MySQL Bugs: #80835: Server crashes on startup with invalid server-id

Bug #80835	Server crashes on startup with invalid server-id
Submitted:	23 Mar 2016 9:40	Modified:	29 Mar 2016 13:19
Reporter:	Cédric Bruderer	Email Updates:
Status:	Not a Bug	Impact on me:	None
Category:	MySQL Server	Severity:	S3 (Non-critical)
Version:	5.6.25	OS:	Ubuntu (14.04)
Assigned to:		CPU Architecture:	Any

Description:
When the server-id is set to an invalid value, the server crashes on startup.

Following you can find the last six lines of the log file:

Unknown suffix 'n' used for variable 'server_id' (value 'no')
2016-03-22 08:55:05 0 [ERROR] /home/mysql/product/mysql-5.6.25-linux-glibc2.5-x86_64/bin/mysqld: Error while setting value 'no' to 'server_id'
2016-03-22 08:55:05 0 [ERROR] Aborting
2016-03-22 08:55:05 0 [Note] Binlog end
160322 08:55:05 mysqld_safe mysqld from pid file /home/mysql/data/dummy/rpi-nfs.pid ended

How to repeat:
1) Set the "server-id" with an invalid value in the my.cnf
2) Start the server

Suggested fix:
- override the invalid value

Isn't it preferable to not startup so that DBA is alerted to a problem with the configuration?  I guess it's a matter of personal choice.

Hi Cédric,

Thank you for the report.
I'm fully agree with my colleague Shane, and this is an expected behavior to avoid any potential consequences hence aborting for the invalid value. Adjusting to the default value is not recommended in this case as if it is a slave and more than one slave have same server_id, it can cause a havoc. For example as noted in Bug #72581.

Also, this issue can be even observed with some of the "essential" parameters where server is aborted :

-- port with invalid value

[umshastr@hod03]/export/umesh/server/binaries/mysql-5.6.29: gdb --args bin/mysqld --port=no  --basedir=/export/umesh/server/binaries/mysql-5.6.29 --datadir=/export/umesh/server/binaries/mysql-5.6.29/80829 --core-file --socket=/tmp/mysql_ushastry.sock   --log-error=/export/umesh/server/binaries/mysql-5.6.29/80829/log.err
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Reading symbols from /export/umesh/server/binaries/mysql-5.6.29/bin/mysqld...done.
(gdb) run
Starting program: /export/umesh/server/binaries/mysql-5.6.29/bin/mysqld --port=no --basedir=/export/umesh/server/binaries/mysql-5.6.29 --datadir=/export/umesh/server/binaries/mysql-5.6.29/80829 --core-file --socket=/tmp/mysql_ushastry.sock --log-error=/export/umesh/server/binaries/mysql-5.6.29/80829/log.err
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
Unknown suffix 'n' used for variable 'port' (value 'no')
2016-03-29 15:17:14 0 [ERROR] /export/umesh/server/binaries/mysql-5.6.29/bin/mysqld: Error while setting value 'no' to 'port'
2016-03-29 15:17:14 0 [ERROR] Aborting

2016-03-29 15:17:14 0 [Note] Binlog end
[Inferior 1 (process 16883) exited with code 01]
Missing separate debuginfos, use: debuginfo-install glibc-2.17-78.0.1.el7.x86_64 libaio-0.3.109-12.el7.x86_64 libgcc-4.8.3-9.el7.x86_64 libstdc++-4.8.3-9.el7.x86_64 nss-softokn-freebl-3.16.2.3-13.el7_1.x86_64
(gdb)

Thanks,
Umesh