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 > >>>> > >>> > >>> > >> > >
