Look into a dedicated scan executor for notification scans

[keith-turner]

Scanning for notifications is a continuous activity that Fluo does. It may make sense to do one of the following.

• Have a dedicated thread pool for notifcation scans with a small number of threads like Math.max(1,0.10 * numCores)
• Have a prioritizer that gives notification scans a lower priority.

Fluo could offer the prioritizer and/or dispatcher AND utilities or docs to configure them.

[keith-turner]

For prioritization, Fluo could use the built in prioritizer with scan execution hints.