* Redwood files now growth in large page chunks controlled by a knob to reduce truncate() calls for expansion. PriorityMultiLock has limit on consecutive same-priority lock release. Increased Redwood max priority level to 3 for more separation at higher BTree levels.
* Simulation fix, don't mark certain IO timeout errors as injected unless the simulated process has been set to have an unreliable disk.
* Pager writes now truncate gradually upward, one chunk at a time, in response to writes, which wait on only the necessary truncate operations. Increased buggified chunk size because truncate can be very slow in simulation.
* In simulation, ioTimeoutError() and ioDegradedOrTimeoutError() will wait until at least the target timeout interval past the point when simulation is sped up.
* PriorityMultiLock::toString() prints more info and is now public.
* Added queued time to PriorityMultiLock.
* Bug fix to handle when speedUpSimulation changes later than the configured time.
* Refactored mutation application in leaf nodes to do fewer comparisons and do in place value updates if the new value is the same size as the old value.
* Renamed updatingInPlace to updatingDeltaTree for clarity. Inlined switchToLinearMerge() since it is only used in one place.
* Updated extendToCover to be more clear by passing in the old extension future as a parameter. Fixed initialization warning.
Move the argument for the number of servers per pod into a command-line argument so we can use the same config file at different storage server densities.
* Trigger buildTeam operation if server transition from unhealthy -> healthy
DataDistribution actor helps in building teams as server count changes
(add/removal), however, it is possible that total_healthy_server count
is insufficient to allow team formation. If happens, even healthy server
count recover, the buildTeam operation will not be triggered.
Patch proposal is to trigger `checkBuildTeam` operation if server
transitions from unhealthy -> healthy state. Incase system already
has created enough teams (desiredTeamCount/maxTeamCount), the operation
incurs a very minimal cost.
Evan Tschannen