The Server Agent and the OnSight vCollector perform two separate functions. This article will outline the purpose of each, and then explain how they interact and what the benefit is of using both.
The Server Agent installs directly on your server (whether virtual or bare metal) and provides host level resource utilization and application specific metrics. The Server Agent gives you details like CPU, memory, disk space utilization, bandwidth, etc and also allows you to monitor processes and services. We also have a number of plugins available to monitor applications like web servers, databases, caches, and so on.
This is critical information for identifying the source of incidents, because you can review the activity on the host before and while the outage was happening.
The OnSight vCollector functions the same as one of our public monitoring probes, running uptime checks and synthetic monitoring against your publicly available servers and web endpoints, but the Onsight vCollector sits behind your firewall and monitors on your private network. The OnSight can run uptime and synthetic checks on your servers behind the firewall, monitoring services like HTTP/HTTPS, RDP, database connectivity, and port availability.
OnSight can also function as a proxy for servers that have the Server Agent installed, but no connection to the outside internet. OnSight can also monitor network devices with SNMP polling and receive SNMP Traps.
You don’t need to use OnSight to use the Agent, or vice versa, but using both gives you a more full view of your infrastructure with the different kinds of monitoring each offers.