-Intelligence of decommission
Allen Wittenauer 2009-08-28, 20:07
As I sit here and wait for node decommission to finish, I was wondering
about the intelligence of the decision making. [The name nodes, not mine.
Let's say I have the following scenario:
I have two files. Both files consist of one block with a replication factor
of three. I decommission two nodes. File #1 has two of its replicas on the
two nodes I am decommissioning. File #2 has only one of its replicas on one
of the two nodes I am decommissioning.
Is the block with two replicas on the two nodes I am decommissioning given
priority? How does the name node decide which blocks to re-replicate first?