Hi, we are using cassandra 2.2.8 version in production. we are seeing resident memory of cassndra process is very high 40G while heap size is only 8GB.
root 23339 1 80 Nov11 ? 2-09:38:08 /opt/java8/bin/java -ea -javaagent:bin/../lib/jamm-0.3.0.jar -XX:+CMSClassUnloadingEnabled -XX:+UseThreadPriorities -XX:ThreadPriorityPolicy=42* -Xms8192M -Xmx8192M -Xmn2048M* -XX:+HeapDumpOnOutOfMemoryError -Xss256k -XX:StringTableSize=1000003 -XX:+UseParNewGC -XX:+UseConcMarkSweepGC -XX:+CMSParallelRemarkEnabled -XX:SurvivorRatio=8 -XX:MaxTenuringThreshold=1 -XX:CMSInitiatingOccupancyFraction=75 -XX:+UseCMSInitiatingOccupancyOnly -XX:+UseTLAB -XX:+PerfDisableSharedMem -XX:CompileCommandFile=bin/../conf/hotspot_compiler -XX:CMSWaitDuration=10000 -XX:+CMSParallelInitialMarkEnabled -XX:+CMSEdenChunksRecordAlways -XX:CMSWaitDuration=10000 -XX:+UseCondCardMark -XX:+PrintGCDetails -XX:+PrintGCDateStamps -XX:+PrintHeapAtGC -XX:+PrintTenuringDistribution -XX:+PrintGCApplicationStoppedTime -XX:+PrintPromotionFailure -Xloggc:bin/../logs/gc.log -XX:+UseGCLogFileRotation -XX:NumberOfGCLogFiles=10 -XX:GCLogFileSize=10M -Djava.net.preferIPv4Stack=true -Dcassandra.jmx.local.port=7199 -XX:+DisableExplicitGC -Djava.library.path=bin/../lib/sigar-bin -javaagent:/myntra/currentCassandra/lib/agent-1.2.jar=statsd.myntra.com:8125 -Dlogback.configurationFile=logback.xml -Dcassandra.logdir=bin/../logs -Dcassandra.storagedir=bin/../data -cp bin/../conf:bin/../build/classes/main:bin/../build/classes/thrift:bin/../lib/agent-1.2.jar:bin/../lib/airline-0.6.jar:bin/../lib/antlr-runtime-3.5.2.jar:bin/../lib/apache-cassandra-2.2.8.jar:bin/../lib/apache-cassandra-clientutil-2.2.8.jar:bin/../lib/apache-cassandra-thrift-2.2.8.jar:bin/../lib/cassandra-driver-core-2.2.0-rc2-SNAPSHOT-20150617-shaded.jar:bin/../lib/commons-cli-1.1.jar:bin/../lib/commons-codec-1.2.jar:bin/../lib/commons-lang3-3.1.jar:bin/../lib/commons-math3-3.2.jar:bin/../lib/compress-lzf-0.8.4.jar:bin/../lib/concurrentlinkedhashmap-lru-1.4.jar:bin/../lib/crc32ex-0.1.1.jar:bin/../lib/disruptor-3.0.1.jar:bin/../lib/ecj-4.4.2.jar:bin/../lib/guava-16.0.jar:bin/../lib/high-scale-lib-1.0.6.jar:bin/../lib/jackson-core-asl-1.9.2.jar:bin/../lib/jackson-mapper-asl-1.9.2.jar:bin/../lib/jamm-0.3.0.jar:bin/../lib/java-statsd-client-3.1.0.jar:bin/../lib/javax.inject.jar:bin/../lib/jbcrypt-0.3m.jar:bin/../lib/jcl-over-slf4j-1.7.7.jar:bin/../lib/jna-4.0.0.jar:bin/../lib/joda-time-2.4.jar:bin/../lib/json-simple-1.1.jar:bin/../lib/libthrift-0.9.2.jar:bin/../lib/log4j-over-slf4j-1.7.7.jar:bin/../lib/logback-classic-1.1.3.jar:bin/../lib/logback-core-1.1.3.jar:bin/../lib/lz4-1.3.0.jar:bin/../lib/metrics-core-2.2.0.jar:bin/../lib/metrics-core-3.1.0.jar:bin/../lib/metrics-jvm-3.1.0.jar:bin/../lib/metrics-logback-3.1.0.jar:bin/../lib/metrics-statsd-2.3.0.jar:bin/../lib/netty-all-4.0.23.Final.jar:bin/../lib/ohc-core-0.3.4.jar:bin/../lib/ohc-core-j8-0.3.4.jar:bin/../lib/reporter-config3-3.0.0.jar:bin/../lib/reporter-config-base-3.0.0.jar:bin/../lib/sigar-1.6.4.jar:bin/../lib/slf4j-api-1.7.7.jar:bin/../lib/snakeyaml-1.11.jar:bin/../lib/snappy-java-1.1.1.7.jar:bin/../lib/ST4-4.0.8.jar:bin/../lib/stream-2.5.2.jar:bin/../lib/super-csv-2.1.0.jar:bin/../lib/thrift-server-0.3.7.jar:bin/../lib/jsr223/*/*.jar org.apache.cassandra.service.CassandraDaemon below is the output of top command. PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 23339 root 20 0 295g * 39g 28g* S 107.5 63.5 3458:31 java *I couldn't understand why cassandra process is using so much resident memory while heap size is only 8gb. Any insight??*
