Using the libcoredumper¶
This feature was implemented in Percona Server for MySQL 5.7.31-34 and has been tested against the supported operating systems for that version.
|Red Hat Enterprise Linux and derivatives
|6, 7, 8
|16.04, 18.04, 20.04
The documented moment of a computer when either the computer or an application crashed is a core dump file. Developers examine the dump as one of the tasks when searching for the cause of a failure.
libcoredumper is a free and Open Source fork of
google-coredumper, enhanced to work on newer Linux versions, and GCC and CLANG.
Test this tool in a safe environment before using in production.
Enable the libcoredumper¶
Enable core dumps for troubleshooting purposes.
To enable the
libcoredumper, add the
coredumper variable to the
mysqld section of
my.cnf. This variable is independent of the older
The variable can have the following possible values:
|The core dump is saved under MySQL datadir and named
|A path ending with
|The core dump is saved under the specified directory and named
|Full path with a filename
|The core dump is saved under the specified directory and with the specified filename
Restart the server.
Verify the tool is active¶
MySQL writes to the log when generating a core file and delegates the core dump operation to the Linux kernel. An example of the log message is the following:
Writing a core file
MySQL using the
libcoredumper to generate the file creates the following message in the log:
Writing a core file using lib coredumper
Every core file adds a crash timestamp instead of a PID for the following reasons:
Correlates the core file with a crash. MySQL prints a UTC timestamp on the crash log.
10:02:09 UTC - mysqld got signal 11;
Keeps multiple core files.
For example, the operators and containers run as PID 1. If the process ID identified the core file, each container crash generates a core dump that overwrites the previous core file.
Disable the libcoredumper¶
You can disable the libcoredumper. A core file may contain sensitive data and takes disk space.
To disable the
libcoredumper, do the following:
mysqldsection of my.cnf, remove the
Restart the server.