Q1: What does the IoT collector run on?
It is a Java application and runs inside a JVM, which can be installed on all mainstream platforms.
Q2: How does the restart via GUI work?
The audit module provides an interface, which sends the restart request to the appropriate receiver. Then it depends on the sensor, whether it provides means to do the restart or not.
Q3: Would load balancer be a single point of failure?
No, e.g. Amazon Load Balancer or another software/hardware load balancers can avoid SPOF.
Q4: What if the load balancer is setup between multiple servers? How will the load balancing work?
Depends on the load balancing mode - it may be based on IP ranges, traffic etc. All modules (receivers, senders, and audits) are visible to each other (auto-discovery).