> This will work, but I don't think that this is a good way to go, since you > will be treating the symptom and not the actual problem, which is an overloaded node.
I should have been a bit more specific. One would do this for the HDFS and HBase daemons, and not for other subsystems like MR Child processes or the TaskTracker if the oom_adj is inherited by its children. It doesn't cure the problem as you say but will help people avoid shooting their toes off with common misconfiguration issues -- too many mappers, or some other non-Hadoop process on the box chewing up VM. The Ruby interpreter (running Puppet) comes to mind as an example, though recent releases have fixed that particular problem. Best regards, - Andy Problems worthy of attack prove their worth by hitting back. - Piet Hein (via Tom White) >________________________________ > From: Igal Shilman <[email protected]> >To: [email protected]; Andrew Purtell <[email protected]> >Sent: Tuesday, May 1, 2012 9:28 AM >Subject: Re: RegionServer silently stops (only "issue": CMS-concurrent-mark >~80sec) > > >This will work, but I don't think that this is a good way to go, since you >will be treating the symptom and not the actual problem, which is an overloaded node. > >Igal. > > >On Tue, May 1, 2012 at 6:57 PM, Andrew Purtell <[email protected]> wrote: > >Does it make sense to include the below in ./bin/hbase and ./bin/hadoop: >> >> echo -17 > /proc/$PID/oom_adj >> >>-17 is OOM_DISABLE: http://linux-mm.org/OOM_Killer >> >>Best regards, >> >> - Andy >> >>Problems worthy of attack prove their worth by hitting back. - Piet Hein (via >>Tom White) >> >> >> >> >>----- Original Message ----- >>> From: Alex Baranau <[email protected]> >>> To: [email protected] >>> Cc: >>> Sent: Tuesday, May 1, 2012 8:27 AM >>> Subject: Re: RegionServer silently stops (only "issue": CMS-concurrent-mark >>> ~80sec) >>> >>> Yep, that is what I thought (OOM). Our monitoring tool (sematext.com/spm) >>> says that everything was OK with theregard to JVM memory consumption at the >>> time process stopped. But found that oom killer is one who killed it (on >>> this cluster we have HBASE_HEAPSIZE=4000): >>> >>> /var/log/kern.log.1:Apr 30 18:59:04 ip-10-88-231-73 kernel: >>> [32076201.925847] Out of memory: Kill process 15227 (java) score 573 or >>> sacrifice child >>> /var/log/kern.log.1-Apr 30 18:59:04 ip-10-88-231-73 kernel: >>> [32076201.925881] Killed process 15227 (java) total-vm:4716576kB, >>> anon-rss:4364780kB, file-rss:12020kB >>> >>> All clear, thanx! >>> >>> Alex Baranau >>> ------ >>> Sematext :: http://blog.sematext.com/ >>> >>> On Tue, May 1, 2012 at 9:02 AM, Dhaval Shah >>> <[email protected]>wrote: >>> >>>> >>>> >>>> Not sure if its related (or even helpful) but we were using cdh3b4 (which >>>> is 0.90.1) and we saw similar issues with region servers going down.. we >>>> didn't look at GC logs but we had very high zookeeper leases so its >>>> unlikely that the GC could have caused the issue.. this problem went away >>>> when we upgraded to cdh3u3 which is rock steady in terms of region >>>> servers.. (havent had a single region server crash in a month where on the >>>> older version I used to have 1 crash every couple of days).. the only >>>>other >>>> difference between the two is that we use snappy on the