Bug #39866 for DBD-mysql: segfault on mysql

Tue Oct 07 11:38:43 2008 ELACOUR [...] cpan.org - Ticket created

Subject:

segfault on mysql_ping

Hi, I would like to report information about this problem (see also http://bugs.mysql.com/bug.php?id=36810). Using RT on Debian lenny, and fastcgi, we encouter sometimes this problem (the fastcgi process segfault). It's in the DBD::mysql ping function, here are the steps I used to reproduce it: - set low timeout in my.cnf (10s) - start the app (RT) * I show a first connect and ping - wait for timeout using SHOW FULL PROCESSLIST - connect to the app * works fine, RT reconnects, ping works, adding debug in mysql_db_reconnect function I see that "imp_dbh->auto_reconnect" is false and so there is no automatic reconnect from DBD, but RT has code to do it and does it. - wait timeout another time - reconnect to the app * mysql_db_reconnect detect now that auto_reconnect is on (why???) try to reconnect, return TRUE, then the next call to mysql_ping in the DBD::mysql ping function segfault. Please don't hesitate to ask if you need more debugging to solve this :)

Tue Oct 07 19:30:59 2008 BRONG [...] cpan.org - Correspondence added

On Tue Oct 07 11:38:43 2008, ELACOUR wrote: Show quoted text

> It's in the DBD::mysql ping function, here are the steps I used to > reproduce it:

Here's a simpler way to reproduce it. Run the attached program :)

#!/usr/bin/perl -w use strict; use warnings; use DBI; my ($host, $database, $username, $password) = @ARGV; die "Usage: $0 host database username password\n" unless $password; my $dbh = DBI->connect("DBI:mysql:database=$database;host=$host", $username, $password); die "Connection failed " . DBI->errstr() unless $dbh; $dbh->{mysql_auto_reconnect} = 1; my $threadid = $dbh->{mysql_thread_id}; my $dbh2 = DBI->connect("DBI:mysql:database=$database;host=$host", $username, $password); die "Connection failed " . DBI->errstr() unless $dbh2; $dbh2->do("KILL $threadid"); $dbh2->disconnect(); sleep 1; my ($val) = $dbh->selectrow_array("SELECT 1"); print "You do not have the bug. Also, autoreconnection: " . ($val ? "succeeded" : "failed") . "\n";

Tue Oct 07 19:31:01 2008 The RT System itself - Status changed from 'new' to 'open'

Tue Oct 07 19:58:25 2008 daniel.frett [...] ccci.org - Correspondence added

From:

daniel.frett [...] ccci.org

On Tue Oct 07 11:38:43 2008, ELACOUR wrote: Show quoted text

> Hi, > > I would like to report information about this problem (see also > http://bugs.mysql.com/bug.php?id=36810). > > Using RT on Debian lenny, and fastcgi, we encouter sometimes this > problem (the fastcgi process segfault). > > It's in the DBD::mysql ping function, here are the steps I used to > reproduce it: > > - set low timeout in my.cnf (10s) > - start the app (RT) > * I show a first connect and ping > - wait for timeout using SHOW FULL PROCESSLIST > - connect to the app > * works fine, RT reconnects, ping works, adding debug in > mysql_db_reconnect function I see that "imp_dbh->auto_reconnect" is > false and so there is no automatic reconnect from DBD, but RT has code > to do it and does it. > - wait timeout another time > - reconnect to the app > * mysql_db_reconnect detect now that auto_reconnect is on (why???) try > to reconnect, return TRUE, then the next call to mysql_ping in the > DBD::mysql ping function segfault. > > Please don't hesitate to ask if you need more debugging to solve this :) > >

This is a duplicate of this bug report. http://rt.cpan.org/Public/Bug/Display.html?id=37027 -Daniel

Fri Oct 10 05:39:48 2008 EVDB [...] cpan.org - Correspondence added

I have also seen this problem: http://www.mail-archive.com/dbi-users@perl.org/msg31416.html Please let me know if I can help to test any code :) Cheers, Edmund

Tue Mar 24 08:30:37 2009 timo2009 [...] ballin.se - Correspondence added

From:

timo2009 [...] ballin.se

On Fr. 10. Okt. 2008, 05:39:48, EVDB wrote: I can confirm this problem on Solaris: With Apache 2.2 and mod_perl2 ( sql authentification module - similar to Apache::AuthDBI ) while connecting to a external mysql 4.1.22 DB. But I think the "trigger" is the short connect timout on that server.

Download perl_dbd_mysql_report.txt.gz
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Tue Mar 24 08:55:34 2009 timo2009 [...] ballin.se - Broken in 4.010 added

Tue Mar 24 08:58:17 2009 timo2009 [...] ballin.se - Broken in 4.010 deleted

Thu Sep 12 18:51:56 2013 MICHIELB [...] cpan.org - Correspondence added

duplicate of https://rt.cpan.org/Ticket/Display.html?id=37027

Thu Sep 12 18:51:56 2013 MICHIELB [...] cpan.org - Status changed from 'open' to 'rejected'

Bug #39866 for DBD-mysql: segfault on mysql_ping