Hi, all the points you've mentioned are important and have been considered. 5 minutes timeout for connection / keepAlive is a very long time, but this is OK for our web apps running in our intranet. But at the moment I'd be quite happy, if tomcat would make use of the defined timeouts and terminate the threads, that have been in keepalive state for more than 5 minutes.
But this does not happen! So my first goal is, to make tomcat respect the timeouts I define. The second goal then might be fine tuning the timeouts. Best regards, Michael -----Ursprüngliche Nachricht----- Von: André Warnier [mailto:a...@ice-sa.com] Gesendet: Freitag, 2. März 2012 13:01 An: Tomcat Users List Betreff: Re: Too many connections in keepalive state in jk threadpool Beier Michael wrote: > Hi all, > > we're running tomcat 7.0.23 on sun jdk 1.6.0_29, connected via ajp to httpd > 2.2.21 using mod_jk 1.2.32. > > I observed the behavior, that tomcat keeps threads in its ajp pool in > keepalive state, regardless of which timeouts (connectionTimeout and > keepAliveTimeout) are configured in tomcat. > I tested three connector configurations and with all I see connections in > tomcat server status where the "Time" value amounts up to several million > milliseconds, which is more than configured in > connectionTimeout/keepAliveTimeout. > This results in having 60-80 percent of the thread pool being in state > "keepAlive". > > 1) > <Connector port="8309" protocol="AJP/1.3" > maxThreads="200" redirectPort="8343" > tomcatAuthentication="false" > keepAliveTimeout="300000" connectionTimeout="300000" /> > 2) > <Connector port="8309" protocol="AJP/1.3" > maxThreads="200" redirectPort="8343" > tomcatAuthentication="false" > keepAliveTimeout="300000" /> > 3) > <Connector port="8309" protocol="AJP/1.3" > maxThreads="200" redirectPort="8343" > tomcatAuthentication="false" /> > > In mod_jk the connection_pool_timeout is set to the same value as > connectionTimeout (only in seconds, not milliseconds). > I verified that the values are set correctly querying the parameters via JMX. > > How can I avoid having so many threads in keepalive state - I don't have any > idea at the moment and can't see that there is an error in my configuration. Before discussing this, I find it useful to review the basics, such as in : http://en.wikipedia.org/wiki/HTTP_persistent_connection and http://tomcat.apache.org/connectors-doc/generic_howto/timeouts.html In other words, at the level of your front-end webserver (which I suppose you have, since you are talking about mod_jk and AJP), do you really need a long KeepAliveTimeout ? (and similarly at the level of your Tomcat <Connector>'s above). As per the documentation : connectionTimeout The number of milliseconds this Connector will wait, after accepting a connection, for the request URI line to be presented. The default value is 60000 (i.e. 60 seconds). keepAliveTimeout The number of milliseconds this Connector will wait for another AJP request before closing the connection. The default value is to use the value that has been set for the connectionTimeout attribute. In other words, - connectionTimeout defaults to 60 seconds - if you do not specify either one of them, then they both default to 60 seconds. - if you do specify connectionTimeout and not KeepAliveTimeout, then KeepAliveTimeout defaults to the same value as connectionTimeout. - your value above for KeepAliveTimeout (300000) means 5 minutes Do you really want one Tomcat thread to wait for 5 minutes doing nothing, just in case the browser would decide to send another request on the same connection ? And do you really want, when a browser creates its initial TCP connection to your webserver, to give it 60 seconds (or 5 mintes !) before it even starts sending its HTTP request on that connection ? --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
