1

I've got two mysql servers, A and B which are currently set up in a circular, MASTER MASTER replication scheme. I need to add third server to the mix, C as a SLAVE to B as pictured below:

A <---> B
        |
        v
        C

I just made an attempt at doing this, but I forgot to take into account the fact that writes that go from A to B will not make it to C without turning on log-slave-updates on B being turned on.

My question: if I turn log-slave-updates on for B, isn't A going to pick up on those log entries again execute them a second time, thereby spawning some sort of black hole that could threaten to swallow the planet?

0

As long as the values of server-id are different for each server, no planets will be swallowed. Not even Pluto.

I suggest you turn on binlog and log_slave_updates on all servers. Then rebuild C from B (as, I assume, you did once). Then proceed. I would not want to try to do it from the current C, which is missing stuff.

1
  • Enabled log_slave_updates on all servers and rebuilt C from B as recommended. All is good now, crisis averted. Thanks! – ediv Sep 13 '17 at 17:44

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.