René Fournier wrote: > Hello, > > I have a command-line PHP script--called Listener--that is designed to > run indefinitely with a predictable CPU usage and memory footprint. In a > nutshell, it's a multi-client socket server that waits for incoming > connections, processes incoming data, stores results in a MySQL > database, and basically gets on with its life. And it works. No errors > or serious problems to speak of. And I've been running it for a couple > years on an Xserve dual-G5 2GHz w/ OS X Server 10.4.11). Six months ago, > the program would run for days, even a couple weeks, without a hitch. > The only reason I would stop the script is for some other purpose, like > a software update. > > However, the number of socket clients connecting in the past 3-4 months > has steadily increased, and this seems to have exposed (if not created) > a strange performance "issue" with PHP 5.2.4, MySQL 5.0.45 and/or Mac OS > X Server 10.4.11. (I say "and/or" because I am unsure where the > problem's cause really lies.) Basically, after the script has been > running for a day or so (processing essentially the amount data that > used to take two weeks), the CPU usage of the machine goes from 30% > (normal) to 80-90%. This appears to be irrespective of the number of > clients connected to the server at the time, but rather the amount of > time the script has been running (and therefore cumulative cycles it's > operated, data processed, MySQL queries executed, etc.). And the CPU > usage stays high, even when the actual load (number of clients) > decreases. At this time, if I run top, I get the following info: > > 22512 mysqld 91.6% 8:22:12 31 106 125 305M+ 3.20M 260M > 475M > 17104 php 7.2% 81:14.01 1 15 145 5.08M 7.80M 10.9M- > 87.5M > 22537 Terminal 6.6% 2:59:59 22 176 240 12.3M 21.2M 18.3M- > 236M > [...] > > At first I thought, okay, it's MySQL's fault. Maybe a lot of > slow-running queries. But the slow query log is pretty clean. So maybe > it's a combination of Mac OS X and MySQL and PHP? I Googled for a > similar problem, and finally ran across this article: > > http://www.shawnhogan.com/2005/10/mysql-problems-on-mac-os-x-server.html > > ...where the author describes a very similar CPU usage pattern. I tried > his suggested fixes and they seemed to have helped a little (or maybe > it's my wishful thinking--hard to tell), since the high CPU load issue > doesn't appear to happen as soon... But it still happens. > > Anyway, I'm really stumped as to what to do next, where to look, etc. If > I stop the script, and restart it (but not the MySQL itself), CPU usage > goes back to normal--for about a day or two. > > The only thing I thought might be connected is how many short-lived PHP > child processes Listener creates--around 20-30,000 per day. Sounds > higher, but on average it's just one every 2-3 seconds. Anyway, although > the number of child processes isn't concurrent, would there be a problem > with the number of historical child processes in view of ulimits or > kern.maxfilesperproc? > > Anyway suggestions, tips, or links are much appreciated. Thanks. > > ...Rene > I have a server that "listens" like yours does. I get 80k - 85k connections a day to it. When I first started it, I was only getting about 3k of connections aday. Then I upped the listening pattern and it tanked. I noticed that all my mail/web/db connections just sat there. When I investigated, I found that the number of connections to the server was being overloaded. So I increased the kern.maxfilesperproc setting to 32000. All the problems went away. I have about have the horse power you do, running OpenBSD 4.1, and it runs great now as my "listener" / web / ftp / mail / named / database / spam filter / etc... One question about the "listener" program, does it maintain a connection to the DB or does it open/close a connection upon each socket connection? If it does the latter, you might look into using a constant connection rather then opening/closing on a per connection basis. -- Jim Lucas "Some men are born to greatness, some achieve greatness, and some have greatness thrust upon them." Twelfth Night, Act II, Scene V by William Shakespeare -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
