I am gleaning from your comments that MaxThreads is the only thing to tweak. Yes I do really have a connection issue. I have millions and millions of connection requests on a very small pool of servers. The app has been tuned constantly over years. I am either bound to buy more servers or tweak tomcat to get more throughput. In reality, I probably need to do both.
On a large pageview day, we will overflow the 750 MaxThreads. This is noticed by the MaxThreads limit being exceeded error message. We have tweaked all pieces of the tomcat config. I was hoping a post here could get more explanation of the parameters. We have our experience to fall back on, but I was hoping for more. If MaxThreads is the main thing to tweak, we will continue doing so. There is a limit to this though. You should create the funnel for customer requests (webserver limits, mod_jk limits, and tomcat limits). Exploding MaxThreads to a large number just to be large does not seem to fit with having an acceptCount value or the funnel that should be created. Thanks, J On 2/16/07, Andrew Miehs <[EMAIL PROTECTED]> wrote:
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Dear J, The focus should be on your application, and configuring everything thing around that. If you REALLY have an out of connection problem, increase Max Threads to 10000, but I don't think that will really help you. The problem is usually that each individual request takes tooo long, which again, points back to your application - There isn't that much to tweak in tomcat. Once you have configured your application, then you can start looking at the kernel - but these only bring small % improvements. Without more information - ie: current number of threads being used, it is very hard to answer your question. Cheers Andrew On 16/02/2007, at 4:43 AM, j r wrote: > The focus should be on the tomcat tweaking. We get errors in the > tomcat > error logs that say tomcat has reached its connection limits. I > never said > that it was serving slow. It hits connection limits which means > that the > app will not serve any more traffic until connections clear. > > If a box definitely has more capacity (dual core, dual procs), then > my best > guess is that tomcat is not tuned perfectly to allow the max amount of > connections in. We have raised MaxThreads in the past to allow more > connections in. This works, but surely other knobs are important > to be > tweaked. > > I am looking for good definitions and/or best practices on which > knobs to > tweak to allow the max connections in before exhausting the jvm native > memory allocation or cpu on the box. > > > > Thanks, > J > > On 2/15/07, Andrew Miehs <[EMAIL PROTECTED]> wrote: >> >> -----BEGIN PGP SIGNED MESSAGE----- >> Hash: SHA1 >> >> Dear J' >> >> What do you mean you are hitting connection limits?! Are you getting >> errors? What are you seeing that makes you think that is slow? >> Is there a database involved in this application? >> >> I assume you are running linux on your server, with a 2.6 kernel. >> >> run the following commands while your box >> >> 1) ps auxH >> 2) ps auxH |grep -c java >> 3) vmstat 5 5 >> 4) iostat 5 3 >> >> Then we will have a bit of an idea what is going on. >> >> Andrew >> >> >> >> >> On 15/02/2007, at 9:36 PM, j r wrote: >> >> > The reason it is hitting its limits is easy: traffic. We easily >> > get enough >> > website traffic to overflow the connection limits unless I have >> > many boxes >> > available to serve. I know these can be configured to handle more >> > connections. I know that we should be able to do this in the >> tomcat >> > server. That is why I need those tweaking parameters defined. >> > >> > >> > >> > Thanks, >> > j >> > >> > On 2/15/07, Leon Rosenberg <[EMAIL PROTECTED]> wrote: >> >> >> >> First you should investigate why tomcat is hitting its limits. >> >> Why do you think it does? Which resource is the limit? >> >> Do you have/use any monitoring software? moskito? lambdaprobe? >> >> tomcat-manager? >> >> >> >> regards >> >> Leon >> >> >> >> On 2/15/07, j r <[EMAIL PROTECTED]> wrote: >> >> > I have searched for exact documentation on this, and I always >> find >> >> > conflicting info. Therefore I am reaching out to this list. I >> >> have the >> >> > following info and questions: >> >> > >> >> > - we are running tomcat 5.5.20 >> >> > - we have the following configs in server.xml: >> >> > <Connector port="8009" >> >> > enableLookups="false" redirectPort="8443" >> debug="0" >> >> > maxThreads="750" minSpareThreads="100" >> >> maxSpareThreads="250" >> >> > acceptCount="100" connectionTimeout="5000" >> >> > tomcatAuthentication=" >> >> > false" >> >> > >> >> > - we have extra capacity (mem, cpu, etc.) on the servers, yet >> >> tomcat is >> >> > hitting connection limits >> >> > - we feel that tomcat can serve more, so what do we tune to make >> >> it do >> >> so? >> >> > - maxThreads? >> >> > - minSpareThreads? >> >> > - maxSpareThreads? >> >> > - acceptCount? >> >> > >> >> > >> >> > Honestly, I would rather love an exact definition of what each >> >> of those >> >> > would do to the tomcat server if tweaked. Knowing that would be >> >> nirvana >> >> for >> >> > tuning. >> >> > >> >> > >> >> > >> >> > -j >> >> > >> >> >> >> >> --------------------------------------------------------------------- >> >> To start a new topic, e-mail: users@tomcat.apache.org >> >> To unsubscribe, e-mail: [EMAIL PROTECTED] >> >> For additional commands, e-mail: [EMAIL PROTECTED] >> >> >> >> >> >> -----BEGIN PGP SIGNATURE----- >> Version: GnuPG v1.4.1 (Darwin) >> >> iD8DBQFF1NaFW126qUNSzvURAuxZAJ4ugkLObXKHJZsSIfX3SWzZzv5vlQCdHXeV >> jSPVOQqZXoxvlQc7Q94vMlA= >> =YSSz >> -----END PGP SIGNATURE----- >> >> --------------------------------------------------------------------- >> To start a new topic, e-mail: users@tomcat.apache.org >> To unsubscribe, e-mail: [EMAIL PROTECTED] >> For additional commands, e-mail: [EMAIL PROTECTED] >> >> -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (Darwin) iD8DBQFF1XNhW126qUNSzvURAtjIAJsHhDX6gXQFPi9UFnFgCPHqB0yGCgCeM7mg e41/HBE3bGRaol1JAJh81ds= =5ZBO -----END PGP SIGNATURE----- --------------------------------------------------------------------- To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
