[Sqlrelay-discussion] mysql proxy

[Nick W. <woo...@ho...>]

Hi All,

I am trying to setup SQL Relay to behave as an effective proxy for MySQL 
requests on any MySQL database.  I would like any person connecting to any 
database through mysql locally (192.168.51) through mysql.sock to connect 
out through SQL Relay to one of two back end servers - two nodes on a MySQL 
cluster (192.168.1.54 and 192.168.1.53).

I have setup SQLRelay with a configuration as described below:

<?xml version="1.0"?>
<!DOCTYPE instances SYSTEM "sqlrelay.dtd">
<instances>
        <instance id="defaultid" port="3306" 
socket="/var/lib/mysql/mysql.sock" connections="1" maxconnections="6" 
dbase="mysql" maxqueuelength="0" growby="1" ttl="60" endofsession="commit" 
sessiontimeout="600" runasuser="nobody" runasgroup="nobody" cursors="5" 
authtier="database" handoff="pass">
                <users>
                </users>
                <connections>
                       <connection connectionid="kudos-file-linux-two" 
string="db=mysqlclustertest;user=root;password=XXXXXXXX;host=192.168.1.53;port=3306;" 
metric="1" behindloadbalancer="no" />
                <connection connectionid="kudos-file-linux-two" 
string="db=mysqlclustertest;user=root;password=XXXXXXXX;host=192.168.1.53;port=3306;" 
metric="1" behindloadbalancer="no" />
                </connections>
        </instance>

</instances>


I am having a few problems with this.  SQL relay seems to be mainly geared 
for connection to an individual database - is this correct?  With that in 
mind, i don't really want to specify a database in the connection string, 
but on reading the documentation there seems no other way.

I would really like for it to be able to connect to any database that is 
requested by the user through on the mysql proxy and for that to go off to 
the cluster.  (the authtier=database setting i presume would sort out any 
user being able to connect?)

Also, if i want to configure my proxy server to talk out using SQL Relay 
with the drop in libraries with PHP and Apache - is it just a case of 
modifying the /etc/init.d/httpd start up script with the LD_PRELOAD 
statement - or is it more complicated than this?

Any problems anyone can see with my configuration or ideas, please let me 
know!  I know someone has achieved what i am after ... but just not quite 
sure how they managed it!

Thanks,

Nick