Multiple Collectors

There are several reasons why you would want multiple collectors in an environment:

• High Availability: If a collector system fails you can have another one take it over (LM supports active-active). Also useful for collector upgrades without downtime
• Load: Depending on how many items (not just devices) your monitoring, you may need many collectors to handle the load.
• Site: Some site-to-site VPN are not stable enough for monitoring remotely over and there can be a major side-effect mentioned below.
• Network Segmentation: The collector and it's failover collectors needs to be able to directly communicate with each resource being monitored, so network segmentation may require multiple collectors. (Guess that also depends on your definition of "environment").

I don't think it really matter if you setup a virtual machine or use physical boxes. I think that would depend on your infrastructure. Most of ours are virtual without problems.

A big possible problem to keep in mind about remote monitoring is due to LM's current lack of full dependencies. If a site that goes down that is being monitored by a remote collector will cause an alert for every resource at that site. Without the collector also going down, it will not cause a Collector Down condition and will not prevent the those alerts from occurring. So I avoid doing remote monitoring (on the Resource tab) whenever possible personally.