Comment 8 for bug 1311840

The problem is valid for 5.5 and needs to be fixed.

# rpm -qa | grep Percona
Percona-Server-shared-compat-5.5.35-rel33.0.611.rhel6.x86_64
Percona-Server-client-55-5.5.39-rel36.0.el6.x86_64
Percona-Server-server-55-5.5.39-rel36.0.el6.x86_64
Percona-Server-shared-55-5.5.39-rel36.0.el6.x86_64
Percona-Server-devel-55-5.5.39-rel36.0.el6.x86_64

Here is an excerpt from the yum update output

Downloading Packages:
(1/4): Percona-Server-client-55-5.5.40-rel36.1.el6.x86_6 | 5.9 MB 00:00
(2/4): Percona-Server-devel-55-5.5.40-rel36.1.el6.x86_64 | 946 kB 00:00
(3/4): Percona-Server-server-55-5.5.40-rel36.1.el6.x86_6 | 15 MB 00:00
(4/4): Percona-Server-shared-55-5.5.40-rel36.1.el6.x86_6 | 648 kB 00:00
--------------------------------------------------------------------------------
Total 46 MB/s | 23 MB 00:00
Running rpm_check_debug
Running Transaction Test
Transaction Test Succeeded
Running Transaction
  Updating : Percona-Server-shared-55-5.5.40-rel36.1.el6.x86_64 1/8
  Updating : Percona-Server-client-55-5.5.40-rel36.1.el6.x86_64 2/8
  Updating : Percona-Server-server-55-5.5.40-rel36.1.el6.x86_64 3/8
ls: cannot access /opt/mysql/dbdata1/reference-p0/*.err: No such file or directory
ls: cannot access /opt/mysql/dbdata1/reference-p0/*.err: No such file or directory
Giving mysqld 5 seconds to exit nicely
Percona Server is distributed with several useful UDF (User Defined Function) from Percona Toolkit.
Run the following commands to create these functions:
mysql -e "CREATE FUNCTION fnv1a_64 RETURNS INTEGER SONAME 'libfnv1a_udf.so'"
mysql -e "CREATE FUNCTION fnv_64 RETURNS INTEGER SONAME 'libfnv_udf.so'"
mysql -e "CREATE FUNCTION murmur_hash RETURNS INTEGER SONAME 'libmurmur_udf.so'"
See http://www.percona.com/doc/percona-server/5.5/management/udf_percona_toolkit.html for more details
  Updating : Percona-Server-devel-55-5.5.40-rel36.1.el6.x86_64 4/8
  Cleanup : Percona-Server-devel-55-5.5.39-rel36.0.el6.x86_64 5/8
  Cleanup : Percona-Server-server-55-5.5.39-rel36.0.el6.x86_64 6/8
  Cleanup : Percona-Server-client-55-5.5.39-rel36.0.el6.x86_64 7/8
  Cleanup : Percona-Server-shared-55-5.5.39-rel36.0.el6.x86_64 8/8
  Verifying : Percona-Server-devel-55-5.5.40-rel36.1.el6.x86_64 1/8
  Verifying : Percona-Server-server-55-5.5.40-rel36.1.el6.x86_64 2/8
  Verifying : Percona-Server-shared-55-5.5.40-rel36.1.el6.x86_64 3/8
  Verifying : Percona-Server-client-55-5.5.40-rel36.1.el6.x86_64 4/8
  Verifying : Percona-Server-client-55-5.5.39-rel36.0.el6.x86_64 5/8
  Verifying : Percona-Server-devel-55-5.5.39-rel36.0.el6.x86_64 6/8
  Verifying : Percona-Server-shared-55-5.5.39-rel36.0.el6.x86_64 7/8
  Verifying : Percona-Server-server-55-5.5.39-rel36.0.el6.x86_64 8/8

Updated:
  Percona-Server-client-55.x86_64 0:5.5.40-rel36.1.el6
  Percona-Server-devel-55.x86_64 0:5.5.40-rel36.1.el6
  Percona-Server-server-55.x86_64 0:5.5.40-rel36.1.el6
  Percona-Server-shared-55.x86_64 0:5.5.40-rel36.1.el6

Complete!

# mysql
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/opt/mysql/dbprod/reference-p0.sock' (2)
[root@mirror ~]# service mysql restart
MySQL (Percona Server) PID file could not be found! [FAILED]
Starting MySQL (Percona Server)........... [ OK ]