Borland has also a light weight server side product to profile web apps. Can t remember the name. Bruno Georges
Glencore International AG Tel. +41 41 709 3204 Fax +41 41 709 3000 ----- Original Message ----- From: Peter Lin [EMAIL PROTECTED] Sent: 16.12.2005 06:40 To: Tomcat Users List <users@tomcat.apache.org> Subject: Re: Performance degradation under load I hear YourKit is good. I've mainly used OptimizeIt the last 4 years and it works well for me. something odd is definitely happening. at this point, it sounds you've exhausted all the obvious and not so obvious options, so it's probably most fruitful to profile it. peter On 12/16/05, Marc Richards <[EMAIL PROTECTED]> wrote: > > No, the firewall is in front of the load balancers and > the servers are separated from the network by the dmz. > At some point there will be a reverse proxy in there > somewhere (they tell me - I'm not a network engineer), > but at the moment it's not open to the internet so I > just have it directly opened to the db. > > Thanks for the chat anyway. I have not used a > profiler for a Win32 web server before. Do you have > any recommendation? > > -marc > > --- Peter Lin <[EMAIL PROTECTED]> wrote: > > > sounds like you have a big big mainframe, so I also > > doubt the database > > server is an issue. Is there any firewall between > > tomcat and the database > > server? it could be the firewall is limiting the > > number of connections and > > therefore forcing the db connection pool to wait > > longer than it should to > > create a new connection. > > > > beyond that, about the only way would be to start > > tomcat using a profiler > > and see exactly what is blocking. > > > > peter > > > > > > On 12/15/05, Marc Richards <[EMAIL PROTECTED]> wrote: > > > > > > No, the db is actually our world-wide enterprise > > > server. It's got plenty of capacity for handling > > many > > > hundreds of thousands of daily transactions. When > > I'm > > > pounding the web app I literally can not even see > > my > > > activity on the machine and the disk arms are all > > > calm. It's made for tougher stuff than I'll ever > > be > > > able to throw at it (due to JDE client programs > > being > > > so chatty, it's necessary to have a very powerful > > db > > > when you run OneWorld). > > > > > > It's kind of hard to track how many open db > > > connections there are from the db end because > > normally > > > there are many thousands to begin with and the > > number > > > fluctuates by leaps and bounds just as a course of > > > doing regular business. > > > > > > I'm not sure that my sessions are of too much > > concern > > > at the moment either because when I check the > > server > > > boxes I'm seeing that Tomcat is only using between > > 200 > > > and 400 mg of RAM and there is 4gb available. I > > don't > > > have a short session kill time (I think it's two > > hours > > > at the moment), but I am failing them out to disk > > > every few minutes, so inactive sessions should be > > > staying out of physical memory. And by the low > > memory > > > consumption of Tomcat under load, I'd say that > > part is > > > probably working ok (and also because I can see > > all of > > > the db records in the session table). > > > > > > I haven't gotten any complaints from the db on the > > > session table itself, but that doesn't mean that > > there > > > isn't collusion because there could be some > > locking > > > issues taking place that would cause session > > backups > > > and restores to take on some latency. The db > > won't > > > complain about a locking issue and I haven't been > > able > > > to find any myself, but due to the fact that each > > > connection appears to open, read/write and then > > > abandon, locks would come and go so quickly that I > > > probably wouldn't be able to see them anyway. > > > > > > I did notice that the db performance optimizer was > > > spending some extra time analyzing the sessions > > table, > > > but I think that's because it regularly gets a > > bunch > > > of records pumped to it and then it clears out as > > > sessions become invalidated. It's really quite > > > under-used compared to most of the JDE tables on > > the > > > system. > > > > > > I was concerned about the maxThreads for a time > > (and > > > actually did have a problem because Apache's was > > set > > > higher and puking when it over-ran). But I got > > tired > > > of tweaking for this and just set it at 5000 to > > see > > > what would happen. I think the default is only > > 50, so > > > I thought 10x would represent a 'big' site. Am I > > > wrong? It didn't change a thing by setting it > > that > > > high. How do you check the queue depth? I'm not > > sure > > > I'm familiar with that one... > > > > > > - > > > > > __________________________________________________ > Do You Yahoo!? > Tired of spam? Yahoo! Mail has the best spam protection around > http://mail.yahoo.com > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > > LEGAL DISCLAIMER. The contents of this e-mail and any attachments are strictly confidential and they may not be used or disclosed by someone who is not a named recipient. If you have received this email in error please notify the sender by replying to this email inserting the word "misdirected" as the message and delete this e-mail from your system.
