Server doesn't start after yum update

[Aleksandr Kuzminsky]

Successful "yum update" from 5.6.20-rel68.0.el6.x86_64 to 5.6.21-rel69.0.el6.x86_64 stops MySQL but doesn't start it.

db-02: Running transaction check
db-02: Running transaction test
db-02: Transaction test succeeded
db-02: Running transaction
db-02: Updating : Percona-Server-shared-56-5.6.21-rel69.0.el6.x86_64 1/6
db-02: Updating : Percona-Server-client-56-5.6.21-rel69.0.el6.x86_64 2/6
db-02: ls: cannot access /var/lib/mysql//*.err: No such file or directory
db-02: ls: cannot access /var/lib/mysql//*.err: No such file or directory
db-02: Giving mysqld 5 seconds to exit nicely
db-02: Updating : Percona-Server-server-56-5.6.21-rel69.0.el6.x86_64 3/6
db-02: Percona Server is distributed with several useful UDF (User Defined Function) from Percona Toolkit.
db-02: Run the following commands to create these functions:
db-02: mysql -e "CREATE FUNCTION fnv1a_64 RETURNS INTEGER SONAME 'libfnv1a_udf.so'"
db-02: mysql -e "CREATE FUNCTION fnv_64 RETURNS INTEGER SONAME 'libfnv_udf.so'"
db-02: mysql -e "CREATE FUNCTION murmur_hash RETURNS INTEGER SONAME 'libmurmur_udf.so'"
db-02: See http://www.percona.com/doc/percona-server/5.6/management/udf_percona_toolkit.html for more details
db-02: Cleanup : Percona-Server-server-56-5.6.20-rel68.0.el6.x86_64 4/6
db-02: Cleanup : Percona-Server-client-56-5.6.20-rel68.0.el6.x86_64 5/6
db-02: Cleanup : Percona-Server-shared-56-5.6.20-rel68.0.el6.x86_64 6/6
db-02: Verifying : Percona-Server-client-56-5.6.21-rel69.0.el6.x86_64 1/6
db-02: Verifying : Percona-Server-server-56-5.6.21-rel69.0.el6.x86_64 2/6
db-02: Verifying : Percona-Server-shared-56-5.6.21-rel69.0.el6.x86_64 3/6
db-02: Verifying : Percona-Server-server-56-5.6.20-rel68.0.el6.x86_64 4/6
db-02: Verifying : Percona-Server-shared-56-5.6.20-rel68.0.el6.x86_64 5/6
db-02: Verifying : Percona-Server-client-56-5.6.20-rel68.0.el6.x86_64 6/6
db-02:
db-02: Updated:
db-02: Percona-Server-client-56.x86_64 0:5.6.21-rel69.0.el6
db-02: Percona-Server-server-56.x86_64 0:5.6.21-rel69.0.el6
db-02: Percona-Server-shared-56.x86_64 0:5.6.21-rel69.0.el6
db-02:
db-02: Complete!

[Valerii Kravchuk (valerii-kravchuk)]

This is easy to confirm:

...
Updated:
  Percona-Server-client-56.x86_64 0:5.6.21-rel69.0.el6
  Percona-Server-devel-56.x86_64 0:5.6.21-rel69.0.el6
  Percona-Server-server-56.x86_64 0:5.6.21-rel69.0.el6
  Percona-Server-shared-56.x86_64 0:5.6.21-rel69.0.el6
  bash.x86_64 0:4.1.2-15.el6_5.2
  libcgroup.x86_64 0:0.40.rc1-6.el6_5.1
  nss.x86_64 0:3.16.1-7.el6_5
  nss-softokn.x86_64 0:3.14.3-12.el6_5
  nss-softokn-freebl.x86_64 0:3.14.3-12.el6_5
  nss-sysinit.x86_64 0:3.16.1-7.el6_5
  nss-tools.x86_64 0:3.16.1-7.el6_5
  nss-util.x86_64 0:3.16.1-2.el6_5
  percona-toolkit.noarch 0:2.2.11-1
  percona-xtrabackup.x86_64 0:2.2.5-5027.el6
  php.x86_64 0:5.3.3-27.el6_5.2
  php-cli.x86_64 0:5.3.3-27.el6_5.2
  php-common.x86_64 0:5.3.3-27.el6_5.2
  php-mysql.x86_64 0:5.3.3-27.el6_5.2
  php-pdo.x86_64 0:5.3.3-27.el6_5.2
  tzdata.noarch 0:2014h-1.el6

Complete!
[root@centos openxs]# mysql -uroot -e 'select version()';
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)
[root@centos openxs]# ps aux | grep mysqld
root 1884 0.0 0.0 103244 868 pts/0 S+ 09:56 0:00 grep mysqld
[root@centos openxs]# service mysql start
Starting MySQL (Percona Server)..... SUCCESS!
[root@centos openxs]# mysql -uroot -e 'select version()';
+-------------+
| version() |
+-------------+
| 5.6.21-69.0 |
+-------------+

Probably it's even intentional, but i do not see this clearly documented.

[Tomislav Plavcic (tplavcic)]

I think this has been fixed with the work on bugs (available in releases 5.6.22 and 5.6.23):
https://bugs.launchpad.net/percona-server/+bug/1311840
https://bugs.launchpad.net/percona-server/+bug/1201896

So I will mark it as duplicate of the first one, if this turns out to be an issue still active then please make a comment and reopen the bug with more info.