Re: Extreme load with local password db lookups
Jeremy Chadwick wrote: On Fri, Dec 07, 2007 at 08:44:37AM +0100, Patrick van Iersel wrote: From: Eugene Grosbein [EMAIL PROTECTED] See http://www.freebsd.org/cgi/query-pr.cgi?pr=75855 It seems the regression from RELENG_4 is still here. There are so many regressions in performance that I still prefer to invest time to patch bsd.ports.mk to support 4.x (and have a success, I use fresh ports with 4.x these days) then upgrade my UP boxes to 6.x and suffer from loss of performaince. For what it's worth, Eugene's suggestion of changing nsswitch.conf actually helps. It was mentioned in the PR above as well. It's still a workaround but it works good enough for me now. I stand corrected. :-) The PR referenced by Eugene is dead on. The priority on that PR should really be changed to medium or high, because the impact is major. I'm sure large hosting/shell providers are being bitten by this. My nsswitch.conf looks like the following. Do you get the same benefit (faster lookups) by commenting out the _compat methods, or only if you change group and passwd to 'files'? Doug group: compat #group_compat: nis hosts: files dns networks: files passwd: compat #passwd_compat: nis shells: files services: compat #services_compat: nis protocols: files rpc: files -- This .signature sanitized for your protection ___ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Extreme load with local password db lookups
From: Eugene Grosbein [EMAIL PROTECTED] Date: Fri, 7 Dec 2007 14:48:47 +0700 To: Patrick van Iersel [EMAIL PROTECTED] Cc: freebsd-stable@FreeBSD.org Subject: Re: Extreme load with local password db lookups On Fri, Dec 07, 2007 at 08:44:37AM +0100, Patrick van Iersel wrote: See http://www.freebsd.org/cgi/query-pr.cgi?pr=75855 It seems the regression from RELENG_4 is still here. There are so many regressions in performance that I still prefer to invest time to patch bsd.ports.mk to support 4.x (and have a success, I use fresh ports with 4.x these days) then upgrade my UP boxes to 6.x and suffer from loss of performaince. For what it's worth, Eugene's suggestion of changing nsswitch.conf actually helps. It was mentioned in the PR above as well. It's still a workaround but it works good enough for me now. It would be nice if you make a followup to the PR for the record with a notice about your problem and mention 6.3-PRERELEASE there. Done :) Patrick. ___ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Extreme load with local password db lookups
I would like to point out that in FreeBSD 7.x there is a daemon called nscd. I believe it was created exactly for this purpose (speeding up name lookups by caching them). Is it true that 4.x has nearly O(n) lookup speed while later versions has O(n^2) method? Why 4.x does not need caching daemon to be quick? Eugene Grosbein ___ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Extreme load with local password db lookups
On Friday 07 December 2007, Jeremy Chadwick wrote: On Fri, Dec 07, 2007 at 08:44:37AM +0100, Patrick van Iersel wrote: From: Eugene Grosbein [EMAIL PROTECTED] See http://www.freebsd.org/cgi/query-pr.cgi?pr=75855 It seems the regression from RELENG_4 is still here. There are so many regressions in performance that I still prefer to invest time to patch bsd.ports.mk to support 4.x (and have a success, I use fresh ports with 4.x these days) then upgrade my UP boxes to 6.x and suffer from loss of performaince. For what it's worth, Eugene's suggestion of changing nsswitch.conf actually helps. It was mentioned in the PR above as well. It's still a workaround but it works good enough for me now. I stand corrected. :-) The PR referenced by Eugene is dead on. The priority on that PR should really be changed to medium or high, because the impact is major. I'm sure large hosting/shell providers are being bitten by this. I would like to point out that in FreeBSD 7.x there is a daemon called nscd. I believe it was created exactly for this purpose (speeding up name lookups by caching them). - Pieter de Goeje ___ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Extreme load with local password db lookups
