MySQL: Replication and hostname wild cards

Yeah, yeah .. I know, it’s weekend. But I usually can think much better when no one is rattling my cage. So I had another look at my replication problems.

  1. Don’t you never ever change InnoDB settings when migrating between hardware,
    because InnoDB is rather sensitive regarding those parameters.
  2. When you’re setting up the replication (don’t ask me why) and copying over the database to the second replication partner, be aware if you’re using wild cards you’re gonna get seriously bitten in the back.

Now, let’s look at the constellation.


As you can see on the graph above (hah, sometimes Visio is rather useful 😛 ), we do have two MySQL nodes, each serving as master (as in we’re doing “normal” master-master replication).

Here’s what we’re gonna do first:

  1. Setup the user mysql_repl for, granting REPLICATION SLAVE.
  2. Setup the user mysql_slave for and, also granting REPLICATION SLAVE.

Afterwards, we’re gonna copy the mysql database (either via tar and scp, or just via rssh — which is rsync via ssh) to both nodes. Read More