What sort of transaction isolation level requirements does your application have?
If users are prevented from accessing the functionality of the system when a large query is being run then I would recommend checking whether the database is locking the tables. cinlung wrote: > > Dear Leon > > Let me answer your question by the number of the questions: > 1. My threadpool settings: are you talking about the java threadpool or > the > tomcat server setting for the thread pool. If this is tomcat, I am sorry I > think I set it to standard from installation. I did not change any tomcat > standard settings except for the -xmx and -xms stuff. As for java, the DB > thread pool is set for 200 connections at once. > > What I meant by slows down is that user clicks on a simple form view > function that usually takes less dan a blink of an eye to open, now the > application just not responding. The browser just keep loading and the > load > animation for IE keeps spinning, but does not return the appropriate > response page and sometimes it just died (blank). When I check the tomcat > logs nothing went wrong. > > This happens if a user run one of the heavy duty app and someone else run > another app (even simple ones). Regarding multiple tomcat machine.... I am > trying to avoid it because I would have to rewrite the entire software or > get an QOS machine to disperse the weight. > > 2. For number 2, I did the warning for user to wait and not to close the > browser before it is finished. But, a lot of them just don't even bother > to > read the warning and keep closing it. I was wondering if there is an API > for > monitoring dead users out there. Or I can always create a new API to > monitor > user activities by planting an applet on the user site that will keep > pinging to the server and if the ping died, that means the user closed the > browser. Is this wise? > > Or I can try to see The java Concurency thing that you mentioned below. > > Thank you for your advice and sorry for my bad English. > > > -----Original Message----- > From: Leon Rosenberg [mailto:rosenberg.l...@googlemail.com] > Sent: Thursday, April 08, 2010 5:31 PM > To: Tomcat Users List > Subject: Re: Tomcat scalability setting - need help please > > Hello Rendra, > > comments inline. > > On Thu, Apr 8, 2010 at 11:00 AM, Cin Lung <cinl...@gmail.com> wrote: >> Dear All Dev >> >> Sorry if repost, I got an error from the mailing list server. >> Can anyone help me with my problem? I have two biggest problems as >> follow: >> >> 1. Multi Connection Problem: >> I have a web application that service to multiple users. Everytime the >> users accessing the server reach 100 users at the same time, the >> tomcat would slows down. I tried to set -xmx1024 and -xms1024, but it >> did not have any impact at all. >> I tried to set the memory cache to 2048 and above, but the tomcat >> won't start. > > What are your threadpool settings? What exactly is 'slows down' If it > stops > responding you are obviously running out of threads. If it just gets > slower, > you should consider measuring the load on your machine and webapp. > Maybe you should consider scaling to multiple tomcats/machines. > >> Is there any way to improve tomcat's performance. Will there be any >> use of Java NIO Framework in tomcat? I mean apache has Mina, why not >> combine with tomcat? > > There are a lot of ways, but first you should identify your problem. > >> >> 2. User cancellation problem >> Another thing that really bug me is that user would click on a web >> application that perform a very extensive task. The user was not >> patient and just close the browser accessing the app. This did not >> make that particular job stop. In fact the job is still running until >> finish and then it got no place to return the result since the user >> closed the browser. As the result, my server is working really hard >> and takes up all the resources available, and causes other users to lag. >> >> Is there any way to make that particular user task/thread stop working? > > The common way to handle this is to inform user that the task is going to > last a bit more. To achieve this, the original request starts a background > job which executes the heavy task. The original request then sends the > user > to a wait page, which explains that he/she has to wait for the execution. > The wait page reloads itself all 1-2 seconds checking whether the > background > job has finished. If this happens, the wait page sends the user to the > result page, where he can examine the result of the background task. > There are a lot of classes like Executor, Future etc. which can help you > in > synchronization of background jobs. Java Concurrency in Practice is a good > particular start. > > regards > Leon > > > > > > > > >> >> Thank you in advance >> Rendra >> >> >> --------------------------------------------------------------------- >> 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 > > > -- View this message in context: http://old.nabble.com/Tomcat-scalability-setting---need-help-please-tp28175969p28211399.html Sent from the Tomcat - User mailing list archive at Nabble.com. --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
