Re: MySQL4 on Linux with Intel Hyperthreading CPUs?
Hi Group, I have a new dedicated mysql 4.0.5 server running redhat 8.0 that we are testing. The new server is a dual Intel Xeon 2.4GHZ with hyperthreading enabled, so Linux thinks there are 4 cpu's rather than the 2 real CPU's. I have a similar hardware running mysql 3.23.52 on linux. In my special case mysql has to handle few but very straining queries (running 10-30 seconds). As of my experience, mysql is not able to use both physical processors to process one of these jobs... it really bunches two virtual processors (even though top shows 0% load for the 3 remaining processors) but not physical processor spanning. I would like one single mysql process to make use of all available cpu capacity if no concurrent processes demand attention. But: is this possible using mysql 3.x? Thanks in advance Keith Sauvant - Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail [EMAIL PROTECTED] To unsubscribe, e-mail [EMAIL PROTECTED] Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
RE: MySQL4 on Linux with Intel Hyperthreading CPUs?
If the OS can use hyperthreading, fortunately, benchmarks are showing that there's no preformance hits because of overhead created trying to keep resource contention down. This is good! So if your system _can_ support hyperthreading, leaving it on won't hurt, if it doesn't improve your system's performance. If the OS doesn't support hyperthreading, then it just won't use it, obviously, so it's not an issue. But as far as MySQL's usage and performance in particular with hyperthreading procs, I don't have any experience :/ Mike -Original Message- From: John Dell [mailto:[EMAIL PROTECTED]] Sent: Wednesday, December 11, 2002 6:15 PM To: [EMAIL PROTECTED] Subject: MySQL4 on Linux with Intel Hyperthreading CPUs? Hi, I have a new dedicated mysql 4.0.5 server running redhat 8.0 that we are testing. The new server is a dual Intel Xeon 2.4GHZ with hyperthreading enabled, so Linux thinks there are 4 cpu's rather than the 2 real CPU's. Anybody have any experience with this and whether it can cause any problems with MySQL or Linux? Any performance reasons to enable/disable hyperthreading? Thanks! John Dell [EMAIL PROTECTED] - Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail [EMAIL PROTECTED] To unsubscribe, e-mail [EMAIL PROTECTED] Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php - Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail [EMAIL PROTECTED] To unsubscribe, e-mail [EMAIL PROTECTED] Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
Re: MySQL4 on Linux with Intel Hyperthreading CPUs?
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Keith Sauvant wrote: Hi Group, I have a new dedicated mysql 4.0.5 server running redhat 8.0 that we are testing. The new server is a dual Intel Xeon 2.4GHZ with hyperthreading enabled, so Linux thinks there are 4 cpu's rather than the 2 real CPU's. I have a similar hardware running mysql 3.23.52 on linux. In my special case mysql has to handle few but very straining queries (running 10-30 seconds). As of my experience, mysql is not able to use both physical processors to process one of these jobs... it really bunches two virtual processors (even though top shows 0% load for the 3 remaining processors) but not physical processor spanning. I would like one single mysql process to make use of all available cpu capacity if no concurrent processes demand attention. But: is this possible using mysql 3.x? This would require operating system support for balancing a single process or thread across multiple CPUs, which I've never heard of (but might exist in some more exotic operating systems). In MySQL, each connection, and thus each query, maps to a thread. On almost all operating systems and hardware, any one thread or process executes on a single CPU at any one time. CPU cycles are not generally a 'sharable' resource, except in parallel processing type scenarios, which requires software to be built specifically for that kind of operation, and which is only useful to solve certain specific types of problems. -Mark - -- MySQL 2003 Users Conference - http://www.mysql.com/events/uc2003/ For technical support contracts, visit https://order.mysql.com/?ref=mmma __ ___ ___ __ / |/ /_ __/ __/ __ \/ / Mark Matthews [EMAIL PROTECTED] / /|_/ / // /\ \/ /_/ / /__ MySQL AB, Full-Time Developer - JDBC/Java /_/ /_/\_, /___/\___\_\___/ Flossmoor (Chicago), IL USA ___/ www.mysql.com -BEGIN PGP SIGNATURE- Version: GnuPG v1.1.90 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQE9+K+ZtvXNTca6JD8RAujYAJ96qlQMqS4Lwk1PakCDOzEtna2VYQCePviC taG39ZYIVeR44ZkP8U0A9y4= =o4zz -END PGP SIGNATURE- - Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail [EMAIL PROTECTED] To unsubscribe, e-mail [EMAIL PROTECTED] Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
RE: MySQL4 on Linux with Intel Hyperthreading CPUs?
We're running a 4x1.6Ghz Xeon box. Linux reports 8 procs. We've been running MySQL on it for a couple months now in production under a good load. Database sits around 60GB with anywhere from 200-800 concurrent connections. Both InnoDB and MyISAM types are used and we're not having a single problem with it. (I don't think I've ever seen the machine go above a load of 2...) -Original Message- From: John Dell [mailto:[EMAIL PROTECTED]] Sent: Wednesday, December 11, 2002 5:15 PM To: [EMAIL PROTECTED] Subject: MySQL4 on Linux with Intel Hyperthreading CPUs? Hi, I have a new dedicated mysql 4.0.5 server running redhat 8.0 that we are testing. The new server is a dual Intel Xeon 2.4GHZ with hyperthreading enabled, so Linux thinks there are 4 cpu's rather than the 2 real CPU's. Anybody have any experience with this and whether it can cause any problems with MySQL or Linux? Any performance reasons to enable/disable hyperthreading? Thanks! John Dell [EMAIL PROTECTED] - Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail [EMAIL PROTECTED] To unsubscribe, e-mail [EMAIL PROTECTED] Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php - Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail [EMAIL PROTECTED] To unsubscribe, e-mail [EMAIL PROTECTED] Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
