To add some more detail, we are using Java 1.8 openJDK, and Hadoop 3.2.0.
These new JVM options were also added to HDFS_DATANODE_OPTS and
HDFS_NAMENODE_OPTs in hadoop-env,sh. This eliminated a replication warning
that kept occurring on our cluster.
Here are the rest of the JAVA_OPTS in accumulo-env.sh for reference as what
is normally there by default:
'-XX:CMSInitiatingOccupancyFraction=75'
'-XX:+CMSClassUnloadingEnabled'
'-XX:OnOutOfMemoryError=kill -9 %p'
'-XX:-OmitStackTraceInFastThrow'
'-Djava.net.preferIPv4Stack=true'
"-Daccumulo.native.lib.path=${lib}/native")
On Fri, Mar 22, 2019 at 9:29 AM Jeffrey Zeiberg <[email protected]> wrote:
> Jeffrey Manno (ASRC Federal) and Jeffrey Zeiberg (ASRC Federal) have
> discovered that adding a few new JVM options to the JAVA_OPTS set prevented
> crashing and increase system performance.
>
> They were added after line 68 in accumulo-env.sh. They are:
> 'server'
> '-XX:+UseParallelOldGC'
> '-XX:NewRatio=3'
> '-XX:AggressiveHeap'
>
> The machines we are using are 7 year old machines with 8G of main memory,
> between 500G - 1T HDD and Intel I5 or I7 processors.
>
> Maybe these parameters should be made in the Accumulo 2.0 distributions
> accumulo-env.sh file?
>
> Comments?
>
