This was meant to be used as a signal that the estimation
did consider all of the pods, but x13n pointed out that
other k8s primitives may also limit it so the best option
is to compare a list of estimated pods.
The binpacking algorithm is O(#pending_pods * #new_nodes) and
calculating a very large scale-up can get stuck for minutes or even
hours, leading to CA failing it's healthcheck and going down.
The new limiting prevents this scenario by stopping binpacking after
reaching specified threshold. Any pods that remain pending as a result
of shorter binpacking will be processed next autoscaler loop.
The thresholds used can be controlled with newly introduced flags:
--max-nodes-per-scaleup and --max-nodegroup-binpacking-duration. The
limiting can be disabled by setting both flags to 0 (not recommended,
especially for --max-nodegroup-binpacking-duration).
Daniel Gutowski
Maciek Pytel