Currently, turning off the balancer doesn't turn off auto-splitting, which has caused confusion in the field, because customers continue to observe metadata refreshes. For better customer experience we should also turn off auto-splitting, when the balancer is turned off.
Since it almost never makes sense for the balancer to be on, but the auto-splitter to be off, I propose the following behaviour change of the balancerStart / balancerStop commands:
- balancerStop - both stops the balancer and sets the auto-splitter setting to false
- balancerStart - both starts the balancer and sets the auto-splitter setting to true
As a result, start/stop of the balancer will completely forget what was the previous auto-splitter setting.
Customers who wish to run balancer off/auto-splitter on or vice-versa configurations, will have to do it through direct writes to config.settings.