http://blog.scoutapp.com/articles/2009/07/31/understanding-load-averages
http://docs.oracle.com/javase/7/docs/jre/api/management/extension/com/sun/management/OperatingSystemMXBean.html
Health monitor periodically prints logs about related internal metrics under when hazelcast is under load.
Under load means that memory usage is above threshold percentage or process/cpu load is above threshold.
Health monitor can be configured with system properties
"hazelcast.health.monitoring.level"
This property can be one of the following
NOISY => does not check threshold , always prints.
SILENT(default) => prints only if metrics are above threshold.
OFF => Does not print anything.
"hazelcast.health.monitoring.delay.seconds"
Time between printing two logs of health monitor. Default values is 30 seconds