Adjust multi-threading from defaults depending on lease-database choice
Different lease database types (memfile persist, mysql, postgresql) have wildly different thread pool and packet queue optimal settings. See here for details.
I propose to do the following:
- memfile (no persist) - do not change anything
- memfile (persist) - add multi-threading section with appropriate thread pool and packet queue size settings.
- mysql - add multi-threading section with appropriate thread pool and packet queue size settings.
- postgresql - add multi-threading section with appropriate thread pool and packet queue size settings.
Each of those has different optimal values (though it may vary some by CPU / RAM configuration as well but these get you in the ballpark).