Is it normal for Java /Tomcat to keep checking for java_pid<nnnn>.hprof?
- by Chris
I was monitoring my JVM running Apache Tomcat 6, running on Windows, and I noticed that every 3 seconds or so the JVM process (C:\Tomcat\bin\tomcat6.exe) is polling to see whether or not
C:\Tomcatcat\java_pid3748.hprof
exists, where 3748 is the Windows process ID.
I haven't seen write to the hprof file, just test for existence.
(I'm using Sysinternals Process Monitor (procmon.exe) for this monitoring. In procmon the polling shows up as a QueryDirectory operation, which always returns Result "NO SUCH FILE".)
Is this normal, or is this a potential red flag? I gather that these hprof files are generated, perhaps among other times, when you enable the
-XX:+HeapDumpOnOutOfMemoryError
Java flag. I haven't enabled it myself, though I guess it could be enabled somehow in the Tomcat startup scripts.