SPARK_JAVA_OPTS is deprecated in 1.0, though it works fine if you donโt mind the WARNING in the logs
you can set spark.executor.extraJavaOpts in your SparkConf obj Best, -- Nan Zhu On Sunday, June 15, 2014 at 12:13 PM, Hao Wang wrote: > Hi, Wei > > You may try to set JVM opts in spark-env.sh (http://spark-env.sh) as follow > to prevent or mitigate GC pause: > > export SPARK_JAVA_OPTS="-XX:-UseGCOverheadLimit -XX:+UseConcMarkSweepGC > -Xmx2g -XX:MaxPermSize=256m" > > There are more options you could add, please just Google :) > > > Regards, > Wang Hao(็็) > > CloudTeam | School of Software Engineering > Shanghai Jiao Tong University > Address:800 Dongchuan Road, Minhang District, Shanghai, 200240 > Email:wh.s...@gmail.com (mailto:wh.s...@gmail.com) > > > > > > > On Sun, Jun 15, 2014 at 10:24 AM, Wei Tan <w...@us.ibm.com > (mailto:w...@us.ibm.com)> wrote: > > Hi, > > > > I have a single node (192G RAM) stand-alone spark, with memory > > configuration like this in spark-env.sh (http://spark-env.sh) > > > > SPARK_WORKER_MEMORY=180g > > SPARK_MEM=180g > > > > > > In spark-shell I have a program like this: > > > > val file = sc.textFile("/localpath") //file size is 40G > > file.cache() > > > > > > val output = file.map(line => extract something from line) > > > > output.saveAsTextFile (...) > > > > > > When I run this program again and again, or keep trying file.unpersist() > > --> file.cache() --> output.saveAsTextFile(), the run time varies a lot, > > from 1 min to 3 min to 50+ min. Whenever the run-time is more than 1 min, > > from the stage monitoring GUI I observe big GC pause (some can be 10+ min). > > Of course when run-time is "normal", say ~1 min, no significant GC is > > observed. The behavior seems somewhat random. > > > > Is there any JVM tuning I should do to prevent this long GC pause from > > happening? > > > > > > > > I used java-1.6.0-openjdk.x86_64, and my spark-shell process is something > > like this: > > > > root 10994 1.7 0.6 196378000 1361496 pts/51 Sl+ 22:06 0:12 > > /usr/lib/jvm/java-1.6.0-openjdk.x86_64/bin/java -cp > > ::/home/wtan/scala/spark-1.0.0-bin-hadoop1/conf:/home/wtan/scala/spark-1.0.0-bin-hadoop1/lib/spark-assembly-1.0.0-hadoop1.0.4.jar:/home/wtan/scala/spark-1.0.0-bin-hadoop1/lib/datanucleus-core-3.2.2.jar:/home/wtan/scala/spark-1.0.0-bin-hadoop1/lib/datanucleus-rdbms-3.2.1.jar:/home/wtan/scala/spark-1.0.0-bin-hadoop1/lib/datanucleus-api-jdo-3.2.1.jar > > -XX:MaxPermSize=128m -Djava.library.path= -Xms180g -Xmx180g > > org.apache.spark.deploy.SparkSubmit spark-shell --class > > org.apache.spark.repl.Main > > > > Best regards, > > Wei > > > > --------------------------------- > > Wei Tan, PhD > > Research Staff Member > > IBM T. J. Watson Research Center > > http://researcher.ibm.com/person/us-wtan