newer one and gz >>>>on >>>> the old >>>> >>>> We also noticed that having replication enabled also contributed to the >>>> issues.. >>>> >>>> >>>> ------------------------------ >>>> On Tue 1 May, 2012 3:15 PM IST N Keywal wrote: >>>> >>>> >Hi Alex, >>>> > >>>> >On the same idea, note that hbase is launched with >>>> >-XX:OnOutOfMemoryError="kill -9 %p". >>>> > >>>> >N. >>>> > >>>> >On Tue, May 1, 2012 at 10:41 AM, Igal Shilman <[email protected]> >>> wrote: >>>> > >>>> >> Hi Alex, just to rule out, oom killer, >>>> >> Try this: >>>> >> >>>> >> >>>> >>> http://stackoverflow.com/questions/624857/finding-which-process-was-killed-by-linux-oom-killer >>>> >> >>>> >> >>>> >> On Mon, Apr 30, 2012 at 10:48 PM, Alex Baranau < >>>> [email protected] >>>> >> >wrote: >>>> >> >>>> >> > Hello, >>>> >> > >>>> >> > During recent weeks I constantly see some RSs *silently* >>> dying on our >>>> >> HBase >>>> >> > cluster. By "silently" I mean that process stops, >>> but no errors in >>>> logs >>>> >> > [1]. >>>> >> > >>>> >> > The only thing I can relate to it is long >>> CMS-concurrent-mark: almost >>>> 80 >>>> >> > seconds. But this should not cause issues as it is not a >>>> "stop-the-world" >>>> >> > process. >>>> >> > >>>> >> > Any advice? >>>> >> > >>>> >> > HBase: hbase-0.90.4-cdh3u3 >>>> >> > Hadoop: 0.20.2-cdh3u3 >>>> >> > >>>> >> > Thank you, >>>> >> > Alex Baranau >>>> >> > >>>> >> > [1] >>>> >> > >>>> >> > last lines from RS log (no errors before too, and nothing >>> written in >>>> >> *.out >>>> >> > file): >>>> >> > >>>> >> > 2012-04-30 18:52:11,806 DEBUG >>>> >> > org.apache.hadoop.hbase.regionserver.CompactSplitThread: >>> Compaction >>>> >> > requested for agg-sa-1.3,0011| >>>> >> > >>>> >> > >>>> >> >>>> >>> te|dtc|\x00\x00\x00\x00\x00\x00<\x1E\x002\x00\x00\x00\x015\x9C_n\x00\x00\x00\x00\x00\x00\x00\x00\x00,1334852280902.4285f9339b520ee617c087c0fd0dbf65. >>>> >> > because regionserver60020.cacheFlusher; priority=-1, >>> compaction queue >>>> >> > size=0 >>>> >> > 2012-04-30 18:54:58,779 DEBUG >>>> >> > >>> org.apache.hadoop.hbase.regionserver.wal.SequenceFileLogWriter: using >>>> new >>>> >> > createWriter -- HADOOP-6840 >>>> >> > 2012-04-30 18:54:58,779 DEBUG >>>> >> > >>> org.apache.hadoop.hbase.regionserver.wal.SequenceFileLogWriter: >>>> >> > >>>> >> > >>>> >> >>>> >>> Path=hdfs://xxx.ec2.internal/hbase/.logs/xxx.ec2.internal,60020,1335706613397/xxx.ec2.internal%3A60020.1335812098651, >>>> >> > syncFs=true, hflush=false >>>> >> > 2012-04-30 18:54:58,874 INFO >>>> >> org.apache.hadoop.hbase.regionserver.wal.HLog: >>>> >> > Roll >>>> >> > >>>> >> > >>>> >> >>>> >>> /hbase/.logs/xxx.ec2.internal,60020,1335706613397/xxx.ec2.internal%3A60020.1335811856672, >>>> >> > entries=73789, filesize=63773934. New hlog >>>> >> > >>>> >> > >>>> >> >>>> >>> /hbase/.logs/xxx.ec2.internal,60020,1335706613397/xxx.ec2.internal%3A60020.1335812098651 >>>> >> > 2012-04-30 18:56:31,867 INFO >>>> >> > org.apache.hadoop.hbase.regionserver.MemStoreFlusher: Flush >>> thread >>>> woke >>>> >> up >>>> >> > with memory above low water. >>>> >> > 2012-04-30 18:56:31,867 INFO >>>> >> > org.apache.hadoop.hbase.regionserver.MemStoreFlusher: Flush >>> of region >>>> >> > agg-sa-1.3,s_00I4| >>>> >> > >>>> >> > >>>> >> >>>> >>> tdqc\x00docs|mrtdocs|\x00\x00\x00\x00\x00\x03\x11\xF4\x00none\x00|1334692562\x00\x0D\xE0\xB6\xB3\xA7c\xFF\xBC|26837373\x00\x00\x00\x016\xC1\xE0D\xBE\x00\x00\x00\x00\x00\x00\x00\x00,1335761291026.30b127193485342359eadf1586819805. >>>> >> > due to global heap pressure >>>> >> > 2012-04-30 18:56:31,867 DEBUG >>>> >> org.apache.hadoop.hbase.regionserver.HRegion: >>>> >> > Started memstore flush for agg-sa-1.3,s_00I4| >>>> >> > >>>> >> > >>>> >> >>>> >>> tdqc\x00docs|mrtdocs|\x00\x00\x00\x00\x00\x03\x11\xF4\x00none\x00|1334692562\x00\x0D\xE0\xB6\xB3\xA7c\xFF\xBC|26837373\x00\x00\x00\x016\xC1\xE0D\xBE\x00\x00\x00\x00\x00\x00\x00\x00,1335761291026.30b127193485342359eadf1586819805., >>>> >> > current region memstore size 138.1m >>>> >> > 2012-04-30 18:56:31,867 DEBUG >>>> >> org.apache.hadoop.hbase.regionserver.HRegion: >>>> >> > Finished snapshotting, commencing flushing stores >>>> >> > 2012-04-30 18:56:56,303 DEBUG >>>> >> > org.apache.hadoop.hbase.io.hfile.LruBlockCache: LRU Stats: >>>> total=322.84 >>>> >> MB, >>>> >> > free=476.34 MB, max=799.17 MB, blocks=5024, >>> accesses=12189396, >>>> >> hits=127592, >>>> >> > hitRatio=1.04%%, cachingAccesses=132480, cachingHits=126949, >>>> >> > cachingHitsRatio=95.82%%, evictions=0, evicted=0, >>> evictedPerRun=NaN >>>> >> > 2012-04-30 18:56:59,026 INFO >>>> org.apache.hadoop.hbase.regionserver.Store: >>>> >> > Renaming flushed file at >>>> >> > >>>> >> > >>>> >> >>>> >>> hdfs://zzz.ec2.internal/hbase/agg-sa-1.3/30b127193485342359eadf1586819805/.tmp/391890051647401997 >>>> >> > to >>>> >> > >>>> >> > >>>> >> >>>> >>> hdfs://zzz.ec2.internal/hbase/agg-sa-1.3/30b127193485342359eadf1586819805/a/1139737908876846168 >>>> >> > 2012-04-30 18:56:59,034 INFO >>>> org.apache.hadoop.hbase.regionserver.Store: >>>> >> > Added >>>> >> > >>>> >> > >>>> >> >>>> >>> hdfs://zzz.ec2.internal/hbase/agg-sa-1.3/30b127193485342359eadf1586819805/a/1139737908876846168, >>>> >> > entries=476418, sequenceid=880198761, memsize=138.1m, >>> filesize=5.7m >>>> >> > 2012-04-30 18:56:59,097 INFO >>>> >> org.apache.hadoop.hbase.regionserver.HRegion: >>>> >> > Finished memstore flush of ~138.1m for region >>> agg-sa-1.3,s_00I4| >>>> >> > >>>> >> > >>>> >> >>>> >>> tdqc\x00docs|mrtdocs|\x00\x00\x00\x00\x00\x03\x11\xF4\x00none\x00|1334692562\x00\x0D\xE0\xB6\xB3\xA7c\xFF\xBC|26837373\x00\x00\x00\x016\xC1\xE0D\xBE\x00\x00\x00\x00\x00\x00\x00\x00,1335761291026.30b127193485342359eadf1586819805. >>>> >> > in 27230ms, sequenceid=880198761, compaction requested=false >>>> >> > ~ >>>> >> > >>>> >> > [2] >>>> >> > >>>> >> > last lines from GC log: >>>> >> > >>>> >> > 2012-04-30T18:58:46.683+0000: 105717.791: [GC 105717.791: >>> [ParNew: >>>> >> > 35638K->1118K(38336K), 0.0548970 secs] >>> 3145651K->3111412K(4091776K) >>>> >> > icms_dc=6 , 0.0550360 secs] [Times: user=0.08 sys=0.00, >>> real=0.09 >>>> secs] >>>> >> > 2012-04-30T18:58:46.961+0000: 105718.069: [GC 105718.069: >>> [ParNew: >>>> >> > 35230K->2224K(38336K), 0.0802440 secs] >>> 3145524K->3112533K(4091776K) >>>> >> > icms_dc=6 , 0.0803810 secs] [Times: user=0.06 sys=0.00, >>> real=0.13 >>>> secs] >>>> >> > 2012-04-30T18:58:47.114+0000: 105718.222: >>> [CMS-concurrent-mark: >>>> >> > 8.770/80.230 secs] [Times: user=61.34 sys=5.69, real=80.23 >>> secs] >>>> >> > 2012-04-30T18:58:47.114+0000: 105718.222: >>>> [CMS-concurrent-preclean-start] >>>> >> > 