refs #12202 per-tenant QOS enhancement
refs #12202 tweaked the logger init
refs #12202 if the tenant set hasn't changed, keep the existing tenant checker running
refs #12202 changed to mongo client class for db connection
refs #12202 performance tweaks
refs #12202 clean up
refs #12202 clean up
refs #12202 moved completely off the old mongo connection API
refs #12202 query optimization
refs #12202 added comments and commented out some log statements
refs #12202 added more comments
Merge pull request #6 from Elastica/pvt-jk-12202

refs #12202 per-tenant QOS enhancement