Thanks for replying I think you are on the right track i must not be doing something right here. You certainly got me confused and that can only be a step in the right direction. I have my session-timeout set to 15. My load is being generated from massive usage i get a million unique hits a month and have a lot of customers simultaneously logged in at once. Tomcat starts out with 128 megs and baloons up pretty quickly to 300 megs. It often exceeds that, there also seems to be a huge thread count.
I do not use cookies and I do not call "session.setMaxInactiveInterval()" or "session.invalidate()" or response.encodeURL(). In fact I am completely ignorant about these calls. I assume my sessions are closed automatically by tomcat when there is no usage from that client for 15 minutes. So can I assume session.invalidate() kills a session. How and in what situation would I use this method? What does setMaxInactiveInterval do and how is that applied? And same questions on response.encodeURL()? So you are saying that possible it is not only creating a new session per new user but per page each user accesses? If so please teach me how to fix my problems with my coding. -ryan On Mon, 2 Dec 2002, Julius Davies wrote: > > Developer, > > Hello. I use Tomcat 4.1.12 standalone. I was just thinking about what you were >saying, especially "[...] I would think the memory stamp would correspondingly shrink >when all these sessions are closed and it doesn't". > > I noticed this section in the default "web.xml": > > <!-- ==================== Default Session Configuration ================= --> > <!-- You can set the default session timeout (in minutes) for all newly --> > <!-- created sessions by modifying the value below. --> > > <session-config> > <session-timeout>30</session-timeout> > </session-config> > > So, by default on my machine sessions will stay around for 30 minutes, unless either >"session.setMaxInactiveInterval()" or "session.invalidate()" was called. I haven't >changed this file since I installed Tomcat, and so I'm assuming you have the same >file. > > Are you calling either of those methods - invalidate or setMaxInactiveInterval? Or >when you say "these sessions are closed", do you mean they time out after 30 minutes? > > Secondly, what are you doing to generate all this (server-crashing!) load? >Obviously you're not going to call "session.invalidate()" on the same page that you >created the session. That would be pointless... so here comes an interesting >possibility: suppose a significant portion of your load didn't support cookies? Or, >if you were using URL rewriting for the sessions, suppose you forgot to use >"response.encodeURL()"? In both cases the result is the same: > > Sessions are being created for a client, but the client won't remember his special >"session id". This means a new session is created for this client with every request >he makes! > > So, I have three questions I need to know: > > 1.) What kind of load is Tomcat experiencing on your machine, and where is this >load coming from? > > 2.) Does your load support cookies? Is the "session id" being remembered by the >client? > > 3.) How are you closing your sessions? > > Suppose each of your sessions weighed in at 512 bytes. If your load, at, let's >pretend 10/hits second, didn't support cookies, you're going to need ~15mb to hold on >to 30 minutes of sessions before they start expiring. This is because each hit is >going to create a new session. > > Tomcat User please correct any mistakes I may have made here! > > > Julius Davies, Programmer, CUCBC > Email: [EMAIL PROTECTED], Ph: 604.730.6385 > > > > > -----Original Message----- > > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] > > Sent: Monday, December 02, 2002 1:24 PM > > To: Tomcat Users List > > Subject: Re: Memory/Performance > > > > > > Thanks for your comments. Well all my jspcode is definitely > > session happy > > and I am creating several > > objects per session. The objects I am creating consist of mostly > > string, int and floats, probably up to like 20 of each. > > Although i create > > a large application pool of jdbc > > connections I am fairly positive that this is not the problem > > because I > > use this pooling model in several applications that don't > > seem to have a > > problem. I realize that every time a session is created all > > these objects > > must be allocated, and that should cause the memory blob to > > keep growing > > as the session count increase but I would think the memory stamp would > > correspondingly shrink when all these sessions are closed and it > > doesn't. I am basing this on tomcats crashing or slow behavior > > in conjunction with monitoring the processes and memory > > usage. What other > > information can I share that would help? Like I said I don't > > know if this > > is tomcat or me or a bit a both so I am jsut throwing out > > what seems to be > > going on and looking for insight? > > > > > > > > > > On Mon, 2 Dec 2002, Michael Nicholson wrote: > > > > > I suppose it depends on what you're doing, which, > > unfortunately, I don't > > > know. > > > > > > If you're overly filling your session w/ objects, or if you > > have a session > > > scoped bean that is spiraling out of control or something, > > that might lead > > > to the problem, or if you create/leave open jdbc > > connections or stuff like > > > that. I'm running tomcat 4.03 on a much less beefy system, > > and I don't ever > > > notice any memory issues, now that I make sure I close and null my > > > connections and such. > > > > > > More info on what's happening might help, though.. > > > > > > > > > ----- Original Message ----- > > > From: <[EMAIL PROTECTED]> > > > To: "Tomcat Users List" <[EMAIL PROTECTED]> > > > Sent: Monday, December 02, 2002 3:51 PM > > > Subject: Memory/Performance > > > > > > > > > > I find that tomcat's memory stamp grows continually until > > eventually there > > > > are out of memory errors or it just bogs down. I am > > running on jdk1.4_1, > > > > tomcat 4.1.12, apache 1.27, mod_jk on the linux 2.2 > > kernel. The box I am > > > > operating on has 1gig of memory and has dual gigahertz > > processors. I > > > > believe that tomcat has some serious memory leaks and/or > > I am not writing > > > > my jsppages properly. So i would like to ask two questions: > > > > > > > > > > > > 1)Assuming tomcat has memory issues what can I do to control them? > > > > > > > > > > > > > > > > > > > > 2)What techniques would you suggest to write jsppages > > that help keep > > > > memory consumption down? Are there ways to write > > jsppages that makes them > > > > more "garbage collection friendly"? > > > > > > > > please comment.... > > > > > > > > > > > > -- > > > > To unsubscribe, e-mail: > > > <mailto:[EMAIL PROTECTED]> > > > > For additional commands, e-mail: > > > <mailto:[EMAIL PROTECTED]> > > > > > > > > > > > > > > > > > -- > > > To unsubscribe, e-mail: > <mailto:[EMAIL PROTECTED]> > > For additional commands, e-mail: <mailto:[EMAIL PROTECTED]> > > > > > > > -- > To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> > For additional commands, e-mail: <mailto:[EMAIL PROTECTED]> > > -- To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> For additional commands, e-mail: <mailto:[EMAIL PROTECTED]>
