Re: [Zope] Re: Give it a rest + answers. (Re: Re: Zope + Apache on Quad Debian machine)
Andrew Sawyers wrote: The other engineer was me, and it was close enough to double the load per instance, per cpu. tangential question: I'm assuming you were using LVS in front of these boxes? If so, how'd you get the both clients on the box accessible by LVS? 2 ip addresses? cheers, Chris -- Simplistix - Content Management, Zope Python Consulting - http://www.simplistix.co.uk ___ Zope maillist - Zope@zope.org http://mail.zope.org/mailman/listinfo/zope ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope-dev )
Re: [Zope] Re: Give it a rest + answers. (Re: Re: Zope + Apache on Quad Debian machine)
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Chris Withers wrote: Andrew Sawyers wrote: The other engineer was me, and it was close enough to double the load per instance, per cpu. tangential question: I'm assuming you were using LVS in front of these boxes? If so, how'd you get the both clients on the box accessible by LVS? 2 ip addresses? Nope, different port numbere. LVS is configured per-service, rather than per-IP. Tres. - -- === Tres Seaver +1 202-558-7113 [EMAIL PROTECTED] Palladion Software Excellence by Designhttp://palladion.com -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.1 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFEIo3E+gerLs4ltQ4RAmBaAKCwiU6E/cnJNRQBTSNDk32j+hKRkACgjhgn awM/z7gLOzscAeCzKY5Aexk= =0HJ9 -END PGP SIGNATURE- ___ Zope maillist - Zope@zope.org http://mail.zope.org/mailman/listinfo/zope ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope-dev )
[Zope] Re: Give it a rest + answers. (Re: Re: Zope + Apache on Quad Debian machine)
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Dario Lopez-Kästen wrote: snip Let me be the first to admit my total lack of knowledge of kernel task schedulers, but generally speaking, unless the scheduler makes sure that a threaded python process never ever gets distributed over two processors simultaniously, then the GIL *will* be an issue. The hypothesis is that the scheduler notices that threads in a single Python process are always blocking on a single kernel resource (the semaphore / mutex which is the GIL), and hence migrates them all to the same CPU (over time). I could imagine that this is like the hand-rolled assembly vs. compiler-generated code case: older kernels (like the one your old app was dpeloyed atop, perhaps?) didn't have such smarts, but newsr ones do. In any event, I'd love to be proved wrong about the need for taskset (especially if someone comes up with measurable data to that effect) because it means that my sysadmins can simplify their setup for managing Zope (making Zope even more acceptable :-). WHile at ZC, one of the other engineers and I did some testing on SMB boxes, and found that one appserver per CPU gave us near linear scaling of the application, without any explicit affinity set. I don't have the numbers (we were using stock Dell 1U dual CPU boxes, I think), but the win seemed clear enough that we quit invesigating taskset. Tres. - -- === Tres Seaver +1 202-558-7113 [EMAIL PROTECTED] Palladion Software Excellence by Designhttp://palladion.com -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.1 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFEIVAK+gerLs4ltQ4RAnb9AKC7qw38+BqNdAbY79bqPR4/G7USCwCbBmit UX+GcftjNQ5fUKajALsEbSk= =+E5c -END PGP SIGNATURE- ___ Zope maillist - Zope@zope.org http://mail.zope.org/mailman/listinfo/zope ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope-dev )
Re: [Zope] Re: Give it a rest + answers. (Re: Re: Zope + Apache on Quad Debian machine)
On Wed, 2006-03-22 at 08:24 -0500, Tres Seaver wrote: -BEGIN PGP SIGNED MESSAGE- Hash: SHA1 WHile at ZC, one of the other engineers and I did some testing on SMB boxes, and found that one appserver per CPU gave us near linear scaling of the application, without any explicit affinity set. I don't have the numbers (we were using stock Dell 1U dual CPU boxes, I think), but the win seemed clear enough that we quit invesigating taskset. The other engineer was me, and it was close enough to double the load per instance, per cpu. If he needs to test it, the numbers are easy to get. Run a single instance on a SMP Server, and hit it with load. You will get Y. Run another instance and spread that load across both instances and you will get nearly 2xY. Take a single cpu server and run 1 instance and load test it, and you'll get Y. Take that same single cpu server and run 2 instance, and load test it across both instances, and you'll get Y. These tests were done on both Linux and FreeBSD and both were approximately the same. The conclusion was, no further complexity is required to get a substantial performance benfit by running SMP Servers with multiple Zeo Clients instances, where the # of CPUS == the # of Zeo Client instances. This has been posted to the lists serveral times BTW. The only snafu is to make sure you have enough RAM to run several zeo client instances. If you've got a 4way server, I'd recommend 16GBs of RAM if it's a big site. I personally like to put as much ram into a server as it can physically handle. Andrew Sawyers Tres. - -- === Tres Seaver +1 202-558-7113 [EMAIL PROTECTED] Palladion Software Excellence by Designhttp://palladion.com -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.1 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFEIVAK+gerLs4ltQ4RAnb9AKC7qw38+BqNdAbY79bqPR4/G7USCwCbBmit UX+GcftjNQ5fUKajALsEbSk= =+E5c -END PGP SIGNATURE- ___ Zope maillist - Zope@zope.org http://mail.zope.org/mailman/listinfo/zope ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope-dev ) ___ Zope maillist - Zope@zope.org http://mail.zope.org/mailman/listinfo/zope ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope-dev )