Bug #20465 .
Submitted: 14 Jun 2006 16:37 Modified: 3 Aug 2006 20:01
Reporter: Mike Harris Email Updates:
Status: Not a Bug Impact on me:
Category:MySQL Server Severity:S5 (Performance)
Version:. OS:.
Assigned to: CPU Architecture:Any

[14 Jun 2006 16:37] Mike Harris
I am having a problem dumping a database. I'm using;

/usr/local/mysql/bin/mysqldump --opt -u user -ppass database

I get;

*** glibc detected *** double free or corruption (!prev): 0x001c5800 ***

part way through the dump and it needs a restart to make mysql responsive again...

The version of glibc provided with CentOS 4.3 performs additional internal sanity checks to prevent and detect data corruption as early as possible. By default, should corruption be detected, a message similar to the following will be displayed on standard error (or logged via syslog if stderr is not open):

*** glibc detected *** double free or corruption: 0x0937d008 ***

By default, the program that generated this error will also be killed; however, this (and whether or not an error message is generated) can be controlled via the MALLOC_CHECK_ environment variable. The following settings are supported:

0 Do not generate an error message, and do not kill the program
1 Generate an error message, but do not kill the program
2 Do not generate an error message, but kill the program
3 Generate an error message and kill the program


If MALLOC_CHECK_ is explicitly set a value other than 0, this causes glibc to perform more tests that are more extensive than the default, and may impact performance.Should you have a program from a third party ISV that triggers these corruption checks and displays a message, you should file a defect report with the application's vendor, since this indicates a serious bug.

Mysql 5.0.15, Apache/2.0.55, php 5.0.5, Centos4.3

How to repeat:
dump large database

Suggested fix:
not known
[14 Jun 2006 16:38] Mike Harris
[15 Jun 2006 16:18] Mike Harris
[15 Jun 2006 16:18] Mike Harris
[3 Aug 2006 20:01] Mike Harris
If not a bug. Please advise on a solution.

Or at least point me in the right direction.
I don't have a backup of my database...