Can you try setting the following in hadoop-site.xml at the name node and see if the time comes down to around a minute <property> <name>heartbeat.recheck.interval</name> <value>1</value> </property>
This effectively On Thu, Jan 22, 2009 at 9:42 AM, Hargraves, Alyssa <aly...@wpi.edu> wrote: > I was following the steps at <http://wiki.apache.org/hadoop/FAQ#17> to do > the decommission. However, you have to be patient with it since it seems to > take a long time. If it took 3-5 minutes with my nodes that have no data > and no jobs running, I can't imagine how long it would be for a real > cluster. One thing that I had trouble with originally was the fact that it > doesn't seem to work if your replication is set to be same as your number of > machines (since I was just testing things, I had replication set to 2 with 2 > machines, but that's not a good real-world example). > > The problem I'm having though (from Jeremy's reply earlier it sounds like > he misinterpreted it) isn't how long it is taking for the node to go from > decommissioned to being recognized by the master as dead. Whether or not > it's recognized as dead isn't something that matters for what I'm doing. > The real problem is that going from the In Service to Decommissioned state > is taking forever. Decommission In Progress lasts 3 to 5 minutes despite > the fact that there aren't jobs or data on those nodes. If anyone else has > any idea why that might be (I can see why it would take time if there are > jobs or data, but not otherwise) please let me know. > > - Alyssa > ________________________________________ > From: Rob Hamilton [...@lotame.com] > Sent: Thursday, January 22, 2009 12:26 PM > To: core-user@hadoop.apache.org > Subject: RE: Decommissioning Nodes > > I wasn't able to get decommissioning to work at all and found that just > taking the node down got it out of the cluster. What version are you running > and how are you initiating the decommissioning? > > -Rob > > > Rob Hamilton - VP Network Operations > P +1 (410) 379-2195 x 240 > E r...@lotame.com > 6085 Marshalee Drive, Suite 210 > Elkridge, MD 21075 > > > -----Original Message----- > From: Hargraves, Alyssa [mailto:aly...@wpi.edu] > Sent: Wednesday, January 21, 2009 7:35 PM > To: core-user@hadoop.apache.org > Subject: Decommissioning Nodes > > Hello Hadoop Users, > > I was hoping someone would be able to answer a question about node > decommissioning. I have a test Hadoop cluster set up which only consists of > my computer and a master node. I am looking at the removal and addition of > nodes. Adding a node is nearly instant (only about 5 seconds), but removing > a node by decommissioning it takes a while, and I don't understand why. > Currently, the systems are running no map/reduce tasks and storing no data. > DFS Health reports: > > 7 files and directories, 0 blocks = 7 total. Heap Size is 6.68 MB / 992.31 > MB (0%) > Capacity : 298.02 GB > DFS Remaining : 245.79 GB > DFS Used : 4 KB > DFS Used% : 0 % > Live Nodes : 2 > Dead Nodes : 0 > > Node Last Contact Admin State Size (GB) Used (%) > Used (%) Remaining (GB) Blocks > master 0 In Service 149.01 0 > 122.22 0 > slave 82 Decommission In Progress 149.01 0 > 123.58 0 > > However, even with nothing stored and nothing running, the decommission > process takes 3 to 5 minutes, and I'm not quite sure why. There isn't any > data to move anywhere, and there aren't any jobs to worry about. I am using > 0.18.2. > > Thank you for any help in solving this, > Alyssa Hargraves > > The information transmitted in this email is intended only for the > person(s) or entity to which it is addressed and may contain confidential > and/or privileged material. Any review, retransmission, dissemination or > other use of, or taking of any action in reliance upon, this information by > persons or entities other than the intended recipient is prohibited. If you > received this email in error, please contact the sender and permanently > delete the email from any computer. > > > -- Kumar Pandey http://www.linkedin.com/in/kumarpandey