The results are looking great so far. Here's what we know:
Before the patch, we had 2 load-balanced tomcats in production for this customer. Due to the driver search bottleneck, we were seeing hundreds of stuck threads during the slowdown periods. To work around this problem, we threw more tomcats at it. With 6 tomcats, the load was spread around enough to keep the bottleneck condition from manifesting badly, and users did not complain as much. We were still seeing dozens of stuck threads, but not hundreds. After the patch, we went back to 2 tomcats. During the same timeframe today, there have been 1 stuck thread on Tomcat A and 6 on Tomcat B. If the numbers hold, this works out to roughly a 10,000% improvement. > -----Original Message----- > From: Eric Robinson <eric.robin...@psmnv.com> > Sent: Friday, May 31, 2024 5:54 AM > To: Tomcat Users List <users@tomcat.apache.org> > Subject: RE: Database Connection Requests Initiated but Not Sent on the Wire > (Some, Not All) > > Mark, > > > -----Original Message----- > > From: Mark Thomas <ma...@apache.org> > > Sent: Thursday, May 30, 2024 9:30 AM > > To: users@tomcat.apache.org > > Subject: Re: Database Connection Requests Initiated but Not Sent on > > the Wire (Some, Not All) > > > > OK. > > > > This is an interim binary patch for 9.0.80 only. > > > > The purpose is to: > > - confirm the proposed change fixes the problem > > - provide you with a workaround in the short term > > > > This is the binary patch: > > > > https://people.apache.org/~markt/dev/classloader-not-found-cache-9.0.8 > > 0- > > v1.zip > > > > Extract the contents into $CATALINA_HOME/lib > > > > You should end up with: > > > > $CATALINA_HOME/lib/org/apache/... > > > > Usual caveats apply. This is not an official release. Use it at your > > own risk. Don't blame either me or the ASF it is results in alien > > invasion, a tax bill, the server catching fire or anything else unexpected > and/or unwanted. > > > > Longer term, I'm not sure this is exactly how I want to fix it in > > Tomcat. I am convinced of the need to cache classes that don't exist > > but exactly where / how to do that and what degree of control the user > > should > have is very much TBD. > > > > I suspect this will be a topic of discussion at Community Over Code at > > Bratislava next week. > > > > I am expecting that any fix won't be in the June release round but > > should be in the July release round. > > > > Let us know how you get on and good luck. > > > > The changes have been applied. We'll know at around 9:30 am EST if they have > had the desired effect. Fingers crossed! > > > > Mark > > > > > > On 30/05/2024 10:16, Mark Thomas wrote: > > > On 29/05/2024 17:03, Eric Robinson wrote: > > > > > > <snip/> > > > > > >> One of the webapps is related to voice reminder messages that go > > >> out to people. The reminders go out sometime after 9 am, which > > >> tracks with the slowdowns. > > > > > > Ack. > > > > > > Something to try while I work on a patch is setting > > > archiveIndexStrategy="bloom" on the resources. > > > > > > You'd configure that in META-INF/context.xml something like this: > > > > > > <Context> > > > <Resources archiveIndexStrategy="bloom" /> </Context> > > > > > > Mark > > > > > > -------------------------------------------------------------------- > > > - 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 > > Disclaimer : This email and any files transmitted with it are confidential and > intended solely for intended recipients. If you are not the named addressee > you > should not disseminate, distribute, copy or alter this email. Any views or > opinions presented in this email are solely those of the author and might not > represent those of Physician Select Management. Warning: Although Physician > Select Management has taken reasonable precautions to ensure no viruses are > present in this email, the company cannot accept responsibility for any loss > or > damage arising from the use of this email or attachments. > B > KKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKK > KKKKCB [ X ܚX KK[XZ[ > > \ \ ][ X ܚX P X ] > \X K ܙ B ܈Y][ۘ[ [X[ K[XZ[ > > \ \ Z[ X ] > \X K ܙ B Disclaimer : This email and any files transmitted with it are confidential and intended solely for intended recipients. If you are not the named addressee you should not disseminate, distribute, copy or alter this email. Any views or opinions presented in this email are solely those of the author and might not represent those of Physician Select Management. Warning: Although Physician Select Management has taken reasonable precautions to ensure no viruses are present in this email, the company cannot accept responsibility for any loss or damage arising from the use of this email or attachments.
