Yes. Set up master-master replication (don't forget log_slave_updates, etc.), then change mmm config and finally restart agents/monitor.
When I try to start the agent these messages are repeatedly logged:
2009/10/30 20:08:59 FATAL Child exited with exitcode 99, restarting 2009/10/30 20:08:59 FATAL Listener: Can't create socket!
→ For some reason the agent tries to listen on an IP that is not configured on the host. Check your configuration and be sure that you have not mistyped anything. Be sure to also check the this configuration directive.
Yes, you can run multiple instances of mmm_mond on the same host. You have to copy the init-script and adjust the 'CLUSTER' variable (e.g. CLUSTER='C1'). The config file for this second instance should be named mmm_mon_C1.conf instead of mmm_mon.conf. You also have to adjust some things in the
<monitor> section of the config (choose a unique port number, default is 9988):
pid_path /var/run/mmmd_mon_C1.pid port 9990
To control this cluster you can use
mmm_control @C1 - e.g.:
mmm_control @C1 show
When you eat something tasty, you say: “Mmm…”. Sometimes “Mmmmmmm”… or “HmMMmmmmm” - but we decided to go with just simply MMM. (from #mmm on freenode)