On Friday 07 December 2007, Eugene Grosbein wrote: I would like to point out that in FreeBSD 7.x there is a daemon called nscd. I believe it was created exactly for this purpose (speeding up name lookups by caching them). Is it true that 4.x has nearly O(n) lookup speed while later versions has O(n^2) method? Why 4.x does not need caching daemon to be quick? I don't really know but judging from the others posts the files lookup method is still O(n) thus no change there. The compat method could be slow because of a number of reasons, one of them is bad complexity. One would have to look at the code to find out... ___ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to [EMAIL PROTECTED]
Extreme load with local password db lookups
Hi, Here's the situation. We have an web/ftp server with around 74000 users defined in the local unix password database. On 4.9-stable which it is running now, there is no noticable load when lookups are done (logins via ftp, ~user lookups from apache etc.). We want to migrate this system to 6-stable. However on 6-STABLE (FreeBSD 6.3-PRERELEASE #0: Wed Dec 5 13:35:05 CET 2007) these same lookups cause very high load and things slow down to a crawl. Does anybody have an idea what causes this behavior? Thanx in advance for any insights. Best regards, Patrick. ___ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Extreme load with local password db lookups
On Thu, Dec 06, 2007 at 11:37:50AM +0100, Patrick van Iersel wrote: Here's the situation. We have an web/ftp server with around 74000 users defined in the local unix password database. On 4.9-stable which it is running now, there is no noticable load when lookups are done (logins via ftp, ~user lookups from apache etc.). We want to migrate this system to 6-stable. However on 6-STABLE (FreeBSD 6.3-PRERELEASE #0: Wed Dec 5 13:35:05 CET 2007) these same lookups cause very high load and things slow down to a crawl. Does anybody have an idea what causes this behavior? Thanx in advance for any insights. Take a look to your /etc/nsswitch.conf. If you do not use NIS, try to change lines for 'group' and 'passwd' to look like this: group: files passwd: files Eugene Grosbein ___ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Extreme load with local password db lookups
On Thu, Dec 06, 2007 at 06:22:07PM +0700, Eugene Grosbein wrote: On Thu, Dec 06, 2007 at 11:37:50AM +0100, Patrick van Iersel wrote: Here's the situation. We have an web/ftp server with around 74000 users defined in the local unix password database. On 4.9-stable which it is running now, there is no noticable load when lookups are done (logins via ftp, ~user lookups from apache etc.). We want to migrate this system to 6-stable. However on 6-STABLE (FreeBSD 6.3-PRERELEASE #0: Wed Dec 5 13:35:05 CET 2007) these same lookups cause very high load and things slow down to a crawl. Does anybody have an idea what causes this behavior? Thanx in advance for any insights. Take a look to your /etc/nsswitch.conf. If you do not use NIS, try to change lines for 'group' and 'passwd' to look like this: group: files passwd: files The default value is compat on both RELENG_6 and RELENG_7. I don't think switching to files will fix his problem (I'll be very surprised if it does). -- | Jeremy Chadwickjdc at parodius.com | | Parodius Networking http://www.parodius.com/ | | UNIX Systems Administrator Mountain View, CA, USA | | Making life hard for others since 1977. PGP: 4BD6C0CB | ___ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Extreme load with local password db lookups
Patrick van Iersel wrote: However on 6-STABLE (FreeBSD 6.3-PRERELEASE #0: Wed Dec 5 13:35:05 CET 2007) these same lookups cause very high load and things slow down to a crawl. Hi, How do you know it's the passwd lookups that cause the problems? (I'm not saying they're not...) signature.asc Description: OpenPGP digital signature
Re: Extreme load with local password db lookups
