Here is a typo, sorry... best regards, hanzhu
On Sun, Dec 19, 2010 at 10:29 AM, Zhu Han <schumi....@gmail.com> wrote: > The problem seems still like the C-heap of JVM, which leaks 70MB every day. > Here is the summary: > > on 12/19: 00000000010c3000 178548K rw--- [ anon ] > on 12/18: 00000000010c3000 110320K rw--- [ anon ] > on 12/17: 00000000010c3000 39256K rw--- [ anon ] > > This should not be the JVM object heap, because the object heap size is > fixed up per the below JVM settings. Here is the map of JVM object heap, > which remains constant. > > 00000000010c3000 39256K rw--- [ anon ] > It should be : 00002b58433c0000 1069824K rw--- [ anon ] > > I'll paste it to open-jdk mailist to seek for help. > > Zhu, >> Couple of quick questions: >> How many threads are in your JVM? >> > > There are hundreds of threads. Here is the settings of Cassandra: > 1) *<ConcurrentReads>8</ConcurrentReads> > <ConcurrentWrites>128</ConcurrentWrites>* > > The thread stack size on this server is 1MB. So I observe hundreds of > single mmap segment as 1MB. > > Can you also post the full commandline as well? >> > Sure. All of them are default settings. > > /usr/bin/java -ea -Xms1G -Xmx1G -XX:+UseParNewGC -XX:+UseConcMarkSweepGC > -XX:+CMSParallelRemarkEnabled -XX:SurvivorRatio=8 -XX:MaxTenuringThreshold=1 > -XX:CMSInitiatingOccupancyFraction=75 -XX:+UseCMSInitiatingOccupancyOnly > -XX:+HeapDumpOnOutOfMemoryError -Dcom.sun.management.jmxremote.port=8080 > -Dcom.sun.management.jmxremote.ssl=false > -Dcom.sun.management.jmxremote.authenticate=false > -Dstorage-config=bin/../conf -cp > bin/../conf:bin/../build/classes:bin/../lib/antlr-3.1.3.jar:bin/../lib/apache-cassandra-0.6.8.jar:bin/../lib/clhm-production.jar:bin/../lib/commons-cli-1.1.jar:bin/../lib/commons-codec-1.2.jar:bin/../lib/commons-collections-3.2.1.jar:bin/../lib/commons-lang-2.4.jar:bin/../lib/google-collections-1.0.jar:bin/../lib/hadoop-core-0.20.1.jar:bin/../lib/high-scale-lib.jar:bin/../lib/ivy-2.1.0.jar:bin/../lib/jackson-core-asl-1.4.0.jar:bin/../lib/jackson-mapper-asl-1.4.0.jar:bin/../lib/jline-0.9.94.jar:bin/../lib/jna.jar:bin/../lib/json-simple-1.1.jar:bin/../lib/libthrift-r917130.jar:bin/../lib/log4j-1.2.14.jar:bin/../lib/slf4j-api-1.5.8.jar:bin/../lib/slf4j-log4j12-1.5.8.jar > org.apache.cassandra.thrift.CassandraDaemon > > >> Also, output of cat /proc/meminfo >> > > This is an openvz based testing environment. So /proc/meminfo is not very > helpful. Whatever, I paste it here. > > > MemTotal: 9838380 kB > MemFree: 4005900 kB > Buffers: 0 kB > Cached: 0 kB > SwapCached: 0 kB > Active: 0 kB > Inactive: 0 kB > HighTotal: 0 kB > HighFree: 0 kB > LowTotal: 9838380 kB > LowFree: 4005900 kB > SwapTotal: 0 kB > SwapFree: 0 kB > Dirty: 0 kB > Writeback: 0 kB > AnonPages: 0 kB > Mapped: 0 kB > Slab: 0 kB > PageTables: 0 kB > NFS_Unstable: 0 kB > Bounce: 0 kB > CommitLimit: 0 kB > Committed_AS: 0 kB > VmallocTotal: 0 kB > VmallocUsed: 0 kB > VmallocChunk: 0 kB > HugePages_Total: 0 > HugePages_Free: 0 > HugePages_Rsvd: 0 > Hugepagesize: 2048 kB > > >> thanks, >> Sri >> >> On Fri, Dec 17, 2010 at 7:15 PM, 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 >> > >> >>>> >> > >> >>> >> > >> >>> >> > >> >> >> > >> >> > >> >> > > >> > >> > >
