</value></property> > >>>>>>>>> > >>>>>>>>> > >>>>>> > >>>> > >> > <property><name>hbase.tmp.dir</name><value>/mnt/var/lib/hbase/tmp-data</value></property> > >>>>>>>>> > >>>>>>>>> > >>>>>> > >>>> > >> > <property><name>hbase.master.wait.for.log.splitting</name><value>true</value></property> > >>>>>>>>> > >>>>>>>>> > >>>>>> > >>>> > >> > <property><name>hbase.hregion.memstore.flush.size</name><value>134217728</value></property> > >>>>>>>>> > <property><name>hbase.hregion.max.filesize</name><value>5073741824 > >>>>>>>>> </value></property> > >>>>>>>>> > >>>>>>>>> > >>>>>> > >>>> > >> > <property><name>zookeeper.session.timeout</name><value>60000</value></property> > >>>>>>>>> > >>>>>>>>> > >>>>>> > >>>> > >> > <property><name>hbase.thrift.maxQueuedRequests</name><value>0</value></property> > >>>>>>>>> > >>>>>>>>> > >>>>>> > >>>> > >> > <property><name>hbase.client.scanner.caching</name><value>1000</value></property> > >>>>>>>>> > >>>>>>>>> > >>>>>> > >>>> > >> > <property><name>hbase.hregion.memstore.block.multiplier</name><value>4</value></property> > >>>>>>>>> </configuration> > >>>>>>>>> > >>>>>>>>> hbase-env.sh > >>>>>>>>> # The maximum amount of heap to use, in MB. Default is 1000. > >>>>>>>>> export HBASE_HEAPSIZE=8000 > >>>>>>>>> > >>>>>>>>> # Extra Java runtime options. > >>>>>>>>> # Below are what we set by default. May only work with SUN JVM. > >>>>>>>>> # For more on why as well as other possible settings, > >>>>>>>>> # see http://wiki.apache.org/hadoop/PerformanceTuning > >>>>>>>>> export HBASE_OPTS="-XX:+UseConcMarkSweepGC” > >>>>>>>>> > >>>>>>>>> hbase-env.sh > >>>>>>>> > >>>>>>>> > >>>>>>>> > >>>>>> > >>>>>> > >>>> > >>>> > >> > >> > >