2012-04-30T18:58:47.183+0000: 105718.291: [GC 105718.291: >>> [ParNew: >>>> >> > 36336K->3895K(38336K), 0.0272610 secs] >>> 3146645K->3114281K(4091776K) >>>> >> > icms_dc=6 , 0.0274040 secs] [Times: user=0.05 sys=0.00, >>> real=0.03 >>>> secs] >>>> >> > 2012-04-30T18:58:47.452+0000: 105718.560: [GC 105718.560: >>> [ParNew: >>>> >> > 37990K->3082K(38336K), 0.0504660 secs] >>> 3148376K->3114329K(4091776K) >>>> >> > icms_dc=6 , 0.0506020 secs] [Times: user=0.06 sys=0.00, >>> real=0.05 >>>> secs] >>>> >> > 2012-04-30T18:58:47.823+0000: 105718.930: [GC 105718.931: >>> [ParNew: >>>> >> > 37194K->3340K(38336K), 0.0419660 secs] >>> 3148441K->3115727K(4091776K) >>>> >> > icms_dc=6 , 0.0421110 secs] [Times: user=0.05 sys=0.00, >>> real=0.04 >>>> secs] >>>> >> > 2012-04-30T18:58:48.099+0000: 105719.207: [GC 105719.207: >>> [ParNew: >>>> >> > 37351K->3249K(38336K), 0.0695950 secs] >>> 3149738K->3115636K(4091776K) >>>> >> > icms_dc=6 , 0.0697320 secs] [Times: user=0.07 sys=0.00, >>> real=0.07 >>>> secs] >>>> >> > 2012-04-30T18:58:48.447+0000: 105719.555: [GC 105719.555: >>> [ParNew: >>>> >> > 37361K->2512K(38336K), 0.0510560 secs] >>> 3149748K->3116166K(4091776K) >>>> >> > icms_dc=6 , 0.0512050 secs] [Times: user=0.05 sys=0.00, >>> real=0.00 >>>> secs] >>>> >> > 2012-04-30T18:58:48.794+0000: 105719.902: [GC 105719.902: >>> [ParNew: >>>> >> > 36624K->2616K(38336K), 0.1986770 secs] >>> 3150278K->3116270K(4091776K) >>>> >> > icms_dc=6 , 0.1988160 secs] [Times: user=0.05 sys=0.00, >>> real=0.20 >>>> secs] >>>> >> > 2012-04-30T18:58:49.614+0000: 105720.722: [GC 105720.722: >>> [ParNew: >>>> >> > 36728K->3450K(38336K), 0.1099190 secs] >>> 3150382K->3117103K(4091776K) >>>> >> > icms_dc=6 , 0.1100650 secs] [Times: user=0.05 sys=0.00, >>> real=0.11 >>>> secs] >>>> >> > 2012-04-30T18:58:50.631+0000: 105721.739: [GC 105721.739: >>> [ParNew: >>>> >> > 37546K->3176K(38336K), 0.2096280 secs] >>> 3151199K->3117154K(4091776K) >>>> >> > icms_dc=6 , 0.2097770 secs] [Times: user=0.10 sys=0.00, >>> real=0.21 >>>> secs] >>>> >> > 2012-04-30T18:58:51.300+0000: 105722.408: [GC 105722.408: >>> [ParNew: >>>> >> > 37288K->3928K(38336K), 0.0873820 secs] >>> 3151266K->3117907K(4091776K) >>>> >> > icms_dc=6 , 0.0875310 secs] [Times: user=0.05 sys=0.00, >>> real=0.08 >>>> secs] >>>> >> > 2012-04-30T18:58:52.109+0000: 105723.217: [GC 105723.217: >>> [ParNew: >>>> >> > 38040K->2095K(38336K), 0.0791560 secs] >>> 3152019K->3116839K(4091776K) >>>> >> > icms_dc=6 , 0.0792970 secs] [Times: user=0.05 sys=0.00, >>> real=0.08 >>>> secs] >>>> >> > 2012-04-30T18:58:53.132+0000: 105724.240: [GC 105724.240: >>> [ParNew: >>>> >> > 36207K->2581K(38336K), 0.1651210 secs] >>> 3150951K->3117700K(4091776K) >>>> >> > icms_dc=6 , 0.1652650 secs] [Times: user=0.06 sys=0.00, >>> real=0.16 >>>> secs] >>>> >> > 2012-04-30T18:58:55.402+0000: 105726.510: [GC 105726.510: >>> [ParNew: >>>> >> > 36693K->2297K(38336K), 0.1262480 secs] >>> 3151812K->3117742K(4091776K) >>>> >> > icms_dc=6 , 0.1264420 secs] [Times: user=0.06 sys=0.00, >>> real=0.13 >>>> secs] >>>> >> > 2012-04-30T18:58:56.103+0000: 105727.211: [GC 105727.211: >>> [ParNew: >>>> >> > 36409K->4224K(38336K), 0.3658760 secs] >>> 3151854K->3120205K(4091776K) >>>> >> > icms_dc=6 , 0.3660220 secs] >>>> >> > >>>> >> >>>> >>>> >>> >> > > >
