On Fri, Jan 14, 2011 at 2:13 PM, Victor Kabdebon <victor.kabde...@gmail.com> wrote: > Dear rajat, > > Yes it is possible, I have the same constraints. However I must warn you, > from what I see Cassandra memory consumption is not bounded in 0.6.X on > debian 64 Bit > > Here is an example of an instance launch in a node : > > root 19093 0.1 28.3 1210696 570052 ? Sl Jan11 9:08 > /usr/bin/java -ea -Xms128M -Xmx512M -XX:+UseParNewGC -XX:+UseConcMarkSweepGC > -XX:+CMSParallelRemarkEnabled -XX:SurvivorRatio=8 -XX:MaxTenuringThreshold=1 > -XX:CMSInitiatingOccupancyFraction=75 -XX:+UseCMSInitiatingOccupancyOnly > -XX:+HeapDumpOnOutOfMemoryError -Dcom.sun.management.jmxremote.port=8081 > -Dcom.sun.management.jmxremote.ssl=false > -Dcom.sun.management.jmxremote.authenticate=false > -Dstorage-config=bin/../conf -Dcassandra-foreground=yes -cp > bin/../conf:bin/../build/classes:bin/../lib/antlr-3.1.3.jar:bin/../lib/apache-cassandra-0.6.6.jar:bin/../lib/avro-1.2.0-dev.jar:bin/../lib/cassandra-javautils.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-io-1.4.jar:bin/../lib/commons-lang-2.4.jar:bin/../lib/commons-pool-1.5.4.jar:bin/../lib/google-collections-1.0.jar:bin/../lib/hadoop-core-0.20.1.jar:bin/../lib/hector-0.6.0-14.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/json-simple-1.1.jar:bin/../lib/libthrift-r917130.jar:bin/../lib/log4j-1.2.14.jar:bin/../lib/perf4j-0.9.12.jar:bin/../lib/slf4j-api-1.5.8.jar:bin/../lib/slf4j-log4j12-1.5.8.jar:bin/../lib/uuid-3.1.jar > org.apache.cassandra.thrift.CassandraDaemon > > Look at the second bold value, Xmx indicates the maximum memory that > cassandra can use; it is set to be 512, so it could easily fit into 1 Gb. > Now look at the first one, 570Mb > 512 Mb. Moreover if I come back in one > day the first value will be even higher. Probably around 610 Mb. Actually it > increases to the point where I need to restart it otherwise other program > are shut down by Linux for cassandra to further expand its memory usage... > > By the way it's a call to other cassandra users, am I the only one to > encounter this problem ? > > Best regards, > > Victor K. > > 2011/1/14 Rajat Chopra <rcho...@makara.com> >> >> Hello. >> >> >> >> According to JVM heap size topic at >> http://wiki.apache.org/cassandra/MemtableThresholds , Cassandra would need >> atleast 1G of memory to run. Is it possible to have a running Cassandra >> cluster with machines that have less than that memory… say 512M? >> >> I can live with slow transactions, no compactions etc, but do not want an >> OutOfMemory error. The reason for a smaller bound for Cassandra is that I >> want to leave room for other processes to run. >> >> >> >> Please help with specific parameters to tune. >> >> >> >> Thanks, >> >> Rajat >> >> >
-Xmx512M is not an overall memory limit. MMAP'ed files also consume memory. Try turning disk access mode to standard not (MMAP or MMAP_INDEX_ONLY).
