see http://wiki.apache.org/cassandra/FAQ#mmap
> which cause the OS low memory. If the memory is used for mmapped access the os can get it back later. Is the low free memory causing a problem ? Cheers ----------------- Aaron Morton Freelance Developer @aaronmorton http://www.thelastpickle.com On 12/06/2012, at 5:52 PM, Jason Tang wrote: > Hi > > I found some information of this issue > And seems we can have other strategy for data access to reduce mmap usage, in > order to use less memory. > > But I didn't find the document to describe the parameters for Cassandra 1.x, > is it a good way to use this parameter to reduce shared memory usage and > what's the impact? (btw, our data model is dynamical, which means the > although the through put is high, but the life cycle of the data is short, > one hour or less). > > " > # Choices are auto, standard, mmap, and mmap_index_only. > disk_access_mode: auto > " > > http://comments.gmane.org/gmane.comp.db.cassandra.user/7390 > > 2012/6/12 Jason Tang <ares.t...@gmail.com> > See my post, I limit the HVM heap 6G, but actually Cassandra will use more > memory which is not calculated in JVM heap. > > I use top to monitor total memory used by Cassandra. > > ============================= > -Xms6G -Xmx6G -Xmn1600M > > 2012/6/12 Jeffrey Kesselman <jef...@gmail.com> > Btw. I suggest you spin up JConsole as it will give you much more detai kon > what your VM is actually doing. > > > > On Mon, Jun 11, 2012 at 9:14 PM, Jason Tang <ares.t...@gmail.com> wrote: > Hi > > We have some problem with Cassandra memory usage, we configure the JVM > HEAP 6G, but after runing Cassandra for several hours (insert, update, > delete). The total memory used by Cassandra go up to 15G, which cause the OS > low memory. > > So I wonder if it is normal to have so many memory used by cassandra? > > And how to limit the native memory used by Cassandra? > > > =========================== > Cassandra 1.0.3, 64 bit jdk. > > Memory ocupied by Cassandra 15G > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND > 9567 casadm 20 0 28.3g 15g 9.1g S 269 65.1 385:57.65 java > > ============================= > -Xms6G -Xmx6G -Xmn1600M > > # ps -ef | grep 9567 > casadm 9567 1 55 Jun11 ? 05:59:44 /opt/jdk1.6.0_29/bin/java -ea > -javaagent:/opt/dve/cassandra/bin/../lib/jamm-0.2.5.jar > -XX:+UseThreadPriorities -XX:ThreadPriorityPolicy=42 -Xms6G -Xmx6G -Xmn1600M > -XX:+HeapDumpOnOutOfMemoryError -Xss128k -XX:+UseParNewGC > -XX:+UseConcMarkSweepGC -XX:+CMSParallelRemarkEnabled -XX:SurvivorRatio=8 > -XX:MaxTenuringThreshold=1 -XX:CMSInitiatingOccupancyFraction=75 > -XX:+UseCMSInitiatingOccupancyOnly -Djava.net.preferIPv4Stack=true > -Dcom.sun.management.jmxremote.port=6080 > -Dcom.sun.management.jmxremote.ssl=false > -Dcom.sun.management.jmxremote.authenticate=false > -Daccess.properties=/opt/dve/cassandra/conf/access.properties > -Dpasswd.properties=/opt/dve/cassandra/conf/passwd.properties > -Dpasswd.mode=MD5 -Dlog4j.configuration=log4j-server.properties > -Dlog4j.defaultInitOverride=true -cp > /opt/dve/cassandra/bin/../conf:/opt/dve/cassandra/bin/../build/classes/main:/opt/dve/cassandra/bin/../build/classes/thrift:/opt/dve/cassandra/bin/../lib/Cassandra-Extensions-1.0.0.jar:/opt/dve/cassandra/bin/../lib/antlr-3.2.jar:/opt/dve/cassandra/bin/../lib/apache-cassandra-1.0.3.jar:/opt/dve/cassandra/bin/../lib/apache-cassandra-clientutil-1.0.3.jar:/opt/dve/cassandra/bin/../lib/apache-cassandra-thrift-1.0.3.jar:/opt/dve/cassandra/bin/../lib/avro-1.4.0-fixes.jar:/opt/dve/cassandra/bin/../lib/avro-1.4.0-sources-fixes.jar:/opt/dve/cassandra/bin/../lib/commons-cli-1.1.jar:/opt/dve/cassandra/bin/../lib/commons-codec-1.2.jar:/opt/dve/cassandra/bin/../lib/commons-lang-2.4.jar:/opt/dve/cassandra/bin/../lib/compress-lzf-0.8.4.jar:/opt/dve/cassandra/bin/../lib/concurrentlinkedhashmap-lru-1.2.jar:/opt/dve/cassandra/bin/../lib/guava-r08.jar:/opt/dve/cassandra/bin/../lib/high-scale-lib-1.1.2.jar:/opt/dve/cassandra/bin/../lib/jackson-core-asl-1.4.0.jar:/opt/dve/cassandra/bin/../lib/jackson-mapper-asl-1.4.0.jar:/opt/dve/cassandra/bin/../lib/jamm-0.2.5.jar:/opt/dve/cassandra/bin/../lib/jline-0.9.94.jar:/opt/dve/cassandra/bin/../lib/json-simple-1.1.jar:/opt/dve/cassandra/bin/../lib/libthrift-0.6.jar:/opt/dve/cassandra/bin/../lib/log4j-1.2.16.jar:/opt/dve/cassandra/bin/../lib/servlet-api-2.5-20081211.jar:/opt/dve/cassandra/bin/../lib/slf4j-api-1.6.1.jar:/opt/dve/cassandra/bin/../lib/slf4j-log4j12-1.6.1.jar:/opt/dve/cassandra/bin/../lib/snakeyaml-1.6.jar:/opt/dve/cassandra/bin/../lib/snappy-java-1.0.4.1.jar > org.apache.cassandra.thrift.CassandraDaemon > > ============================== > # nodetool -h 127.0.0.1 -p 6080 info > Token : 85070591730234615865843651857942052864 > Gossip active : true > Load : 20.59 GB > Generation No : 1339423322 > Uptime (seconds) : 39626 > Heap Memory (MB) : 3418.42 / 5984.00 > Data Center : datacenter1 > Rack : rack1 > Exceptions : 0 > > ============================= > All row cache and key cache are disabled by default > > Key cache: disabled > Row cache: disabled > > > ============================== > > # pmap 9567 > 9567: java > START SIZE RSS PSS DIRTY SWAP PERM MAPPING > 0000000040000000 36K 36K 36K 0K 0K r-xp > /opt/jdk1.6.0_29/bin/java > 0000000040108000 8K 8K 8K 8K 0K rwxp > /opt/jdk1.6.0_29/bin/java > 000000004010a000 18040K 17988K 17988K 17988K 0K rwxp [heap] > 000000067ae00000 6326700K 6258664K 6258664K 6258664K 0K rwxp [anon] > 00000007fd06b000 48724K 0K 0K 0K 0K rwxp [anon] > 00007fbed1530000 1331104K 0K 0K 0K 0K r-xs > /var/cassandra/data/drc/queue-hb-219-Data.db > 00007fbf22918000 2097152K 0K 0K 0K 0K r-xs > /var/cassandra/data/drc/queue-hb-219-Data.db > 00007fbfa2918000 2097148K 1124464K 1124462K 0K 0K r-xs > /var/cassandra/data/drc/queue-hb-219-Data.db > 00007fc022917000 2097156K 2096496K 2096492K 0K 0K r-xs > /var/cassandra/data/drc/queue-hb-219-Data.db > 00007fc0a2918000 2097148K 2097148K 2097146K 0K 0K r-xs > /var/cassandra/data/drc/queue-hb-219-Data.db > 00007fc1a2917000 733584K 6444K 6444K 0K 0K r-xs > /var/cassandra/data/drc/queue-hb-109-Data.db > 00007fc1cf57b000 2097148K 20980K 20980K 0K 0K r-xs > /var/cassandra/data/drc/queue-hb-109-Data.db > 00007fc24f57a000 2097152K 456480K 456478K 0K 0K r-xs > /var/cassandra/data/drc/queue-hb-109-Data.db > 00007fc2cf57a000 2097156K 1168320K 1168318K 0K 0K r-xs > /var/cassandra/data/drc/queue-hb-109-Data.db > 00007fc34f57b000 2097148K 1177520K 1177520K 0K 0K r-xs > /var/cassandra/data/drc/queue-hb-109-Data.db > 00007fc405629000 618708K 338248K 338248K 0K 0K r-xs > /var/cassandra/data/drc/queue-hb-230-Data.db > 00007fc42b25e000 620388K 289024K 289024K 0K 0K r-xs > /var/cassandra/data/drc/queue-hb-224-Data.db > 00007fc451037000 619160K 342108K 342108K 0K 0K r-xs > /var/cassandra/data/drc/queue-hb-216-Data.db > 00007fc62b7df000 132696K 0K 0K 0K 0K r-xs > /var/cassandra/data/drc/queue.idxInQueueTime-hb-175-Data.db > 00007fc6de8e0000 132696K 0K 0K 0K 0K r-xs > /var/cassandra/data/drc/queue.idxRecvTime-hb-175-Data.db > 00007fc6f2bcc000 52492K 0K 0K 0K 0K r-xs > /var/cassandra/data/drc/queue.idxPartitionId-hb-211-Data.db > 00007fc6f64dc000 43784K 40840K 40840K 0K 0K r-xs > /var/cassandra/data/drc/fpr_index-hb-91-Data.db > 00007fc707ca6000 68968K 37724K 37724K 0K 0K r-xs > /var/cassandra/data/drc/queue-hb-219-Index.db > 00007fc70c000000 2468K 2436K 2436K 2436K 0K rwxp [anon] > 00007fc70c269000 63068K 0K 0K 0K 0K ---p [anon] > 00007fc710b9e000 52888K 0K 0K 0K 0K r-xs > /var/cassandra/data/drc/queue.idxInQueueTime-hb-216-Data.db > 00007fc713f44000 52952K 0K 0K 0K 0K r-xs > /var/cassandra/data/drc/queue.idxFireTimeRange-hb-140-Data.db > 00007fc7172fa000 52952K 0K 0K 0K 0K r-xs > /var/cassandra/data/drc/queue.idxFireTime-hb-140-Data.db > 00007fc71bd13000 162992K 162984K 162984K 0K 0K r-xs > /var/cassandra/data/drc/fpr_index-hb-80-Data.db > 00007fc725c3f000 52952K 28712K 28712K 0K 0K r-xs > /var/cassandra/data/drc/queue.idxInQueueTimeRange-hb-140-Data.db > 00007fc728ff5000 52952K 0K 0K 0K 0K r-xs > /var/cassandra/data/drc/queue.idxRecvTimeRange-hb-140-Data.db > 00007fc72d026000 52480K 0K 0K 0K 0K r-xs > /var/cassandra/data/drc/queue.idxRecvTimeRange-hb-211-Data.db > 00007fc730366000 52564K 0K 0K 0K 0K r-xs > /var/cassandra/data/drc/queue.idxStatus-hb-196-Data.db > 00007fc7336bb000 22348K 0K 0K 0K 0K r-xs > /var/cassandra/data/drc/queue.idxInQueueTime-hb-175-Index.db > > > BRs > //Ares Tang > > > > -- > It's always darkest just before you are eaten by a grue. > >
