No Collection (Collect Never)

The NEVER collection mode enables a Service to submit tasks and not collect them. Such a Service, for example, writes results to a database. Services created with NEVER collection can only submit and update. Calls to execute throw an Exception. This collection mode is not available when using a Service proxy. To create a NEVER collection Service, set the CollectionType option to NEVER.

Calling destroy releases resources locally on the Driver, and indicates that the Instance is finished with submission. If the Driver is shut down and times out, the session is considered to be done submitting, just as if the Driver called destroy. After the session finishes submitting due to one of the two prior events, and all tasks complete or fail, the session automatically closes.

No Collection Failover

There are no special issues with failover on No Collection Services, and as many Brokers as you want can be used to recover any running Services. You would, however, need to ensure that any database to which you are sending results has its own failover or redundancy configuration in case of failure.