MySQL Bugs: #79229: mysql-5.7.9: included systemd service fails to start

Bug #79229	mysql-5.7.9: included systemd service fails to start
Submitted:	11 Nov 2015 14:04	Modified:	11 Nov 2015 19:44
Reporter:	Timo Gurr	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server: Packaging	Severity:	S3 (Non-critical)
Version:	5.7.9	OS:	Linux
Assigned to:		CPU Architecture:	Any

Description:
Running systemctl start mysqld I get:

Nov 11 14:30:36 lxhost mysqld[2458]: 2015-11-11T13:30:36.629259Z 0 [Warning] CA certificate ca.pem is self signed.
Nov 11 14:30:36 lxhost mysqld[2458]: 2015-11-11T13:30:36.629292Z 0 [Note] Skipping generation of RSA key pair as key files are present in data directory.
Nov 11 14:30:36 lxhost mysqld[2458]: 2015-11-11T13:30:36.629793Z 0 [Note] Server hostname (bind-address): '*'; port: 3306
Nov 11 14:30:36 lxhost mysqld[2458]: 2015-11-11T13:30:36.629821Z 0 [Note] IPv6 is available.
Nov 11 14:30:36 lxhost mysqld[2458]: 2015-11-11T13:30:36.629828Z 0 [Note]   - '::' resolves to '::';
Nov 11 14:30:36 lxhost mysqld[2458]: 2015-11-11T13:30:36.629834Z 0 [Note] Server socket created on IP: '::'.
Nov 11 14:30:36 lxhost mysqld[2458]: 2015-11-11T13:30:36.636377Z 0 [Note] Event Scheduler: Loaded 0 events
Nov 11 14:30:36 lxhost mysqld[2458]: 2015-11-11T13:30:36.636676Z 0 [Note] /usr/x86_64-pc-linux-gnu/bin/mysqld: ready for connections.
Nov 11 14:30:36 lxhost mysqld[2458]: Version: '5.7.9'  socket: '/run/mysqld/mysqld.sock'  port: 3306  Exherbo
Nov 11 14:30:36 lxhost systemd[1]: mysqld.service: PID file /run/mysqld/mysqld.pid not readable (yet?) after start: No such file or directory

Having a look in the service file /usr/x86_64-pc-linux-gnu/lib/systemd/system/mysqld.service there's a line:

PIDFile=/run/mysqld/mysqld.pid

which probably is for systemd itself and not used by mysqld. After adding --pid-file=/run/mysqld/mysqld.pid to the ExecStart in the mysqld.service file:

# Start main service
ExecStart=/usr/x86_64-pc-linux-gnu/bin/mysqld --daemonize $MYSQLD_OPTS --pid-file=/run/mysqld/mysqld.pid

systemctl start mysqld is working fine:

Nov 11 14:31:48 lxhost mysqld[2536]: 2015-11-11T13:31:48.007535Z 0 [Note] /usr/x86_64-pc-linux-gnu/bin/mysqld: ready for connections.
Nov 11 14:31:48 lxhost mysqld[2536]: Version: '5.7.9'  socket: '/run/mysqld/mysqld.sock'  port: 3306  Exherbo
Nov 11 14:31:48 lxhost systemd[1]: Started MySQL Server.

How to repeat:
1. compile from sources
2. install
3. try to start mysql via the provided systemd service

Suggested fix:
Could you introduce a compile time option like e.g. -DMYSQL_PIDFILE:STRING=/run/mysqld/mysqld.pid to set a default for the pidfile just like it is already in place for other things like e.g. datadir (-DMYSQL_DATADIR:PATH=/var/lib/mysql)?

And/Or add --pid-file=@SYSTEMD_PID_DIR@/mysqld.pid to ExecStart in the mysqld.service.in file in the sources?

possible fix/workaround

Attachment: mysql-5.7.9-bug79229.patch (text/x-patch), 770 bytes.

Hi!

Thanks for your report.

We have discovered the same issue and applied the same fix, it will be
part of the next release.

Noted in 5.7.10, 5.8.0 changelogs.

The systemd unit file did not specify any --pidfile option for
mysqld, with the result that server startup could fail. The unit file
now includes a default --pidfile option in the ExecStart value. This
default can be overridden in the override.conf file by changing both
PIDFile and ExecStart to specify the PID file path name.

Documentation updated:

 https://dev.mysql.com/doc/refman/5.7/en/server-management-using-systemd.html