Currently, the Opportunistic Scheduler ignores the node and rack information and allocates strictly on the least loaded node (based on queue length) at the time it received the request. This JIRA is to track changes needed to allow the OpportunisticContainerAllocator to take the node/rack name as hints.
The flow would be:
- If requested node found in the top K leastLoaded nodes, allocate on that node
- Else, allocate on least loaded node on the same rack from the top K least Loaded nodes.
- Else, allocate on least loaded node.