[ https://issues.apache.org/jira/browse/AMBARI-18694?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Xiaobing Zhou reassigned AMBARI-18694: -------------------------------------- Assignee: Xiaobing Zhou > Add JVM settings of forcing garbage collections to release DataNode heap > ------------------------------------------------------------------------ > > Key: AMBARI-18694 > URL: https://issues.apache.org/jira/browse/AMBARI-18694 > Project: Ambari > Issue Type: Improvement > Reporter: Xiaobing Zhou > Assignee: Xiaobing Zhou > > As HDFS-11047 reported, DirectoryScanner does scan by deep copying > FinalizedReplica. In a deployment with 500,000+ blocks, we've seen the DN > heap usage being accumulated to high peaks very quickly. Deep copies of > FinalizedReplica will make DN heap usage even worse if directory scans are > scheduled more frequently. > Another factor is that huge number of ScanInfo instances corresponding to > HDFS blocks are lingering in garbage to eat many heap memories until a full > GC takes place. > This proposes adding JVM settings to force GC more frequently to release > DataNode heap consumed as a result of two aforementioned reasons, i.e. add > the options to HADOOP_DATANODE_OPTS > {noformat} > -XX:CMSInitiatingOccupancyFraction=70 -XX:+UseCMSInitiatingOccupancyOnly > -XX:ConcGCThreads=8 -XX:+UseConcMarkSweepGC > {noformat} -- This message was sent by Atlassian JIRA (v6.3.4#6332)