You are viewing a plain text version of this content. The canonical link for it is here.
Posted to user@cassandra.apache.org by Daning Wang <da...@netseer.com> on 2012/01/03 21:53:08 UTC
Cassandra memory usage
I have Cassandra server which has JVM setting -Xms4G -Xmx4G, but why top
reports 15G RES memory and 11G SHR memory usage? I understand that -Xmx4G
is only for the heap size. but it is strange that OS reports 2.5 times
memory usage. Are there a lot of memory used by JNI? Please help to explain
this.
cassy 2549 39.7 66.1 163805536 16324648 ? Sl Jan02 338:48
/usr/local/cassy/java/current/bin/java -ea
-javaagent:./../lib/jamm-0.2.2.jar -XX:+UseThreadPriorities
-XX:ThreadPriorityPolicy=42* -Xms4G -Xmx4G
-Xmn1G*-XX:+HeapDumpOnOutOfMemoryError -Xss128k -XX:+UseParNewGC
-XX:+UseConcMarkSweepGC -XX:+CMSParallelRemarkEnabled -XX:SurvivorRatio=8
-XX:MaxTenuringThreshold=10 -XX:CMSInitiatingOccupancyFraction=75
-XX:+UseCMSInitiatingOccupancyOnly -Djava.net.preferIPv4Stack=true
-Dcom.sun.management.jmxremote.port=7199
-Dcom.sun.management.jmxremote.ssl=false
-Dcom.sun.management.jmxremote.authenticate=false -Dmx4jport=8085
-Djava.rmi.server.hostname=10.210.101.106
-Dlog4j.configuration=log4j-server.properties
-Dlog4j.defaultInitOverride=true
-Dpasswd.properties=./../conf/passwd.properties -cp
./../conf:./../build/classes/main:./../build/classes/thrift:./../lib/antlr-3.2.jar:./../lib/apache-cassandra-0.8.6.jar:./../lib/apache-cassandra-thrift-0.8.6.jar:./../lib/avro-1.4.0-fixes.jar:./../lib/avro-1.4.0-sources-fixes.jar:./../lib/commons-cli-1.1.jar:./../lib/commons-codec-1.2.jar:./../lib/commons-collections-3.2.1.jar:./../lib/commons-lang-2.4.jar:./../lib/concurrentlinkedhashmap-lru-1.1.jar:./../lib/guava-r08.jar:./../lib/high-scale-lib-1.1.2.jar:./../lib/jackson-core-asl-1.4.0.jar:./../lib/jackson-mapper-asl-1.4.0.jar:./../lib/jamm-0.2.2.jar:./../lib/jline-0.9.94.jar:./../lib/jna.jar:./../lib/json-simple-1.1.jar:./../lib/libthrift-0.6.jar:./../lib/log4j-1.2.16.jar:./../lib/mx4j-tools.jar:./../lib/servlet-api-2.5-20081211.jar:./../lib/slf4j-api-1.6.1.jar:./../lib/slf4j-log4j12-1.6.1.jar:./../lib/snakeyaml-1.6.jar
org.apache.cassandra.thrift.CassandraDaemon
Top
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+
COMMAND
2549 cassy 21 0 156g * 15g 11g *S 66.9 65.5 338:02.72 java
Thank you in advance,
Daning
Re: Cassandra memory usage
Posted by Narendra Sharma <na...@gmail.com>.
See http://wiki.apache.org/cassandra/FAQ#mmap
Also, the discussion on
http://comments.gmane.org/gmane.comp.db.cassandra.user/14080
Hopefully these will answer your question.
-Naren
On Tue, Jan 3, 2012 at 12:53 PM, Daning Wang <da...@netseer.com> wrote:
> I have Cassandra server which has JVM setting -Xms4G -Xmx4G, but why top
> reports 15G RES memory and 11G SHR memory usage? I understand that -Xmx4G
> is only for the heap size. but it is strange that OS reports 2.5 times
> memory usage. Are there a lot of memory used by JNI? Please help to explain
> this.
>
> cassy 2549 39.7 66.1 163805536 16324648 ? Sl Jan02 338:48
> /usr/local/cassy/java/current/bin/java -ea
> -javaagent:./../lib/jamm-0.2.2.jar -XX:+UseThreadPriorities
> -XX:ThreadPriorityPolicy=42* -Xms4G -Xmx4G -Xmn1G*-XX:+HeapDumpOnOutOfMemoryError -Xss128k -XX:+UseParNewGC
> -XX:+UseConcMarkSweepGC -XX:+CMSParallelRemarkEnabled -XX:SurvivorRatio=8
> -XX:MaxTenuringThreshold=10 -XX:CMSInitiatingOccupancyFraction=75
> -XX:+UseCMSInitiatingOccupancyOnly -Djava.net.preferIPv4Stack=true
> -Dcom.sun.management.jmxremote.port=7199
> -Dcom.sun.management.jmxremote.ssl=false
> -Dcom.sun.management.jmxremote.authenticate=false -Dmx4jport=8085
> -Djava.rmi.server.hostname=10.210.101.106
> -Dlog4j.configuration=log4j-server.properties
> -Dlog4j.defaultInitOverride=true
> -Dpasswd.properties=./../conf/passwd.properties -cp
> ./../conf:./../build/classes/main:./../build/classes/thrift:./../lib/antlr-3.2.jar:./../lib/apache-cassandra-0.8.6.jar:./../lib/apache-cassandra-thrift-0.8.6.jar:./../lib/avro-1.4.0-fixes.jar:./../lib/avro-1.4.0-sources-fixes.jar:./../lib/commons-cli-1.1.jar:./../lib/commons-codec-1.2.jar:./../lib/commons-collections-3.2.1.jar:./../lib/commons-lang-2.4.jar:./../lib/concurrentlinkedhashmap-lru-1.1.jar:./../lib/guava-r08.jar:./../lib/high-scale-lib-1.1.2.jar:./../lib/jackson-core-asl-1.4.0.jar:./../lib/jackson-mapper-asl-1.4.0.jar:./../lib/jamm-0.2.2.jar:./../lib/jline-0.9.94.jar:./../lib/jna.jar:./../lib/json-simple-1.1.jar:./../lib/libthrift-0.6.jar:./../lib/log4j-1.2.16.jar:./../lib/mx4j-tools.jar:./../lib/servlet-api-2.5-20081211.jar:./../lib/slf4j-api-1.6.1.jar:./../lib/slf4j-log4j12-1.6.1.jar:./../lib/snakeyaml-1.6.jar
> org.apache.cassandra.thrift.CassandraDaemon
>
>
> Top
>
> PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+
> COMMAND
>
> 2549 cassy 21 0 156g * 15g 11g *S 66.9 65.5 338:02.72 java
>
>
> Thank you in advance,
>
>
> Daning
>
--
Narendra Sharma
Software Engineer
*http://www.aeris.com <http://www.persistentsys.com>*
*http://narendrasharma.blogspot.com/*