Here is my problem. I have a busy Drupal site struggling under high load. After applying all caches I see that, no surprisingly, database is the bottleneck. I have two servers to handle the site: A and B, on the same rack/subnet. The server A is frontend web server and is set to handles all database queries to the server B. Currently there is no detabase set up on A. The database on B is MariaDB 10. CPU-wise, The server A is much less powerful than B, but has the same amount of RAM. The load on server A is very low (< 0.5) The load on server B is not low (> 5)
So my questions are:
-Are there any benefit in defining master/slave database on these two servers?
-If is good idea to go master/slave route, how do you arrange the servers? (which server should be the master? Which one should be the frontend?)