John Zhuge created HADOOP-12908:
-----------------------------------
Summary: Make JvmPauseMonitor a singleton
Key: HADOOP-12908
URL: https://issues.apache.org/jira/browse/HADOOP-12908
Project: Hadoop Common
Issue Type: Improvement
Affects Versions: 2.7.2
Reporter: John Zhuge
Assignee: John Zhuge
Priority: Minor
Make JvmPauseMonitor a singleton just as JvmMetrics because there is no use
case to run multiple instances per JVM. No need for
{{TestMetrics$setPauseMonitor}} any more. Initialization code can be simplified.
For example, this code segment
{noformat}
pauseMonitor = new JvmPauseMonitor();
addService(pauseMonitor);
jm.setPauseMonitor(pauseMonitor);
{noformat}
becomes
{noformat}
addService(JvmPauseMonitor.INSTANCE);
{noformat}
And this code segment
{noformat}
pauseMonitor = new JvmPauseMonitor();
pauseMonitor.init(config);
pauseMonitor.start();
metrics.getJvmMetrics().setPauseMonitor(pauseMonitor);
{noformat}
becomes
{noformat}
pauseMonitor.INSTANCE.init(config);
pauseMonitor.INSTANCE.start();
{noformat}
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
