How to enable GC logs for Hiveserver2 / Metastore / Webhcat

[#1]

By default the GC logs are not enabled for Hive components. It is good to enable them to troubleshoot GC pauses on hiveserver2 instances.

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Hiveserver2 / Metastore:

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In Ambari navigate to the following path

Services -- > Hive -- > Configs -- > Advanced --> Advanced hive-env --> hive-env template

Add the following lines at the beginning,

if [[ "$SERVICE" == "hiveserver2" || "$SERVICE" == "metastore" ]]; then

HIVE_SERVERS_GC_LOG_OPTS="-Xloggc:{{hive_log_dir}}/gc.log-$SERVICE-`date +'%Y%m%d%H%M'` -verbose:gc -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -XX:+PrintGCDateStamps"

export HADOOP_OPTS="$HADOOP_OPTS $HIVE_SERVERS_GC_LOG_OPTS"

fi

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Webhact :

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In Ambari navigate to the following path

Services -- > Hive -- > Configs -- > Advanced --> Advanced webhcat-env --> webhcat-env template

Add the following lines at the bottom,

WEBHACAT_GC_LOG_OPTS="-Xloggc:{{templeton_log_dir}}/gc.log-webhcat-`date +'%Y%m%d%H%M'` -verbose:gc -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -XX:+PrintGCDateStamps"

export HADOOP_OPTS="$HADOOP_OPTS $WEBHACAT_GC_LOG_OPTS"

Save the changes in ambari and restart the hive services , it will enable the GC logs writing at the restart.

Thanks for the following articles. I changed the GC file name similar to namenode GC logs and kept all the GC variables in single parameter for simplicity.

https://community.hortonworks.com/content/supportkb/49404/how-to-setup-gc-log-for-hiveserver2.html

http://stackoverflow.com/questions/39888681/how-to-enable-gc-logging-for-apache-hiveserver2-metastor...