> On Jun 24, 2024, at 15:36, Eric Robinson <eric.robin...@psmnv.com> wrote: > >> -----Original Message----- >> From: Chuck Caldarale <n82...@gmail.com> >> Sent: Monday, June 24, 2024 1:29 PM >> To: Tomcat Users List <users@tomcat.apache.org> >> Subject: Re: Isolating the Root Cause of "Connection Refused" >> >> >>> On Jun 24, 2024, at 15:19, Eric Robinson <eric.robin...@psmnv.com> wrote: >>> >>> We have a tomcat server that is not that busy. It has 100 tomcat instances >> running, but it handles a few hundred connections per second total, across >> all of >> them. It intermittently rejects connection attempts to listening tomcats. The >> server is running Rocky 8, has 48 cores (about 15-40% utilized), 1T RAM (400G >> free), with NVME storage. 'sar' shows almost 0% iowait. >>> >>> During production: >>> >>> * /proc/sys/net/netfilter/nf_conntrack_count shows anywhere from 100K to >> 250K connections >>> * /proc/sys/net/netfilter/nf_conntrack_max is set to 2M. >>> * netstat -an|wc -l usually shows 90-150K connections >>> >>> Obviously, the TCP stack must be running into some resource limitation, or >> some kind of race condition. I've been working the issue for hours and days, >> without success. How can I determine exactly why the tomcats intermittently >> reject connections? >> >> >> Perhaps some of the Tomcat processes are occasionally running out of file >> descriptors? >> > > Great thought. Wouldn't tomcat log a message somewhere if that were the case?
No - Tomcat would never see the request and would have no knowledge that the OS blocked the connection attempt. - Chuck --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
