I will be running a cluster with 100-200 nodes, most of which will be shut down at night. For the sake of example lets say that 4 'reliable slaves' will remain turned on continuously, and let me call the rest 'unreliable slaves'.
Storage wise, how would I go about this (using HDFS)? I figure that it would be a bad idea to put persistent data on the unreliable slaves, since turning ~100 computers of simultaneously might wreck havoc to the hdfs(?). So the idea would be to let persistent data only reside on reliable slaves. Would setting dfs.datanode.du.pct=0 on the unreliable slaves do the trick? Cheers, Mikkel
