Affects Version/s: 0.17.0
Fix Version/s: 0.18.0
The block report processing during the startup period should be optimized.
As noted in
HADOOP-3022 during cluster startup all blocks are under-replicated
because they have not been reported by name-nodes yet.
Currently, we routinely move blocks to the neededReplications queue when they
are first reported and then remove them from the list when other nodes report it.
In ideal situation we end up adding all blocks into neededReplications queue first
only in order to remove all of them in the end.