on 07-16-2018 02:57 AM
We set erasure coding policy to RS-6-3-1024k.
For rack fault-tolerance, it is also important to have at least as many racks as the configured EC stripe width. For EC policy RS (6,3), this means minimally 9 racks, and ideally 10 or 11 to handle planned and unplanned outages. For clusters with fewer racks than the stripe width, HDFS cannot maintain rack fault-tolerance, but will still attempt to spread a striped file across multiple nodes to preserve node-level fault-tolerance.
Supposely, we only have 8 racks how come it doesn't have rack fault-tolerance.
rack1 rack2 rack3 rack4 rack5 rack6 rack7 rack8
cell1 cell2 cell3 cell4 cell5 cell6 cell7 cell8
if the rack1 go down cell1 and cell9 can recovery from the other nodes.
what's the case that it doesn't have rack fault-tolerance.
Thanks in advance.