-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Alexander,
On 7/13/12 4:34 AM, Alexander Shutyaev wrote: > I've encountered a problem with an embedded tomcat. That sound serious. > The thread dump shows a lot of threads (106 out of 722 total) are > blocked waiting for a monitor > org.apache.tomcat.util.threads.ThreadPool. Okay. You have maxThreads=1000. Is 106 an unusual number to be idling in the pool? > The locking thread is itself blocked on a monitor > (0x00007f33e30ef000) but I can't find this monitor in the dump > which is a little bit confusing. I would have looked for that monitor, but you didn't provide the full dump, so I'm just as confused as you. > I thought of a deadlock, but there are no deadlocks detected in the > dump. My version, config and thread stacktraces are below. Can > someone help identifying the source of the problem? Threads in a BLOCKED state are not a problem. Can you maybe describe your problem in a different way? Has Tomcat stopped responding to requests? Has CPU usage spiked such that Tomcat/JVM are consuming the entire CPU resources? > 5.5.23 Upgrade. I would add something like 1.5.12 to that version up there if you could. If you are scared of changing major revisions, then try adding 0.0.7 instead. Note that embedding Tomcat 7 is deliriously simple when compared to the complex work of embedding past versions: you may significantly simplify your own code by upgrading and making the appropriate changes. > *server.xml* > > <Server port="8005" shutdown="SHUTDOWN"> <GlobalNamingResources /> > <Service name="Catalina"> <Connector port="9090" > maxHttpHeaderSize="8192" maxThreads="1000" With maxThreads=1000, you might benefit from ... well, at this point 5+ years of performance and API improvements, including NIO connectors which might allow you to accept more connections while utilizing fewer threads. > minSpareThreads="25" maxSpareThreads="75" maxThreads=1000 maxSpareThreads=75? I guess you are expecting a lot of thread-pool thrashing. > enableLookups="false" redirectPort="8443" acceptCount="100" > connectionTimeout="20000" disableUploadTimeout="true" > maxPostSize="0" /> No POSTs? That's odd. > <Engine name="Catalina" defaultHost="localhost"> <Host > name="localhost" appBase="webapps" unpackWARs="false" > autoDeploy="false" xmlValidation="false" xmlNamespaceAware="false" > /> </Engine> </Service> </Server> > > *Locking thread stacktrace* > > "http-9090-Processor755" daemon prio=10 tid=0x00007f33fde43000 > nid=0x5ca8 waiting for monitor entry [0x00007f33e30ef000] > java.lang.Thread.State: BLOCKED (on object monitor) at > org.apache.tomcat.util.threads.ThreadPool. > returnController(ThreadPool.java:440) - locked <0x0000000685e71038> > (a org.apache.tomcat.util. threads.ThreadPool) at > org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run( > ThreadPool.java:712) at java.lang.Thread.run(Thread.java:679) > > *Example of a waiting thread stacktrace* > > "http-9090-Processor504" daemon prio=10 tid=0x000000000432b800 > nid=0x5329 waiting for monitor entry [0x00007f3400218000] > java.lang.Thread.State: BLOCKED (on object monitor) at > org.apache.tomcat.util.threads.ThreadPool. > returnController(ThreadPool.java:440) - waiting to lock > <0x0000000685e71038> (a org.apache.tomcat.util. > threads.ThreadPool) at > org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run( > ThreadPool.java:712) at java.lang.Thread.run(Thread.java:679) > ThreadPool.returnController is called when threads are being returned to the pool. Do these two threads stay stuck this way if you take several thread dumps over a few seconds? - -chris -----BEGIN PGP SIGNATURE----- Version: GnuPG/MacGPG2 v2.0.17 (Darwin) Comment: GPGTools - http://gpgtools.org Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAlAAIaIACgkQ9CaO5/Lv0PBnEwCgrIChmJrfQUBCCyUQTY7N7BXR p1cAoMCi1VPWXsEQUPyoN2E8k+rZq2gG =/Ggc -----END PGP SIGNATURE----- --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
