MySQL Bugs: #790: mysql with linuxthreads on freebsd ignoring wait

Bug #790	mysql with linuxthreads on freebsd ignoring wait_timeout parameter
Submitted:	4 Jul 2003 6:28	Modified:	9 Apr 2008 5:43
Reporter:	Dziugas Baltrunas	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server	Severity:	S2 (Serious)
Version:	4.0.13	OS:	FreeBSD (FreeBSD 5.0-RELEASE-p2)
Assigned to:		CPU Architecture:	Any

Description:
When MySQL is compiled from ports collection with LinuxThreads (2.2.3_12) under FreeBSD 5.0 RELEASE, wait_timeout parameter gets ignored. This is valid both setting value in my.cnf or from command line (SET GLOBAL wait_timeout). 

I heard that same issue is with other versions of mysql (both 4.0.x and 3.23.x releases) as well as different versions of FreeBSD. 

This bug causes persistent connections to hang for *a long* time. 

How to repeat:
Try to build mysql with linuxthreads, set wait_timeout parameter to reasonable *low* value, start the server and then open persistent connection with non-interactive client (like php or similar). You should see newly created process hanging in "SHOW PROCESSLIST" longer than wait_timeout is. 

Suggested fix:
still missing, but related information may by found at Jeremy's archive:
http://jeremy.zawodny.com/blog/archives/000173.html
http://jeremy.zawodny.com/blog/archives/000203.html
http://jeremy.zawodny.com/blog/archives/000264.html

and mainly:
http://jeremy.zawodny.com/blog/archives/000697.html

I have deffered this bug for the moment as this is a FreeBSD kernel bug that we can't do much about.

I have updated our manual to make FreeBSD users aware of the problem with wait_timeout.

Many thanks for writing a bug report.

I tested this again and with newer version of MySQL and newer version of FreeBSD this issue has been gone. I will close this bug now.