Re: [Tomcat] Can I see if 'maxThreads' is exceeded?
On 29/11/2010 22:21, Sylvain Laurent wrote: On 29 nov. 2010, at 15:01, Mark Thomas wrote: On 29/11/2010 13:57, sol myr wrote: Hi, I'm new to Tomcat management, and would appreciate help on the 'maxThreads' property of the Http Connector: 1) Please tell if I understood correctly: Suppose I configure 'maxThreads=100', and 130 users try to simultaneously access my Tomcat - then 100 users will be served immediately, and the other 30 will be put on hold? Is this correct? Yes. 2) Is there a way to monitor how many users are 'put on hold' (e.g. 50 on the above example)? No. It happens too low down the network stack for Tomcat to be able to get this information. Mark, correct me if I'm wrong, but I believe that actually with an Executor, the acceptor thread still accepts requests and enqueues them in a queue which is unbounded by default. You can monitor the size of this queue with JMX (attribute queueSize on the Executor's thread pool). What you refered to is when the acceptor thread does not keepup, the OS enqueues new TCP connections attempts up to a maximum (100 by default for the http basic IO connector). Executors aren't used by default. I was referring to the tcp backlog. Mark - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: [Tomcat] Can I see if 'maxThreads' is exceeded?
Sorry, correction: on section 2, I meant to say e.g. 30 on the above example (wrote '50' by mistake). Thanks again. --- On Mon, 11/29/10, sol myr solmy...@yahoo.com wrote: From: sol myr solmy...@yahoo.com Subject: [Tomcat] Can I see if 'maxThreads' is exceeded? To: users@tomcat.apache.org Date: Monday, November 29, 2010, 5:57 AM Hi, I'm new to Tomcat management, and would appreciate help on the 'maxThreads' property of the Http Connector: 1) Please tell if I understood correctly: Suppose I configure 'maxThreads=100', and 130 users try to simultaneously access my Tomcat - then 100 users will be served immediately, and the other 30 will be put on hold? Is this correct? 2) Is there a way to monitor how many users are 'put on hold' (e.g. 50 on the above example)? Can I ask tomcat log this information? Or is this information exposed on the 'manager'? Or via JConsole? Thanks.
Re: [Tomcat] Can I see if 'maxThreads' is exceeded?
On 29/11/2010 13:57, sol myr wrote: Hi, I'm new to Tomcat management, and would appreciate help on the 'maxThreads' property of the Http Connector: 1) Please tell if I understood correctly: Suppose I configure 'maxThreads=100', and 130 users try to simultaneously access my Tomcat - then 100 users will be served immediately, and the other 30 will be put on hold? Is this correct? Yes. 2) Is there a way to monitor how many users are 'put on hold' (e.g. 50 on the above example)? No. It happens too low down the network stack for Tomcat to be able to get this information. Can I ask tomcat log this information? No. Or is this information exposed on the 'manager'? Or via JConsole? No. No. Mark - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: [Tomcat] Can I see if 'maxThreads' is exceeded?
Mark Thomas wrote: On 29/11/2010 13:57, sol myr wrote: Hi, I'm new to Tomcat management, and would appreciate help on the 'maxThreads' property of the Http Connector: 1) Please tell if I understood correctly: Suppose I configure 'maxThreads=100', and 130 users try to simultaneously access my Tomcat - then 100 users will be served immediately, and the other 30 will be put on hold? Is this correct? Yes. 2) Is there a way to monitor how many users are 'put on hold' (e.g. 50 on the above example)? No. It happens too low down the network stack for Tomcat to be able to get this information. If you search Google for tcp listen queue size or tcp accept queue size (or SOMAXCONN), you will find more information about this. Depending on your O.S., there may exist utility programs allowing to display the current state for a given port/socket. - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: [Tomcat] Can I see if 'maxThreads' is exceeded?
André and Mark - thanks very much for the quick replies. --- On Mon, 11/29/10, André Warnier a...@ice-sa.com wrote: From: André Warnier a...@ice-sa.com Subject: Re: [Tomcat] Can I see if 'maxThreads' is exceeded? To: Tomcat Users List users@tomcat.apache.org Date: Monday, November 29, 2010, 6:21 AM Mark Thomas wrote: On 29/11/2010 13:57, sol myr wrote: Hi, I'm new to Tomcat management, and would appreciate help on the 'maxThreads' property of the Http Connector: 1) Please tell if I understood correctly: Suppose I configure 'maxThreads=100', and 130 users try to simultaneously access my Tomcat - then 100 users will be served immediately, and the other 30 will be put on hold? Is this correct? Yes. 2) Is there a way to monitor how many users are 'put on hold' (e.g. 50 on the above example)? No. It happens too low down the network stack for Tomcat to be able to get this information. If you search Google for tcp listen queue size or tcp accept queue size (or SOMAXCONN), you will find more information about this. Depending on your O.S., there may exist utility programs allowing to display the current state for a given port/socket. - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: [Tomcat] Can I see if 'maxThreads' is exceeded?
On 29 nov. 2010, at 15:01, Mark Thomas wrote: On 29/11/2010 13:57, sol myr wrote: Hi, I'm new to Tomcat management, and would appreciate help on the 'maxThreads' property of the Http Connector: 1) Please tell if I understood correctly: Suppose I configure 'maxThreads=100', and 130 users try to simultaneously access my Tomcat - then 100 users will be served immediately, and the other 30 will be put on hold? Is this correct? Yes. 2) Is there a way to monitor how many users are 'put on hold' (e.g. 50 on the above example)? No. It happens too low down the network stack for Tomcat to be able to get this information. Mark, correct me if I'm wrong, but I believe that actually with an Executor, the acceptor thread still accepts requests and enqueues them in a queue which is unbounded by default. You can monitor the size of this queue with JMX (attribute queueSize on the Executor's thread pool). What you refered to is when the acceptor thread does not keepup, the OS enqueues new TCP connections attempts up to a maximum (100 by default for the http basic IO connector). Can I ask tomcat log this information? No. Or is this information exposed on the 'manager'? Or via JConsole? No. No. No. yes (executor queueSize) Sylvain - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
