Hi Mao, Try to send a QUIT signal to the jvm. It will produce a java thread stack dump on STDOUT. The normal tomcat sart scripts redirect stdout to catalina.out, so the result goes there.
After "kill -QUIT PID" (replace PID by the pid of the process) you can inspect the dump in catalina.out to find out, what all the threads in your connector worker pool are doing. If your JVM is older than 1.4.2 or a very early 1.4.2 release, sending a QUIT signal might pose a risk on your process. All jvm releases of the last two years including patch releases of 1.4.2 can produce thread dumps without any problems. Regards, Rainer Ni Chen schrieb: > Hi Rainer, > > Thanks a lot for looking into this. I understand this is old configuration. > But it is in production, and I don't see any change log/fix related to this > issue in either later version of mod_jk or Tomcat 4. The other thing is we do > launch netstat after it hang, and we saw AJP Connector is listening, but > Telnet go timeout. I mean if it is not listening, I would expect message: > refused by remost host. > > Is ther any tool or system logs we can see/use to see why no ACK packet > returned back from server where Tomcat is running since we saw TCP connection > is in SYN_SENT on client side (Apache)? > > Thanks again, > Mao > > > > ----- Original Message ---- > From: Rainer Jung <[EMAIL PROTECTED]> > To: Tomcat Users List <users@tomcat.apache.org> > Sent: Tuesday, October 31, 2006 2:51:40 PM > Subject: Re: Tomcat Ajp13 Connector hang > > > Hi Mao (or Ni or Chen?), > > your environment seems *very* outdated. Please update to Tomcat 4.1.34 > und mod_jk 1.2.19. If the problem still shows up, please post relevant > parts of your configs (Apache and tomcat side) and check via netstat, if > tomcat still listens on the Ajp13 port. > > Regards, > > Rainer > > Ni Chen schrieb: >> Hi Folks, >> We are having an issue that Ajp13 Connector being unresponsive. It happened >> about once a week. We are running one Apache 2.0, three Tomcat 4.1.27 and >> mod_jk 1.2.5 / Ajp13 on HP 11i boxes. >> We noticed that every time Ajp13 Connector received an exception (see below) >> when setting socket options, serverSocket was closed and reopened, >> =========== >> serverSocket in Ajp13Connector got an exception when socket.setSoLinger(). >> 2006-10-24 15:31:31 Ajp13Connector[9015] accept: >> java.net.SocketException: Invalid Character In Attribute Name. >> at java.net.PlainSocketImpl.socketSetOption(Native Method) >> at java.net.PlainSocketImpl.setOption(PlainSocketImpl.java:240) >> at java.net.Socket.setSoLinger(Socket.java:817) >> at org.apache.ajp.tomcat4.Ajp13Connector.run(Ajp13Connector.java:891) >> at java.lang.Thread.run(Thread.java:534) >> 2006-10-24 15:31:31 Ajp13Connector[9015] run(): not stopped, so reopening >> server socket >> 2006-10-24 15:31:31 Ajp13Connector[9015] Opening server socket on all host >> IP addresses >> 2006-10-24 15:31:31 Ajp13Connector[9015] accepting socket... >> ========== >> Ajp13 Connector was not able to process new connection requests any more. If >> we telnet it, we got timeout, and socket status is SYN_SENT. If we restart >> Tomcat, it works again. >> Our Ajp13 Connector setting: >> <Connector className="org.apache.ajp.tomcat4.Ajp13Connector" >> port="9015" >> minProcessors="250" >> maxProcessors="250" >> acceptCount="50" >> debug="7"/> >> We don’t have special settings in worker.properties except >> worker.loadbalancer.stick_session=1 >> When this issue happens, Tomcat continues work on the established >> connections to handle requests, but eventually all sockets will be closed by >> Processors, and then Tomcat hang since no new connection could be >> established. However, we still see around 80 established connections in the >> netstat. >> Could it be other processes we forked in the tomcat that holding the >> connection, and then it caused socket file descriptor dead lock or >> unavailable? >> >> Any comments are welcome! >> Mao >> >> >> >> --------------------------------------------------------------------- >> To start a new topic, e-mail: users@tomcat.apache.org >> To unsubscribe, e-mail: [EMAIL PROTECTED] >> For additional commands, e-mail: [EMAIL PROTECTED] >> > > --------------------------------------------------------------------- > To start a new topic, e-mail: users@tomcat.apache.org > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > > > > --------------------------------------------------------------------- > To start a new topic, e-mail: users@tomcat.apache.org > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > --------------------------------------------------------------------- To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
