Hey All, Two questions about the MR2 scheduler code, for anyone more familiar.
- The return type of allocate() suggests that the AM will get some instantaneous allocation of resources. Reading through the two current schedulers, however, it looks like containers are only allocated after Node heartbeats, and that allocate() will rarely return any useful allocation. Is that correct or am I missing something? - The SchedulerNode class maintains state for both a single "reserved" container and several "allocated" containers. As far as I can tell only the capacity scheduler uses the former, but it's not clear to me what the reserved container is for. Is this to enforce hard limits on allocation reserved for particular users? - Patrick
