Looks like there is not much activity in the hdfs-user list. So, am reposting it in the general list.
Hi guys. I have a few related questions. I am going to layout the steps I have taken. Please comment on what I can do better. I was trying to to add 5 nodes to my existing 10 node cluster and also increase the replication factor from 2 to 3. I thought I don't have to run the balancer cause it would most likely put the new replicas into the new nodes. There are about 500k blocks. I wanted to get it all stabilized(replication and balancing) within 24 hours. Its more than 24 hours now and fsck reports 30% under replication. Is there a way to force hdfs to use balance/replicate more aggressively. It would be great if someone explained what/when things happen to blocks in the context of 1) Rebalancing 2) -setrep 3) Restarting cluster with a higher/lower replication factor. A few questions and a few issues here. 1) When you restart the cluster with a higher than previous replication value. Does it also apply to existing blocks or only to new blocks being created ? 2) Does the balancer take into account under replication of blocks or does it blindly start moving existing blocks to reach threshold ? A very specific problem . I am having this strange problem where the -setrep hangs on one particular block for hours. Is this because its corrupt ?. But, fsck said its healthy. Thanks Arun
