Q: Is there a need to have the Event service on a different server than the engine?
A: No.
Details:
No there is not an appreciable benefit by separating the two. Only a small benifit is gained if installing on a DC holding the global catalog.
Q: Is there any loss of events if for some reason the Event service is offline?
A: Yes.
Details:
Yes and No! Since we have a "Partial Replica", when the Event Service comes back on-line, we will poll for delta changes and create events accordingly. The "NO" part of the answer is relevant because if you have multiple events for the same object of the same type, we will only see the "net" change. Ie.. If the Event Service is stopped, and you rename BOB to BOB1, then BOB2, then BOB3; when the Event Service comes back up, we will rename BOB to BOB3.
Q: If the Engine service is offline what happens to changes in AD that occur during down time?
A: Events will continue to be cached at the Event Service and sent to the Engine Service once it is operational again
Details:
If Engine service is stopped, then ALL events will QUEUE up persistently until the Engine Service is restored.
Q: Is there a design that has a failover situation for the Engine and or the Event service?
A: No.
Details:
In this release there is no ability to "cluster" or have failover solutions for either the engine or event services. There are plans on that functionality in the future. You can have multiple Event Servers installed, and they will build and keep their partial replica up to date, but they cannot be "authorized" to the engine at the same time. If the primary event service went away, you could authorize one of the secondary's. (Not really necessary) Best practice if you had a catastrophe, would be to install the Event Service on another server, then restore the partial replica (DATA directory) from tape to preserve the state of your objects. The data directory is at C:\ProgramData\Condrey Corporation\File System Factory\Event\Data.
Q: Can you have multiple Event Services per Domain?
A: No.
Details:
NO, for a couple of reasons. We do not have the need to have multiple event services running because we maintain our own partial replica, and we do not have any code in the Event Service that detects duplicates.
Q: What if the event service is on a DC? Does it still have the partial replica?
A: Yes.
Details:
Yes, everywhere an Event service is installed, a partial replica gets created and maintained.