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Displaying posts with tag: core file (reset)
How to obtain all executing queries from a core file

When investigating core files from crashes, one can quite easily figure out which query crashed, as we've seen.

Sometimes you want to just list all the currently executing statements, this is useful for diagnosing hangs or corruptions.

At least GDB 7 supports python macros, which can help us a lot here.   I use a core file from 5.5.27, also a non-debug build but not "stripped".   So it's a standard build made with -g allowing us to reference symbols.

I wrote a simplistic macro to iterate through mysqld's global "threads" variable.
This is what my …

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how to debug a mysqld core file from an rpm install

You have a typical rpm installation of mysql, and the process is crashing. Here are the basic steps needed to find out more info about a crash:

  • Configure the OS to be able to create corefiles. (Redhat details), (Solaris details)
  • Tell mysqld to create a corefile by adding the following options to my.cnf:


[mysqld_safe]
core-file-size=unlimited

[mysqld]
core-fileUsually the corefile will be created in the datadir with a name like core.2921 where 2921 was the pid of the running process. The location is configurable on most OS's.

You'll need the following to study the core file:

  • exact mysqld binary that created the core file
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