Alan, You shouldn't need to worry about moving the data blocks off your node, assuming you're replicating your blocks 3x times. (I think its the default...)
You can bring down your node, and within 15 mins, Hadoop will recognize that node as down... I think if you do a $> hadoop fsck / your system will recognize that those blocks are under replicated and will replicate the blocks on another machine. If you're decommissioning ?sp? a node, then you're taking the machine out of the cluster permanently. I'm also not sure how dropping a node will test the scalability. You would be testing resilience. HTH -Mike > Date: Tue, 6 Jul 2010 16:31:58 +0200 > To: [email protected] > From: [email protected] > Subject: decomission a node > > Hi, > > Is it possible move all the data blocks off a cluster node and then > decommision the node? > > I'm asking because, now that my MR job is working, I'd like see how things > scale. I.e., > less processing nodes, amount of data (number & size of files, etc.). I > currently have 8 nodes, > and am processing 5GB spread across 2000 files. > > Alan _________________________________________________________________ Hotmail is redefining busy with tools for the New Busy. Get more from your inbox. http://www.windowslive.com/campaign/thenewbusy?ocid=PID28326::T:WLMTAGL:ON:WL:en-US:WM_HMP:042010_2
