MySQL 5 Master-Master question

Discussion in 'Server Operation' started by tfunky, Jan 4, 2008.

  1. tfunky

    tfunky New Member

    Hi All,

    I'm confused on Master-Master replication vs. a MySql HA cluster...

    Specifically the HA Mysql Cluster Howto and the Mysql5 Master-Master replication on Etch howto.

    I've googled around looking for a definitive anwser on which way to go and I'm not finding anything really concreate other than saying that "In some instances, a HA cluster is the perfect solution, but in most other Master-Master replication is the way to go"

    What??? That's just about as clear as mud!

    I currently have 1 mysql server running and would like to be able to add capacity and redundancy.

    In the past I did the MySQL HA Cluster howto with the 2 loadbalancers, etc, but I somehow managed to smoke the database, so I went back to one system.

    I have multiple webservers behind loadbalancers, and the database server supports those servers.

    With all of that basic questions are:
    1. I'm hoping for a definitive direction on Master-Master replication vs HA Cluster'
    2. With a Master-Master replication, do you still need the loadbalancers?
    3. With Master-Master replication do you have a VIP or does each webserver just point to one database server?

    What is the best/easiest to maintain way of getting a scalable and fault tolerant MYsql setup?


  2. falko

    falko Super Moderator Howtoforge Staff Moderator HowtoForge Supporter ISPConfig Developer

    I recommend Master-Master replication because it's easier to set up and maintain. The big disadvantage with a MySQL cluster (at least for MySQL 5.0) is that all data is held in the memory. So if there's a power failure, all your data is gone.

    You can let each web server point to one database server. :)
  3. tfunky

    tfunky New Member

    Excellent! Whooohooo!

    Would you recommend using a load balancer/VIP incase there is a failure?

    In my head, if each webserver points to 1 database server, then if one of the database servers fails, the LoadBalancers for the website won't know it, and will keep sending people to a "good" webserver, that has a broken backend.

    What do you think is best?
  4. falko

    falko Super Moderator Howtoforge Staff Moderator HowtoForge Supporter ISPConfig Developer

    You could put the webserver and MySQL server on the same node. So if a node goes down, both the webserver and the MySQL server are down, so that all requests will be sent to the healthy node. :)

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