현재 호스트와 UML에 대한 새로운 성능 패치를 테스트할 프리몬트 데이터 센터(host9)의 호스트에 있는 몇 명의 Linode 64 사용자를 찾고 있습니다.
UML은 Linux의 기능인 ptrace를 사용하여 애플리케이션에서 만든 시스템의 인터셉트 시스템 호출로 작동합니다. UML이 시스템 호출을 할 때 호스트는 호출을 가로채고, UML 내부에서 작업을 수행하고, 해당 시스템 호출을 호스트의 "getpid"로 변환하여 호스트의 시스템 호출을 null-ifies합니다. 이 문제는 호스트에서 두 개의 컨텍스트 스위치를 생성한다는 것입니다.
[url=http://perso.wanadoo.fr/laurent.vivier/UML/
]sysemu 패치[/url] 호스트와 UML에서 "getpid" 실행하지 않습니다, 따라서 컨텍스트 스위치의 수를 2에서 1로 감소합니다.
[b]벤치마크[/b]
다음은 Mysql의 실행-모든 테스트 스크립트를 사용한 몇 가지 "실제" 벤치 마크입니다:
http://www.theshore.net/~caker/uml/sysemu-benchmarks.txt
요컨대, 테스트는 sysemu 패치 없이 실행했던 것보다 [b]33% 더 빠릅[/b]니다.
[b]세부[/b]
[목록] [*] 호스트25로 마이그레이션하여 이전 호스트에 슬롯을 예약된 상태로 유지합니다(다시 마이그레이션해야 하는 경우). 이전에 마이그레이션한 적이 없는 경우 파일 시스템 이미지를 새 호스트로 이동하는 자동화된 프로세스입니다. 최종에는 변경이 필요하지 않으며, 가동 중지 시간은 이미지를 복사하는 데 걸리는 시간(일반적으로 3GB의 경우 15분 미만)으로 제한됩니다.
[*] 2.4.26-linode29-1um 커널을 부팅하도록 구성 프로파일을 설정합니다.
[*] 부러트리려고 합니다[/list]
며칠 동안 상황이 잘 진행된다면 안정적이라고 생각하고 서버를 대중에게 공개할 것입니다. 몇 주 후, 우리는 이 커널로 다른 호스트를 이동할 수 있습니다.
둘째, 이것은 호스트에서 현재의 업그레이드 버전 2.6.4 커널인 2.6.7-rc1을 테스트하는 데 도움이 될 것입니다.
셋째, 나는 또한 2.4.26-linode29-1um 커널을 테스트하는 사람 중 몇 명이 여전히 sysemu 패치없이 호스트에서 제대로 작동하는지 확인하면 좋겠습니다. 이 커널에 대한 귀하의 경험을 알려주십시오. sysemu가 활성화되지 않은 호스트에서는 이전 linode 커널과 동일하게 수행해야 합니다.
당신이 관심이 있다면 알려주세요...
감사!
-Chris
댓글 (17)
Three updates in one test? You’ve got ball-balls Chris!
😀
— James
I’m interested….let do it!
[quote:0999715663=”mcowger”]I’m interested….let do it![/quote]
Great. I haven’t patched a 2.6-um kernel with the sysemu patches yet, so for now go with the 2.4.26-linode29-1um kernel. I’ll update this thread when the 2.6 version is out.
Thanks!
-Chris
I’m game. What do I need to do?
Terry
[quote:31f75d1a84=”terryr”]I’m game. What do I need to do?[/quote]
Login, shutdown, and press the migrate button. After the migration, reboot.
BTW, 5 users have moved over to host25 and so far so good.
-Chris
Done! Are you looking for any specific feedback?
[quote:5c2da2598a=”terryr”]Done! Are you looking for any specific feedback?[/quote]
I pretty much know there’s a performance improvement already, but hearing about that would be nice. It might be kind of difficult to pin down, unless you run specific tests and compare them against the linode28 kernel. Secondly, I wanted to generate some load on the host kernel, and the linode29 kernel, just to make sure the stability is still there.
Thanks!
-Chris
I loaded a fresh Fedora Core 1 distro. Noticed immediately how much faster it is. Ran locate -u which was noticeably faster. Ran top and saw something strange. About every two seconds, there’s a cycle. See pics below. irq goes up to 0.9% and softirq goes up to 49.5% and iowait is 49.5%, then it all drops to 0 for 2 seconds and goes back up again for two seconds.
[img]http://futurecourse.com/files/no_softirq.gif[/img]
[img]http://futurecourse.com/files/softirq.gif[/img]
I don’t recall this happening when I looked at top on the old host. Or did I just miss it?
Terry
I am seeing stragne problems with mysql that I did not see before moving over. Whenever, I try to connect I get this message:
ERROR 2002: Can’t connect to local MySQL server through socket ‘/var/run/mysqld/mysqld.sock’ (2)
This is because mysqld either keeps hanging or completely crashes.
It will run fine for a few hours and then just die. I can’t explain why.
I will keep everyone posted.
John
[quote:04e5122a27=”jftuga”]I am seeing stragne problems with mysql that I did not see before moving over. Whenever, I try to connect I get this message:
ERROR 2002: Can’t connect to local MySQL server through socket ‘/var/run/mysqld/mysqld.sock’ (2)
This is because mysqld either keeps hanging or completely crashes.
It will run fine for a few hours and then just die. I can’t explain why.[/quote]
I’ve noticed your Linode using a lot of swap, so perhaps you’re running out of memory and the OOM (Out Of Memory) killer is kicking in…
-Chris
[quote:2ab259ee1d=”terryr”]I don’t recall this happening when I looked at top on the old host. Or did I just miss it? [/quote]
I’ll give this a shot, too, but.. would you mind rebooting into the linode28 kernel and seeing if you can reproduce this?
I somehow doubt the SYSEMU patch would be the cause of this, or the mysql problem…
-Chris
I have modified the mysql server for a small memory footprint using the my-small.cnf that comes with the src distro.
I will let you kno if this helps.
Also, I am using a lot of swap, and am considering upgrading to a 96 or 128 when they become available.
-John
[quote:befbb85d95=”caker”]I’ll give this a shot, too, but.. would you mind rebooting into the linode28 kernel and seeing if you can reproduce this? [/quote]
Did that yesterday with no change, but when I checked this morning, I’m at 0.1% for irq and softirq and it cycles with iowait at 0.2%. The high initial numbers didn’t seem to affect performance at all.
—
Terry
where is the migrate button? I shutodown and clicked around but I never found it.
[quote:f84ba42be4=”bakins”]where is the migrate button? I shutodown and clicked around but I never found it.[/quote]
This is something I have to set up for you first (which I just did). Login and you should see it.
Testing has gone very well. In fact, the machine is “live”, 2.6.7-rc1 is performing great (on the host), and the linode29 kernel works perfectly on SYSEMU and non-SYSEMU patched hosts.
I consider this test done, but go ahead and make the move — let me know what you think.
-Chris
I was out of town for a week.
I’ve now migrated and am testing. Everything seems to work. I’m testing out plone. I’ll do some tests and get back.
interesting… is this similar to the skas patch?