Mysql + PHP : force hostname and disable unix socket

[PAGES Vincent]

Hi,

I hope i'm writing in the good mailing list...

Since one year, i'm working on loadbalancing solution for  webservers 
(usually Apache 2). Behind a cluster of http servers, we  can find a 
mysql cluster.
Generally ppl are using the mysql_connect with the hostname =  
"localhost". When i suggest a loadbalancing solution, the mysql  
database is hosted on a different server. So webpages of all  virtual 
hosts need to be updated to connect on the new hostname;  which can be 
very annoying.

I've patched PHP, and added 2 variables in PHP.ini which are :
   mysql.unix_socket = On|Off
   mysql.force_host =

The first one can disabled the connection on mysql unix socket and  
transform "localhost" in "127.0.0.1". This allows to redirect mysql  
traffic with iptables. Like :
    iptables -t nat -A PREROUTING -p tcp --dport 3306 -d 127.0.0.1 -j 
DNAT --to-destination <ip cluster>

The second force mysql_connect to one database whatever the  hostname 
specified in the mysql_connect function. This setting can be configured 
for all or just for one virtual host.

I've already posted on php internal mailing list. Some ppl seems to be 
interested.
I think it can be someting helpful for System Administrators. Tell  me 
ur feelings about this. If u think that's something good, then we may 
apply these changes to mysql extension.

PAGES Vincent
System Administrator
France