A common way to debug is to isolate the affected systemcalls, by using tools like ktrace or strace. Strace can also record a timestamp, you can see how long it takes to complete a specific systemcall # strace -r -f serverproc Do a single login and then examine the results. happy debugging. regards, Dennis Jeremy Chadwick schrieb: On Thu, Dec 06, 2007 at 06:22:07PM +0700, Eugene Grosbein wrote: On Thu, Dec 06, 2007 at 11:37:50AM +0100, Patrick van Iersel wrote: Here's the situation. We have an web/ftp server with around 74000 users defined in the local unix password database. On 4.9-stable which it is running now, there is no noticable load when lookups are done (logins via ftp, ~user lookups from apache etc.). We want to migrate this system to 6-stable. However on 6-STABLE (FreeBSD 6.3-PRERELEASE #0: Wed Dec 5 13:35:05 CET 2007) these same lookups cause very high load and things slow down to a crawl. Does anybody have an idea what causes this behavior? Thanx in advance for any insights. Take a look to your /etc/nsswitch.conf. If you do not use NIS, try to change lines for 'group' and 'passwd' to look like this: group: files passwd: files The default value is compat on both RELENG_6 and RELENG_7. I don't think switching to files will fix his problem (I'll be very surprised if it does). ___ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Extreme load with local password db lookups
Jeremy Chadwick schrieb: On Thu, Dec 06, 2007 at 06:22:07PM +0700, Eugene Grosbein wrote: On Thu, Dec 06, 2007 at 11:37:50AM +0100, Patrick van Iersel wrote: Here's the situation. We have an web/ftp server with around 74000 users defined in the local unix password database. On 4.9-stable which it is running now, there is no noticable load when lookups are done (logins via ftp, ~user lookups from apache etc.). We want to migrate this system to 6-stable. However on 6-STABLE (FreeBSD 6.3-PRERELEASE #0: Wed Dec 5 13:35:05 CET 2007) these same lookups cause very high load and things slow down to a crawl. Does anybody have an idea what causes this behavior? Thanx in advance for any insights. Take a look to your /etc/nsswitch.conf. If you do not use NIS, try to change lines for 'group' and 'passwd' to look like this: group: files passwd: files The default value is compat on both RELENG_6 and RELENG_7. I don't think switching to files will fix his problem (I'll be very surprised if it does). From: Dennis Berger [EMAIL PROTECTED] Date: Thu, 06 Dec 2007 13:09:11 +0100 To: Jeremy Chadwick [EMAIL PROTECTED] Cc: Eugene Grosbein [EMAIL PROTECTED], Patrick van Iersel [EMAIL PROTECTED],freebsd-stable@freebsd.org Subject: Re: Extreme load with local password db lookups A common way to debug is to isolate the affected systemcalls, by using tools like ktrace or strace. Strace can also record a timestamp, you can see how long it takes to complete a specific systemcall # strace -r -f serverproc Do a single login and then examine the results. happy debugging. regards, Dennis Ok, thanks for the suggestions. I'm a little low on time right now (who isn't) but I'll work on these next week. Best regards, Patrick. ___ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Extreme load with local password db lookups
Jeremy Chadwick wrote: Here's the situation. We have an web/ftp server with around 74000 users defined in the local unix password database. On 4.9-stable which it is running now, there is no noticable load when lookups are done (logins via ftp, ~user lookups from apache etc.). We want to migrate this system to 6-stable. However on 6-STABLE (FreeBSD 6.3-PRERELEASE #0: Wed Dec 5 13:35:05 CET 2007) these same lookups cause very high load and things slow down to a crawl. Does anybody have an idea what causes this behavior? Thanx in advance for any insights. Take a look to your /etc/nsswitch.conf. If you do not use NIS, try to change lines for 'group' and 'passwd' to look like this: group: files passwd: files The default value is compat on both RELENG_6 and RELENG_7. I don't think switching to files will fix his problem (I'll be very surprised if it does). See http://www.freebsd.org/cgi/query-pr.cgi?pr=75855 It seems the regression from RELENG_4 is still here. There are so many regressions in performance that I still prefer to invest time to patch bsd.ports.mk to support 4.x (and have a success, I use fresh ports with 4.x these days) then upgrade my UP boxes to 6.x and suffer from loss of performaince. Eugene Grosbein ___ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Extreme load with local password db lookups
