I open 8 IE on a remote computer, basically once a JSP is called, the browser is just waiting the process to be done.
-----Original Message----- From: David Smith [mailto:[EMAIL PROTECTED] Sent: 4 mai 2008 23:00 To: Tomcat Users List Subject: Re: Tomcat problem on a multiple CPU system Can you describe how you open the 8 browser windows and what browser you are using? I ask because those 8 browser windows may be coming from one process and using at most 2 connections, hence the slower processing. Firefox normally only has one process no matter how you open the new windows. IE can be 8 separate processes if you launch each separately from Explorer (ie the Start button or desktop shortcut) and not use the new window menu option or ctrl-n. --David Gilbert, Antoine wrote: > Well, each process is a image rendering process. > > But my point is, if I launch 8 threads directly in a JVM outside of > tomcat, it run faster and use 100% of the 8 CPU... > > If I make a Servlet (or a JSP) who will start a process each time I call > it (I call it 8 times). > > So, the big question is, why It's fast directly on the JVM and it's slow > on Tomcat ? Why with Tomcat It's not possible to use 100% of all the 8 > CPU ? There is no data transfer between client and server, in both case > the images are rendered on the disk. > > I just made this rendering test to expose the fact that I'm unable to > make my tomcat use efficiently all my CPU. > > So the big question, why these 8 processes run betters than these 8 > process within Tomcat ? > > > > -----Original Message----- > From: Alan Chaney [mailto:[EMAIL PROTECTED] > Sent: 4 mai 2008 17:33 > To: Tomcat Users List > Subject: Re: Tomcat problem on a multiple CPU system > > Hi Antoine > > The thing to remember is that this is a system which has (at least) four > > main parts: > > 1. Tomcat > 2. The operating system > 3. A network connection > 4. Your application > > (and potentially) > > 5. A database (but you didn't mention that) > > Here are some questions. > > 1. How do you make the connection to the servlet. Does the browser run > on the same machine as the application? > > 2. Does you application create network traffic? If so, how many bytes > are transferred to the browser? Each servlet thread will have to wait > until the application has transferred all the data out. > > 3. What kind of disk activity does your application generate? Is it > different when the app is running from the servlet? > > Probably somewhere your servlet threads are sleeping waiting for a > resource. You could do a thread dump to see what is happening (I don't > use Windows so I can't remember how you do that with the Win setup) > > In the end, you'll need to profile the system to work out where the > bottlenecks are. You'll need to use network analysers and probably Java > profilers to track down what's happening such as when packets are > received, when the replies are generated and maybe profile what your > app. is doing. > > HTH > > Alan Chaney > > > > > Gilbert, Antoine wrote: > >> Hi >> >> >> >> I have a 2x quad core (8 cpu units) server. >> >> >> >> If I start a java program and this one is launching (at the same time) >> > 8 > >> thread doing some CPU intensive jobs, all the CPU are used at 100%, >> > and > >> that's what I'm expecting.. >> >> >> >> But, if I am using tomcat, and I call a servlet 8 times to process >> > these > >> 8 jobs, it take longer to execute these same 8 jobs and all the CPU >> > are > >> not used at 100%, it's more like 30%... >> >> >> >> Any idea about this problem or behavior ? I'm using Tomcat 5.5.17, >> windows, JDK 1.6 >> >> >> >> Antoine >> >> >> >> !DSPAM:481e1bf27941527717022! >> >> > > --------------------------------------------------------------------- > To start a new topic, e-mail: users@tomcat.apache.org > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > > > > --------------------------------------------------------------------- > To start a new topic, e-mail: users@tomcat.apache.org > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > > -- David Smith Network Operations Supervisor Department of Entomology Cornell University 2132 Comstock Hall Ithaca, NY 14853 Phone: (607) 255-9571 Fax: (607) 255-0940 --------------------------------------------------------------------- To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] --------------------------------------------------------------------- To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
