The Four Month Bug: JVM statistics cause garbage collection pauses about | archive [ 2015-March-24 16:56 ] TL;DR: 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 caus