Programmatically retrieve number of tomcat connections
Tomcat 7 Is there a way via a Java servlet to get the number of tomcat connections? Thanks, Lance Campbellhttp://illinois.edu/person/lance Software Architect Web Services at Public Affairs 217-333-0382 [University of Illinois at Urbana-Champaign logo]http://illinois.edu/
Re: Programmatically retrieve number of tomcat connections
On 31/07/2014 17:06, Campbell, Lance wrote: Tomcat 7 Is there a way via a Java servlet to get the number of tomcat connections? Connections from what to what in what state? With or without non-Servlet API calls? Mark - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
RE: Programmatically retrieve number of tomcat connections
Good question. I would like to have a servlet that would return to me the number of tomcat HTTP connections. I know you can do this via a Linux console command. But I would prefer to do it via a servlet. Thanks, Lance Campbell Software Architect Web Services at Public Affairs 217-333-0382 -Original Message- From: Mark Thomas [mailto:ma...@apache.org] Sent: Thursday, July 31, 2014 11:10 AM To: Tomcat Users List Subject: Re: Programmatically retrieve number of tomcat connections On 31/07/2014 17:06, Campbell, Lance wrote: Tomcat 7 Is there a way via a Java servlet to get the number of tomcat connections? Connections from what to what in what state? With or without non-Servlet API calls? Mark - 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
RE: Programmatically retrieve number of tomcat connections
Write a simple ServletFilter On Jul 31, 2014 9:33 AM, Campbell, Lance la...@illinois.edu wrote: Good question. I would like to have a servlet that would return to me the number of tomcat HTTP connections. I know you can do this via a Linux console command. But I would prefer to do it via a servlet. Thanks, Lance Campbell Software Architect Web Services at Public Affairs 217-333-0382 -Original Message- From: Mark Thomas [mailto:ma...@apache.org] Sent: Thursday, July 31, 2014 11:10 AM To: Tomcat Users List Subject: Re: Programmatically retrieve number of tomcat connections On 31/07/2014 17:06, Campbell, Lance wrote: Tomcat 7 Is there a way via a Java servlet to get the number of tomcat connections? Connections from what to what in what state? With or without non-Servlet API calls? Mark - 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
RE: Programmatically retrieve number of tomcat connections
Could you elaborate a little? How do you actually get the number of HTTP connections? Thanks, Lance Campbell Software Architect Web Services at Public Affairs 217-333-0382 -Original Message- From: Igal Sapir [mailto:i...@getrailo.org] Sent: Thursday, July 31, 2014 11:35 AM To: Tomcat Users List Subject: RE: Programmatically retrieve number of tomcat connections Write a simple ServletFilter On Jul 31, 2014 9:33 AM, Campbell, Lance la...@illinois.edu wrote: Good question. I would like to have a servlet that would return to me the number of tomcat HTTP connections. I know you can do this via a Linux console command. But I would prefer to do it via a servlet. Thanks, Lance Campbell Software Architect Web Services at Public Affairs 217-333-0382 -Original Message- From: Mark Thomas [mailto:ma...@apache.org] Sent: Thursday, July 31, 2014 11:10 AM To: Tomcat Users List Subject: Re: Programmatically retrieve number of tomcat connections On 31/07/2014 17:06, Campbell, Lance wrote: Tomcat 7 Is there a way via a Java servlet to get the number of tomcat connections? Connections from what to what in what state? With or without non-Servlet API calls? Mark - 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
Re: Programmatically retrieve number of tomcat connections
On 31/07/2014 17:56, Campbell, Lance wrote: Could you elaborate a little? How do you actually get the number of HTTP connections? You can't do this with a Filter. You can determine the number of active requests for an application but connection != active request and application != Tomcat server. There is no standard Servlet API for the information you want. Mark Thanks, Lance Campbell Software Architect Web Services at Public Affairs 217-333-0382 -Original Message- From: Igal Sapir [mailto:i...@getrailo.org] Sent: Thursday, July 31, 2014 11:35 AM To: Tomcat Users List Subject: RE: Programmatically retrieve number of tomcat connections Write a simple ServletFilter On Jul 31, 2014 9:33 AM, Campbell, Lance la...@illinois.edu wrote: Good question. I would like to have a servlet that would return to me the number of tomcat HTTP connections. I know you can do this via a Linux console command. But I would prefer to do it via a servlet. Thanks, Lance Campbell Software Architect Web Services at Public Affairs 217-333-0382 -Original Message- From: Mark Thomas [mailto:ma...@apache.org] Sent: Thursday, July 31, 2014 11:10 AM To: Tomcat Users List Subject: Re: Programmatically retrieve number of tomcat connections On 31/07/2014 17:06, Campbell, Lance wrote: Tomcat 7 Is there a way via a Java servlet to get the number of tomcat connections? Connections from what to what in what state? With or without non-Servlet API calls? Mark - 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 - 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
Re: Programmatically retrieve number of tomcat connections
