[Bug 134274] Re: TCP_DEFER_ACCEPT causes random HTTP connection failures in load-balanced web-server farms
Upstream marked this as fixed in 2.2.28, which is from the Ubuntu precise timeframe. Trusty already ships 2.4.7, so marking this fix released. ** Changed in: apache2 (Ubuntu) Status: Confirmed => Fix Released -- You received this bug notification because you are a member of Ubuntu Server, which is subscribed to apache2 in Ubuntu. https://bugs.launchpad.net/bugs/134274 Title: TCP_DEFER_ACCEPT causes random HTTP connection failures in load- balanced web-server farms To manage notifications about this bug go to: https://bugs.launchpad.net/apache2/+bug/134274/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
[Bug 134274] Re: TCP_DEFER_ACCEPT causes random HTTP connection failures in load-balanced web-server farms
related upstream bug: https://issues.apache.org/bugzilla/show_bug.cgi?id=41270 -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to apache2 in Ubuntu. https://bugs.launchpad.net/bugs/134274 Title: TCP_DEFER_ACCEPT causes random HTTP connection failures in load- balanced web-server farms To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/apache2/+bug/134274/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
[Bug 134274] Re: TCP_DEFER_ACCEPT causes random HTTP connection failures in load-balanced web-server farms
This exact problem causes havoc if you have many slow clients on slow networks (gprs). We actually had this problem, and to confirm #8. its *really* hard to catch. We actually had a 80% unsuccessfull connection attemps. I cannot believe Apache ships with TCP_DEFER_ACCEPT on 1 sec, or even enabled at all. I don't see the possible gain. ref: varnish had it enabled for a while but they disabled it too [1] Can ubuntu change the default config to include: AcceptFilter http none AcceptFilter https none [1] https://github.com/Movile/varnish/commit/687bacb3152ebc8b00b8dd737ef1dedb12bd4ee2 -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to apache2 in Ubuntu. https://bugs.launchpad.net/bugs/134274 Title: TCP_DEFER_ACCEPT causes random HTTP connection failures in load- balanced web-server farms To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/apache2/+bug/134274/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
[Bug 134274] Re: TCP_DEFER_ACCEPT causes random HTTP connection failures in load-balanced web-server farms
Unfortunately upstream cannot agree on what precisely the standards require in relation to TCP_DEFER_ACCEPT, thus this issue slips through the cracks and doesn't affect enough installations to create any real drive. As can be seem from my investigations it is an obscure bug which is very hard to catch and probably goes unseen in most circumstances. My preferred solution would be a prominent addition to the Debian/Ubuntu READMEs for apache with a reference to this bug with advice to use AcceptFilter http none when operating in a load-balancing configuration. -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to apache2 in Ubuntu. https://bugs.launchpad.net/bugs/134274 Title: TCP_DEFER_ACCEPT causes random HTTP connection failures in load- balanced web-server farms To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/apache2/+bug/134274/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
[Bug 134274] Re: TCP_DEFER_ACCEPT causes random HTTP connection failures in load-balanced web-server farms
This is a pretty old bug, and doesn't seem to have been linked to any upstream issue, even though it is likely just that. Has anyone verified that the behavior persists on a more recent release of Ubuntu? -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to apache2 in Ubuntu. https://bugs.launchpad.net/bugs/134274 Title: TCP_DEFER_ACCEPT causes random HTTP connection failures in load- balanced web-server farms To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/apache2/+bug/134274/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
[Bug 134274] Re: TCP_DEFER_ACCEPT causes random HTTP connection failures in load-balanced web-server farms
When TCP_DEFER_ACCEPT is enabled on the listening socket: - HTTP-Keep-Alive requests get a boost; - non-HTTP-Keep-Alive requests are delayed after a while. The problem happens with high concurrencies only. This has been tested with various HTTP servers and is a consistant behavior on Linux Ubuntu 8.1+. The higher the value for TCP_DEFER_ACCEPT, the faster HTTP servers get into trouble (when they receive ab connections without -k): ab -t 100 -c900 http://a.b.c.d/100.html(a 100-byte file) Anyone having a clue why this is happening? (HTTP Keep-Alives being a persistant TCP connection, it is strange to see TCP_DEFER_ACCEPT giving them a boost) (inversely, non-HTTP Keep-Alives being new TCP connections, it is strange to see TCP_DEFER_ACCEPT delaying them) Thanks for any pointer. ** Changed in: apache2 (Ubuntu) Status: Triaged = Invalid ** Converted to question: https://answers.launchpad.net/ubuntu/+source/apache2/+question/99261 -- TCP_DEFER_ACCEPT causes random HTTP connection failures in load-balanced web-server farms https://bugs.launchpad.net/bugs/134274 You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to apache2 in ubuntu. -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
[Bug 134274] Re: TCP_DEFER_ACCEPT causes random HTTP connection failures in load-balanced web-server farms
Please do not change the status of a confirmed/triaged bug that describes a known issue that is as yet unresolved. ** Changed in: apache2 (Ubuntu) Status: Invalid = Triaged -- TCP_DEFER_ACCEPT causes random HTTP connection failures in load-balanced web-server farms https://bugs.launchpad.net/bugs/134274 You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to apache2 in ubuntu. -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
