PHP: Remote MySQL connections very slow

Question

I have two servers, both running CentOS 5.7 and cPanel-CURRENT. One is x86 and the other is x64. Both are using Apache 2.2.21, PHP 5.3.8 and MySQL 5.1.

If I query the local database on any one of the servers, the results are returned instantly. In this instance a few thousand results are being returned. However running the same query from one server to another and the query takes 10+ seconds to complete.

If I use MySQL Workbench 5.2 to query the remote database from my workstation with the same query, it completes in less than a second, which makes me think there's a problem with PHP or something else server-related.

Has anyone else encountered this issue before and know how to resolve it? Any help would be greatly appreciated.

Solution 1

First guess:

It might be a DNS issues and you may use --skip-name-resolve option in my.cnf or you may use only IP addresses in the MySQL grant tables.

Second guess:

It might be a problem with the security level and I suggest to temporarily disable selinux or the firewall and run the test again.

Solution 2

I had this exact issue with a PHP/MySQL application.

Just wanted to share that adding "skip-name-resolve" to my.ini fixed it for me. I was a little confused by this since my application on desktop 1 was accessing desktop 2 (mysql) using IP address. I am going between two Windows 7 desktops.