well -- Mark surely knows much better than I do -- so take into account what he wrote, but I was already writing this so I decided to send anyway, and for most application it should work fine IMO: 1) you create a class that implements the Filter interface and maintains the count in an AtomicLong object. 2) you increment the AtomicLong before the call to chain.doFilter() and decrement it after that call. 3) you add a way to get the value, either with a public method or by setting the value to a Servlet Attribute. see more about Filters at http://www.oracle.com/technetwork/java/filters-137243.html another way I can think of is to get all the threads in the JVM with Thread.getAllStackTraces(), loop over them, and check their names for example. On 7/31/2014 10:01 AM, Mark Thomas wrote: On 31/07/2014 17:56, Campbell, Lance wrote: Could you elaborate a little? How do you actually get the number of HTTP connections? You can't do this with a Filter. You can determine the number of active requests for an application but connection != active request and application != Tomcat server. There is no standard Servlet API for the information you want. Mark Thanks, Lance Campbell Software Architect Web Services at Public Affairs 217-333-0382 -Original Message- From: Igal Sapir [mailto:i...@getrailo.org] Sent: Thursday, July 31, 2014 11:35 AM To: Tomcat Users List Subject: RE: Programmatically retrieve number of tomcat connections Write a simple ServletFilter On Jul 31, 2014 9:33 AM, Campbell, Lance la...@illinois.edu wrote: Good question. I would like to have a servlet that would return to me the number of tomcat HTTP connections. I know you can do this via a Linux console command. But I would prefer to do it via a servlet. Thanks, Lance Campbell Software Architect Web Services at Public Affairs 217-333-0382 -Original Message- From: Mark Thomas [mailto:ma...@apache.org] Sent: Thursday, July 31, 2014 11:10 AM To: Tomcat Users List Subject: Re: Programmatically retrieve number of tomcat connections On 31/07/2014 17:06, Campbell, Lance wrote: Tomcat 7 Is there a way via a Java servlet to get the number of tomcat connections? Connections from what to what in what state? With or without non-Servlet API calls? Mark - 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 - 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 -- Igal Sapir Railo Core Developer http://getRailo.org/ - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
RE: Programmatically retrieve number of tomcat connections
From: Igal @ getRailo.org [mailto:i...@getrailo.org] Subject: Re: Programmatically retrieve number of tomcat connections 1) you create a class that implements the Filter interface and maintains the count in an AtomicLong object. 2) you increment the AtomicLong before the call to chain.doFilter() and decrement it after that call. This has nothing to do with the number of connections. another way I can think of is to get all the threads in the JVM with Thread.getAllStackTraces(), loop over them, and check their names for example. Which also has little to do with the number of connections, especially when using NIO. You may be able to dig the number of connections out via an internal JMX call. This is, of course, Tomcat specific, but avoids trying to invoke Tomcat's internal classes. - Chuck THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE PROPRIETARY MATERIAL and is thus for use only by the intended recipient. If you received this in error, please contact the sender and delete the e-mail and its attachments from all computers. - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
RE: Programmatically retrieve number of tomcat connections
Isn't Filter.doFilter() called once for each incoming http request? On Jul 31, 2014 10:24 AM, Caldarale, Charles R chuck.caldar...@unisys.com wrote: From: Igal @ getRailo.org [mailto:i...@getrailo.org] Subject: Re: Programmatically retrieve number of tomcat connections 1) you create a class that implements the Filter interface and maintains the count in an AtomicLong object. 2) you increment the AtomicLong before the call to chain.doFilter() and decrement it after that call. This has nothing to do with the number of connections. another way I can think of is to get all the threads in the JVM with Thread.getAllStackTraces(), loop over them, and check their names for example. Which also has little to do with the number of connections, especially when using NIO. You may be able to dig the number of connections out via an internal JMX call. This is, of course, Tomcat specific, but avoids trying to invoke Tomcat's internal classes. - Chuck THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE PROPRIETARY MATERIAL and is thus for use only by the intended recipient. If you received this in error, please contact the sender and delete the e-mail and its attachments from all computers. - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: Programmatically retrieve number of tomcat connections
-BEGIN PGP SIGNED MESSAGE- Hash: SHA256 Chuck, On 7/31/14, 1:22 PM, Caldarale, Charles R wrote: From: Igal @ getRailo.org [mailto:i...@getrailo.org] Subject: Re: Programmatically retrieve number of tomcat connections 1) you create a class that implements the Filter interface and maintains the count in an AtomicLong object. 