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Last tested: Jun 18, 2019
--scheduler-threads=<i> is a good idea if you would like to limit the amount of schedules that are processed at one time, and the rest would be queued up. So if you just want to decrease the amount that would execute at one time down from 3 (default threads) that would be a good way to change that.
As of version 6.18, the unlimited pool is set separately from the above via the
--unlimited-scheduler-threads=<i> flag. In previous versions
--unlimited-scheduler-threads was ignored and the pool was set to the same number of threads as
scheduler-query-limit=<i> flag (default: 10) : If a dashboard that has 20 tiles on it is scheduled, 10 would be queued.
*Note that this limit is PER node, so in the first flags case, if there are 10 nodes, then there would be 30 threads available, etc.