[ https://issues.apache.org/jira/browse/HDFS-5693?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Ming Ma reassigned HDFS-5693: ----------------------------- Assignee: Ming Ma > Few NN metrics data points were collected via JMX when NN is under heavy load > ----------------------------------------------------------------------------- > > Key: HDFS-5693 > URL: https://issues.apache.org/jira/browse/HDFS-5693 > Project: Hadoop HDFS > Issue Type: Improvement > Components: namenode > Reporter: Ming Ma > Assignee: Ming Ma > Attachments: HADOOP-5693.patch, HDFS-5693.patch > > > JMX sometimes doesn’t return any value when NN is under heavy load. However, > that is when we would like to get metrics to help to diagnosis the issue. > When NN is under heavy load due to bad application or other reasons, it holds > FSNamesystem's writer lock for a long period of time. Many of the > FSNamesystem metrics require FSNamesystem's reader lock and thus can't be > processed. > This is a special case to improve the overall NN concurrency. -- This message was sent by Atlassian JIRA (v6.2#6252)