2) you increment the AtomicLong before the call to chain.doFilter() and decrement it after that call. This has nothing to do with the number of connections. another way I can think of is to get all the threads in the JVM with Thread.getAllStackTraces(), loop over them, and check their names for example. Which also has little to do with the number of connections, especially when using NIO. You may be able to dig the number of connections out via an internal JMX call. This is, of course, Tomcat specific, but avoids trying to invoke Tomcat's internal classes. +1 IMO, this is the right way to do it. You don't have to use a JMX connection, even: you can just query the local JMX server for the bean object and interrogate it. Lance, look at the source code to the JMXProxyServlet and you can see how to fetch JMX beans from the server. Then, just write some code to do the same thing for the bean you're looking for and grab the data you want. Or, you could just use the JMX proxy servlet directly to fetch the data you want. Why do you want this information from /inside/ the application, rather than outside of it? - -chris -BEGIN PGP SIGNATURE- Version: GnuPG v1 Comment: GPGTools - http://gpgtools.org Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQIcBAEBCAAGBQJT2nzeAAoJEBzwKT+lPKRYZqkP/0y/m6XFlb689l64rHzmH9ia pVjtPkoTGTNFNEcYbYEM1yK2n56Ty9kbzP0svhNRJPfsBghvhXOi/qG7IQ6cxTq0 skFQ+ybCXCFuUviaTUdrzYbrB+AkKRT3K9gnjOHdRetlLGCJffmDPVHiUyQekAMF s4jHBaEJ466rrScfQtW8hMEA+S8ra9gRDkYV2h9jjwuXohqAIc6qgnDsUBlzQzgp JceP4PjuaDr1KAONGY+tJ7fLxHwf2GLs0D7urfIRPH9dlxk3pv2O0JzzXpk2pXsX yxm02JSQGX1jk1EbNNqzB8+eUf7coMWseRfbRGuvB2GgB4zWGeq9qFwgsl83FT1k RpSUf6XWrXduVw9FHev5Usus/riqP71lZjZAg1EgM/DJXdXmcfIOElQrOCI0nTra WMuB+p1XSLPf57RffsjkMy4SyqQjcryK4Z6pjYHiezYe//7hCqpMQeFhx4tIRh6g jWSsO0ayGmurmzX0LjteYSR9ru6tFlxqQ+2taGR0ZgdCmiVwfc4CTLj7orgRojJg XsD5K0jnyIXbvXdgdD0qfWs4eJIDBgquRX+A97qUAtoLOqBy/s9hv/OHIYfqlbbW KOxSm2YlJ/TYm+pZOKJlHYh7W1+tErq7C+2AqqD78bytgetCYEHihYmIGRP0HpiP zr2jw9wnMaGJcpUTPwN9 =2Vqm -END PGP SIGNATURE- - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
RE: Programmatically retrieve number of tomcat connections
From: Igal Sapir [mailto:i...@getrailo.org] Subject: RE: Programmatically retrieve number of tomcat connections Isn't Filter.doFilter() called once for each incoming http request? Yes, which is why it has nothing to do with the number of _connections_. - Chuck THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE PROPRIETARY MATERIAL and is thus for use only by the intended recipient. If you received this in error, please contact the sender and delete the e-mail and its attachments from all computers. - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: Programmatically retrieve number of tomcat connections
Caldarale, Charles R wrote: From: Igal Sapir [mailto:i...@getrailo.org] Subject: RE: Programmatically retrieve number of tomcat connections Isn't Filter.doFilter() called once for each incoming http request? Yes, which is why it has nothing to do with the number of _connections_. To elaborate just a little : Presumably when the OP wrote connections, he meant connections, and this was not just sloppy language. In that case, consider keep-alive connections : a browser establishes *one* connection to Tomcat, and then uses that same connection to send 100 HTTP requests (and get 100 HTTP responses) over that same connection. A filter would count 100 requests (assuming that they are all to that same application), but there would still be a single connection. (On the other hand of course, if all the request were directed to another application which does not have the filter, then the filter would count 0 requests, and there would still be 1 connection). Talking about fuzzy language though, review Mark's original response : which connections are we talking about here ? and are we talking about a snapshot, where we want to know how many connections with Tomcat are active at a specific moment in time, or how many connections with Tomcat have been established/closed over a period of time ? Or about something else altogether ? And if one really wanted to count connections at the Tomcat level, I would imagine that the sensible place to do this would be at the Connector level, no ? (all of them) - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: Programmatically retrieve number of tomcat connections
André -- thank you for making this clear. On 7/31/2014 2:27 PM, André Warnier wrote: Caldarale, Charles R wrote: From: Igal Sapir Subject: RE: Programmatically retrieve number of tomcat connections Isn't Filter.doFilter() called once for each incoming http request? Yes, which is why it has nothing to do with the number of _connections_. To elaborate just a little : Presumably when the OP wrote connections, he meant connections, and this was not just sloppy language. In that case, consider keep-alive connections : a browser establishes *one* connection to Tomcat, and then uses that same connection to send 100 HTTP requests (and get 100 HTTP responses) over that same connection. A filter would count 100 requests (assuming that they are all to that same application), but there would still be a single connection. (On the other hand of course, if all the request were directed to another application which does not have the filter, then the filter would count 0 requests, and there would still be 1 connection). Talking about fuzzy language though, review Mark's original response : which connections are we talking about here ? and are we talking about a snapshot, where we want to know how many connections with Tomcat are active at a specific moment in time, or how many connections with Tomcat have been established/closed over a period of time ? Or about something else altogether ? And if one really wanted to count connections at the Tomcat level, I would imagine that the sensible place to do this would be at the Connector level, no ? (all of them) - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org -- Igal Sapir Railo Core Developer http://getRailo.org/ - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
