-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Neil,
On 11/12/2009 2:41 PM, Goldsmith, Neil J. (Neil) wrote: > That graph of threads, total mem and handles for this behavior looks > like a staircase. Do they all jump up at the same time? Does your thread count increase? Does your number of handles increase? Does your used memory increase? I know you said all these things, but do they all increase or just one of them (that was a bit unclear... I've never seen a graph of "threads, total mem and handles" so I suspect you meant to say that the graph of each one independently jumps up). > All at once, we about double these values. If your thread count doubles, I would expect your number of handles to quadruple (each worker thread typically has an input and output handle, so handles ~= 2*threads). > Looking at logs from our servlets, there is no unexpected behavior > during these huge jumps. They are chugging along handling the > traffic as expected and don't have any delays or out of the ordinary > behavior. Are you re-deploying your web application or anything weird like that at these times? Do you have any timed events scheduled such as a Quartz job that does something at intervals? What about cache expirations that your webapp might be doing? I wonder if something happens suddenly that causes a significant chunk of objects to re-initialize themselves. Do you use a remote database? Is it possible that a piece of network hardware is terminating all your JDBC connections at once and they are being re-initialized? I would expect the old connections to terminate and be cleaned-up, but it might depend on your environment and configuration. Do you ever run out of memory? > Does this sound like a GC issue? Unlikely. If it were just memory "problems", then maybe. But since you are seeing unexpected thread and handle activity, it's unlikely to be GC-related. I'd be interested in seeing what your GC graph looks like, though. Even if your JVM process appears to eat memory without bound (like a "staircase"), it's possible that your GC graph looks like a much more reasonable saw-toothed graph. See Chuck's suggestions for tools you might want to use. - -chris -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAkr9t2wACgkQ9CaO5/Lv0PBJ0ACZAfkv0zcOmPdlFBaSMUgX15Nk XhsAn2NPUSAJuVixJDDCmfbK4KAmrgZA =87u8 -----END PGP SIGNATURE----- --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