On Fri, Dec 07, 2007 at 08:44:37AM +0100, Patrick van Iersel wrote: See http://www.freebsd.org/cgi/query-pr.cgi?pr=75855 It seems the regression from RELENG_4 is still here. There are so many regressions in performance that I still prefer to invest time to patch bsd.ports.mk to support 4.x (and have a success, I use fresh ports with 4.x these days) then upgrade my UP boxes to 6.x and suffer from loss of performaince. For what it's worth, Eugene's suggestion of changing nsswitch.conf actually helps. It was mentioned in the PR above as well. It's still a workaround but it works good enough for me now. It would be nice if you make a followup to the PR for the record with a notice about your problem and mention 6.3-PRERELEASE there. Eugene Grosbein ___ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Extreme load with local password db lookups
From: Eugene Grosbein [EMAIL PROTECTED] Organization: SVZServ Date: Fri, 07 Dec 2007 12:40:42 +0700 To: Jeremy Chadwick [EMAIL PROTECTED] Cc: Patrick van Iersel [EMAIL PROTECTED], freebsd-stable@FreeBSD.org Subject: Re: Extreme load with local password db lookups Jeremy Chadwick wrote: Here's the situation. We have an web/ftp server with around 74000 users defined in the local unix password database. On 4.9-stable which it is running now, there is no noticable load when lookups are done (logins via ftp, ~user lookups from apache etc.). We want to migrate this system to 6-stable. However on 6-STABLE (FreeBSD 6.3-PRERELEASE #0: Wed Dec 5 13:35:05 CET 2007) these same lookups cause very high load and things slow down to a crawl. Does anybody have an idea what causes this behavior? Thanx in advance for any insights. Take a look to your /etc/nsswitch.conf. If you do not use NIS, try to change lines for 'group' and 'passwd' to look like this: group: files passwd: files The default value is compat on both RELENG_6 and RELENG_7. I don't think switching to files will fix his problem (I'll be very surprised if it does). See http://www.freebsd.org/cgi/query-pr.cgi?pr=75855 It seems the regression from RELENG_4 is still here. There are so many regressions in performance that I still prefer to invest time to patch bsd.ports.mk to support 4.x (and have a success, I use fresh ports with 4.x these days) then upgrade my UP boxes to 6.x and suffer from loss of performaince. For what it's worth, Eugene's suggestion of changing nsswitch.conf actually helps. It was mentioned in the PR above as well. It's still a workaround but it works good enough for me now. Thanx guys. Best regards, Patrick. ___ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Extreme load with local password db lookups
On Fri, Dec 07, 2007 at 08:44:37AM +0100, Patrick van Iersel wrote: From: Eugene Grosbein [EMAIL PROTECTED] See http://www.freebsd.org/cgi/query-pr.cgi?pr=75855 It seems the regression from RELENG_4 is still here. There are so many regressions in performance that I still prefer to invest time to patch bsd.ports.mk to support 4.x (and have a success, I use fresh ports with 4.x these days) then upgrade my UP boxes to 6.x and suffer from loss of performaince. For what it's worth, Eugene's suggestion of changing nsswitch.conf actually helps. It was mentioned in the PR above as well. It's still a workaround but it works good enough for me now. I stand corrected. :-) The PR referenced by Eugene is dead on. The priority on that PR should really be changed to medium or high, because the impact is major. I'm sure large hosting/shell providers are being bitten by this. -- | Jeremy Chadwickjdc at parodius.com | | Parodius Networking http://www.parodius.com/ | | UNIX Systems Administrator Mountain View, CA, USA | | Making life hard for others since 1977. PGP: 4BD6C0CB | ___ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to [EMAIL PROTECTED]
