[HADOOP-15067] GC time percentage reported in JvmMetrics should be a gauge, not counter

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.0.0, 2.10.0
• Hadoop Flags: Reviewed
• Assignee: Misha Dmitriev
• Reporter: Misha Dmitriev
• Created: 22/Nov/17 19:41
• Updated: 28/Nov/17 18:54
• Resolved: 23/Nov/17 17:02

Description

A new GcTimeMonitor class has been recently added, and the corresponding metrics added in JvmMetrics.java, line 190:

    if (gcTimeMonitor != null) {
      rb.addCounter(GcTimePercentage,
          gcTimeMonitor.getLatestGcData().getGcTimePercentage());
    }

Since GC time percentage can go up and down, a gauge rather than counter should be used to report it. That is, addCounter should be replaced with addGauge above.

Issue Links

• is broken by: HADOOP-14960 Add GC time percentage monitor/alerter
• is related to: HBASE-19238 Port Hadoop's new GcTimeMonitor