Availability This tool is in tech preview.
This feature was implemented in Percona Server for MySQL 8.0.21-12 and has been tested against the version’s supported platforms. The tool may not be supported on future platforms. You should test before putting this tool into production.
A core dump file is the documented moment of a computer when either the computer or an application exits. 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
enhanced to work on newer Linux versions, and GCC and CLANG.
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
The variable can have the following possible values:
|Blank||The core dump is saved under MySQL datadir and named core.|
|A path ending with /||The core dump is saved under the specified directory and named core.|
|Full path with a filename||The core dump is saved under the specified directory and filename|
Restart the server.
libcoredumper 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 the crash. MySQL prints a UTC timestamp on the crash log.
10:02:09 UTC - mysqld got signal 11;
Stores multiple core files.
For example, operators and containers run as the process id of PID 1. If the process ID is used to identify the core file, each container crash generates a core dump that overwrites the previous core file.
Disabling the libcoredumper¶
You can disable the libcoredumper. A core file may contain sensitive data and takes disk space.
To disable the
libcoredumper you must do the following:
mysqldsection of my.cnf, remove the
Restart the server.