[HBASE-14522] Document and/or disable hsperfdata GC pauses

• Type: Task
• Status: Closed
• Priority: Major
• Resolution: Abandoned
• Component/s: documentation, Performance
• Assignee: Unassigned
• Reporter: Nick Dimiduk
• Created: 30/Sep/15 10:44
• Updated: 01/Jul/22 21:38
• Resolved: 01/Jul/22 21:38

Description

The JVM by default exports statistics by mmap-ing a file in /tmp (hsperfdata). On Linux, modifying a memory mapped file can block until disk I/O completes, which can be hundreds of milliseconds. Since the JVM modifies these statistics during garbage collection and safepoints, this causes pauses that are hundreds of milliseconds long.

Via JVM mmap pause.

We should add -XX:+PerfDisableSharedMem to our default options as was apparently done in CASSANDRA-9242 and/or document the presence of this bug so operators know to use tmpfs.

Hat-tip vrodionov