I have a pre-production cluster with few data and similar problem... PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND 12916 0.0 80.0 5972756 3231120 ? Sl Oct18 15:49 /usr/bin/java -ea -Xms1G -Xmx1G -XX:+UseParNewGC ...
Data dir: 2.2M data/ Att, Daniel Korndorfer Telecom South America S/A +55 (11) 4302-0188 On Sat, Dec 18, 2010 at 1:15 AM, Zhu Han <schumi....@gmail.com> wrote: > Seems like the problem there after I upgrade to "OpenJDK Runtime > Environment (IcedTea6 1.9.2)". So it is not related to the bug I reported > two days ago. > > Can somebody else share some info with us? What's the java environment you > used? Is it stable for long-lived cassandra instances? > > best regards, > hanzhu > > > On Thu, Dec 16, 2010 at 9:28 PM, Zhu Han <schumi....@gmail.com> wrote: > >> I've tried it. But it does not work for me this afternoon. >> >> Thank you! >> >> best regards, >> hanzhu >> >> >> >> On Thu, Dec 16, 2010 at 8:59 PM, Matthew Conway <m...@backupify.com>wrote: >> >>> Thanks for debugging this, I'm running into the same problem. >>> BTW, if you can ssh into your nodes, you can use jconsole over ssh: >>> http://simplygenius.com/2010/08/jconsole-via-socks-ssh-tunnel.html >>> >>> Matt >>> >>> >>> >>> On Dec 16, 2010, at Thu Dec 16, 2:39 AM, Zhu Han wrote: >>> >>> > Sorry for spam again. :-) >>> > >>> > I think I find the root cause. Here is a bug report[1] on memory leak >>> of >>> > ParNewGC. It is solved by OpenJDK 1.6.0_20(IcedTea6 1.9.2)[2]. >>> > >>> > So the suggestion is: for who runs cassandra of Ubuntu 10.04, please >>> > upgrade OpenJDK to the latest version. >>> > >>> > [1] http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6824570 >>> > [2] >>> http://blog.fuseyism.com/index.php/2010/09/10/icedtea6-19-released/ >>> > >>> > best regards, >>> > hanzhu >>> > >>> > >>> > On Thu, Dec 16, 2010 at 3:10 PM, Zhu Han <schumi....@gmail.com> wrote: >>> > >>> >> The test node is behind a firewall. So I took some time to find a way >>> to >>> >> get JMX diagnostic information from it. >>> >> >>> >> What's interesting is, both the HeapMemoryUsage and NonHeapMemoryUsage >>> >> reported by JVM is quite reasonable. So, it's a myth why the JVM >>> process >>> >> maps such a big anonymous memory region... >>> >> >>> >> $ java -Xmx128m -jar /tmp/cmdline-jmxclient-0.10.3.jar - >>> localhost:8080 >>> >> java.lang:type=Memory HeapMemoryUsage >>> >> 12/16/2010 15:07:45 +0800 org.archive.jmx.Client HeapMemoryUsage: >>> >> committed: 1065025536 >>> >> init: 1073741824 >>> >> max: 1065025536 >>> >> used: 18295328 >>> >> >>> >> $java -Xmx128m -jar /tmp/cmdline-jmxclient-0.10.3.jar - localhost:8080 >>> >> java.lang:type=Memory NonHeapMemoryUsage >>> >> 12/16/2010 15:01:51 +0800 org.archive.jmx.Client NonHeapMemoryUsage: >>> >> committed: 34308096 >>> >> init: 24313856 >>> >> max: 226492416 >>> >> used: 21475376 >>> >> >>> >> If anybody is interested in it, I can provide more diagnostic >>> information >>> >> before I restart the instance. >>> >> >>> >> best regards, >>> >> hanzhu >>> >> >>> >> >>> >> >>> >> On Thu, Dec 16, 2010 at 1:00 PM, Zhu Han <schumi....@gmail.com> >>> wrote: >>> >> >>> >>> After investigating it deeper, I suspect it's native memory leak of >>> JVM. >>> >>> The large anonymous map on lower address space should be the native >>> heap of >>> >>> JVM, but not java object heap. Has anybody met it before? >>> >>> >>> >>> I'll try to upgrade the JVM tonight. >>> >>> >>> >>> best regards, >>> >>> hanzhu >>> >>> >>> >>> >>> >>> >>> >>> On Thu, Dec 16, 2010 at 10:50 AM, Zhu Han <schumi....@gmail.com> >>> wrote: >>> >>> >>> >>>> Hi, >>> >>>> >>> >>>> I have a test node with apache-cassandra-0.6.8 on ubuntu 10.4. The >>> >>>> hardware environment is an OpenVZ container. JVM settings is >>> >>>> # java -Xmx128m -version >>> >>>> java version "1.6.0_18" >>> >>>> OpenJDK Runtime Environment (IcedTea6 1.8.2) (6b18-1.8.2-4ubuntu2) >>> >>>> OpenJDK 64-Bit Server VM (build 16.0-b13, mixed mode) >>> >>>> >>> >>>> This is the memory settings: >>> >>>> >>> >>>> "/usr/bin/java -ea -Xms1G -Xmx1G ..." >>> >>>> >>> >>>> And the ondisk footprint of sstables is very small: >>> >>>> >>> >>>> "#du -sh data/ >>> >>>> "9.8M data/" >>> >>>> >>> >>>> The node was infrequently accessed in the last three weeks. After >>> that, >>> >>>> I observe the abnormal memory utilization by top: >>> >>>> >>> >>>> PID USER PR NI *VIRT* *RES* SHR S %CPU %MEM TIME+ >>> >>>> COMMAND >>> >>>> >>> >>>> 7836 root 15 0 *3300m* *2.4g* 13m S 0 26.0 2:58.51 >>> >>>> java >>> >>>> >>> >>>> The jvm heap utilization is quite normal: >>> >>>> >>> >>>> #sudo jstat -gc -J"-Xmx128m" 7836 >>> >>>> S0C S1C S0U S1U *EC* *EU* *OC* >>> >>>> *OU* *PC PU* YGC YGCT FGC FGCT >>> >>>> GCT >>> >>>> 8512.0 8512.0 372.8 0.0 *68160.0* *5225.7* *963392.0 >>> 508200.7 >>> >>>> 30604.0 18373.4* 480 3.979 2 0.005 3.984 >>> >>>> >>> >>>> And then I try "pmap" to see the native memory mapping. *There is >>> two >>> >>>> large anonymous mmap regions.* >>> >>>> >>> >>>> 00000000080dc000 1573568K rw--- [ anon ] >>> >>>> 00002b2afc900000 1079180K rw--- [ anon ] >>> >>>> >>> >>>> The second one should be JVM heap. What is the first one? Mmap of >>> >>>> sstable should never be anonymous mmap, but file based mmap. *Is it >>> a >>> >>>> native memory leak? *Does cassandra allocate any DirectByteBuffer? >>> >>>> >>> >>>> best regards, >>> >>>> hanzhu >>> >>>> >>> >>> >>> >>> >>> >> >>> >>> >> >
