I recently upgraded my main box (main out of 8 servers) to new hardware. I found out some interesting things by doing so. I thought maybe the few revelations I had might help others.
-Load on your main server goes up as you add elements even if they are monitored by other pollers-
I found the hard way that load increases on your main box as you add elements and even other pollers. You would think adding additional pollers would take a lot of heat off your main which (which it does) but the workload will still increase.
-An overworked main box can cause any number or type of issues-
I have a large install and for months I have been chasing many small issues; a poller down here, a missed alert there, why is that graph frozen, why are my numbers off etc etc. I actually got to the point on my old main server where it would for no reason just stop processing everything even though all services were up and would have to reboot it and all the other pollers to get functionality back. Once I upgraded all the issues stopped dead. I have not had to troubleshoot a strange issue or reboot it or a poller since.
-Summary (my humble user opinion)-
Your main box is the most important server in your installation (SQL would be a close second). It obviously is relied on (at different levels) by all your other servers and is responsible for far more than just being on of your pollers. If ignored or not maintained, or if allowed to be overworked your install can suffer any manner of errors, phantom problems, real problems and lord knows what else.
