[HBASE-24752] NPE/500 accessing webui on master startup

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.3.0
• Fix Version/s: 3.0.0-alpha-1, 2.3.1, 2.4.0, 2.2.6
• Component/s: master
• Hadoop Flags: Reviewed
• Assignee: wenfeiyi666
• Reporter: Nick Dimiduk
• Created: 21/Jul/20 19:09
• Updated: 26/Aug/20 05:49
• Resolved: 29/Jul/20 15:00

Description

I got a 500 error while accessing the master web ui (non-backup master) during startup.

2020-07-21 18:56:39,762 WARN org.eclipse.jetty.servlet.ServletHandler: /master-status
java.lang.NullPointerException
        at org.apache.hadoop.hbase.tmpl.master.MasterStatusTmplImpl.renderNoFlush(MasterStatusTmplImpl.java:339)
        at org.apache.hadoop.hbase.tmpl.master.MasterStatusTmpl.renderNoFlush(MasterStatusTmpl.java:397)
        at org.apache.hadoop.hbase.tmpl.master.MasterStatusTmpl.render(MasterStatusTmpl.java:388)
        at org.apache.hadoop.hbase.master.MasterStatusServlet.doGet(MasterStatusServlet.java:79)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:687)
...

MasterStatusTmplImpl.java:339 appears to align with MasterStatusTmpl.jamon:227:

          <%if master.getMasterCoprocessorHost().findCoprocessor("RSGroupAdminEndpoint") != null &&
            serverManager.getOnlineServersList().size() > 0 %>

Issue Links

• links to: GitHub Pull Request #2148