mmapping only consumes memory that the OS can afford to feed it. On Fri, Jan 14, 2011 at 7:29 PM, Edward Capriolo <edlinuxg...@gmail.com> wrote: > 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). >
-- Jonathan Ellis Project Chair, Apache Cassandra co-founder of Riptano, the source for professional Cassandra support http://riptano.com
