I have a dedicated server that hosts about 70 domains… some are just plain php static websites, others are wordpress websites and a few others are on ruby on rails.
In the past few days I have experienced very slow queries on mysql server…
Queries like:
SELECT * FROM users WHERE id = 5
takes 1.8 secs…
I enabled the slow queries log and found that all the wordpress sites dont have their databases indexed… i dont know if this is the cause of my problem…..
So the question is should i install different mysql servers for wordpress websites and ruby based websites? Or just a little tunning to the my.cnf file will do?
Well considering that you are not augmenting the hardware. I belive installing instance servers or even installing Virtual servers would not help you. You should really try tuning the databases and adding valuable indicies where necessary.