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stack commented on HBASE-4386: ------------------------------ This seems reasonable. All other accesses on tasks are synchronized on this. +1. > NPE in TaskMonitor > ------------------ > > Key: HBASE-4386 > URL: https://issues.apache.org/jira/browse/HBASE-4386 > Project: HBase > Issue Type: Bug > Affects Versions: 0.92.0 > Reporter: Todd Lipcon > Assignee: Todd Lipcon > Priority: Critical > Fix For: 0.92.0 > > Attachments: hbase-4386.txt > > > Saw the following hitting /rs-status > <pre> INTERNAL_SERVER_ERROR</pre></p><h3>Caused > by:</h3><pre>java.lang.NullPointerException > at > org.apache.hadoop.hbase.monitoring.TaskMonitor.purgeExpiredTasks(TaskMonitor.java:97) > at > org.apache.hadoop.hbase.monitoring.TaskMonitor.getTasks(TaskMonitor.java:127) > at > org.apache.hbase.tmpl.common.TaskMonitorTmplImpl.renderNoFlush(TaskMonitorTmplImpl.java:50) > at > org.apache.hbase.tmpl.common.TaskMonitorTmpl.renderNoFlush(TaskMonitorTmpl.java:170) > at > org.apache.hbase.tmpl.regionserver.RSStatusTmplImpl.renderNoFlush(RSStatusTmplImpl.java:70) > at > org.apache.hbase.tmpl.regionserver.RSStatusTmpl.renderNoFlush(RSStatusTmpl.java:176) > at > org.apache.hbase.tmpl.regionserver.RSStatusTmpl.render(RSStatusTmpl.java:167) > at > org.apache.hadoop.hbase.regionserver.RSStatusServlet.doGet(RSStatusServlet.java:48) -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira