On Fri, Aug 08, 2003 at 04:18:51PM -0700, Jeremy Zawodny wrote: > On Thu, Aug 07, 2003 at 09:07:41PM -0500, Dan Nelson wrote: > > In the last episode (Aug 07), Jeremy Zawodny said: > > > > I've been on the box at the mysql prompt quite a few times when it > > > > has happened and there was always a large amount of threads waiting > > > > for a lock to clear, and as soon as they went through nothing could > > > > connect, but this doesn't happen everytime we have a large queue, > > > > so there must be something else in the mix. If you think any info > > > > I have might help you, let me know. I'd love to hear any ideas you > > > > have. > > > > > > I don't know how to do this with pthreads but with LT, I'd like to > > > identify a few of the pids for the struck threads and then get a > > > snapshot of the call stack to see where they're waiting. > > > > The pstack command (ports/sysutils/pstack) knows about FreeBSD's libc_r > > threads, so you can run that to get a snapshot of mysql's thread > > state. > > Just caught one. We have nealy 300 "stuck" connections and they all > look like this right now: > > 45855: /home/y/libexec/mysqld > ----------------- thread 0 (running) ----------------- > 683f4de8 _sigsuspend (8e0ffbc0, 4, 8e0ff9c4, 683644de, 68373e64, 8dfff9e8) + 8 > 68364534 __pthread_suspend_old (8e0ffbc0, 0, 8e0ffa04, 6836183a, 68373e64, > 3ce3500c) + 64 > 683619b6 __pthread_alt_lock (8366b04, 0, 8e0ffa34, 68364c5a, 0, 3ce3500c) + 18a > 68364db2 pthread_mutex_lock (8366af4, 3ce35504, 0, 826a3b9, 3ce35504, 3ce3500c) + > 166 > 8078c01 ip_to_hostname__FP7in_addrPUi (3ce35504, 8e0ffa9c, 8e0ffb24, 807d490, > 3ce1d280, 3ce35504) + f1 > 807d4a0 check_connections__FP3THD (3ce35000, 0, 1, 807d7dc, 68373e64, 8e0ffbc0) + c4 > 807d8b2 handle_one_connection (3ce35000, 2, 8e0ffc78, 68365e77, 68373e64, 8e0ffbb8) > + 11a > 68365f2d _init (8e0ffbc0, 8e0ffbc0, 0, 0, 0, 0) + f119 > > Now, to figure out what that's telling us...
Setting skip-name-resolve will avoid this code path and the bug. It looks like some DNS funkyness... Jeremy -- Jeremy D. Zawodny | Perl, Web, MySQL, Linux Magazine, Yahoo! <[EMAIL PROTECTED]> | http://jeremy.zawodny.com/ MySQL 4.0.13: up 7 days, processed 250,298,423 queries (400/sec. avg) -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
