I have this error when I try to connect to database using PHP:
mysql_connect(): Headers and client library minor version mismatch. Headers:50147 Library:50501

And this warning in phpmyadmin:
Your PHP MySQL library version 5.5.1-m2 differs from your MySQL server version 5.1.54. This may cause unpredictable behavior.

Packages installed:


PHP version:PHP 5.3.3
MySQL: mysql Ver 14.14 Distrib 5.1.54
OS: Amazon AMI 64bit

I tried to remove php and install again, but no success.

2 Answers 2


Changed type of database connection in vbulletin config from mysql to mysqli and problem solved.


Looks like your SQL shared compat libraries are a version behind the client and the server, as the error message states this can result in some funny behaviour.

Try upgrading the package Percona-SQL-shared-compat-5.1.43-2.x86_64 to Percona-SQL-shared-compat-5.1.54-2-rel12.5.188.rhel5.x86_64, it should be available from the same package repo where you upgraded the rest of your installation from.

  • Thanks. Version in repo really differs from that one on site: percona.com/downloads/Percona-Server-5.1/…
    – NARKOZ
    Jan 29, 2011 at 16:12
  • No problem, just as reminder, it's always best to keep the versions for both your libraries and client the same, the server version is not so dependant (but I'm a bit ADD so I keep it in the same ver as well)
    – lynxman
    Jan 29, 2011 at 16:14
  • I removed the old one and installed all over again with same versions. Looks like problem with php, because the result is the same.
    – NARKOZ
    Jan 29, 2011 at 16:39
  • Yeah I just saw that... normally I ignore that alert if and only if the MySQL library PHP was compiled in is older than the server version, in that case it should be fine
    – lynxman
    Jan 29, 2011 at 17:27

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