Hi Arv, 1) look for info on "secondary NameNode" on the Hadoop wiki and ML archives.
2) I don't think a NN is supposed to restart a killed DN. I haven't tried it, haven't seen it, but haven't read that anywhere either. 3) I think bin/start-dfs.sh is what you are after, no? Or at least the one of the last couple of lines from there. Otis -- Sematext -- http://sematext.com/ -- Lucene - Solr - Nutch ----- Original Message ---- > From: Arv Mistry <[EMAIL PROTECTED]> > To: core-user@hadoop.apache.org > Sent: Tuesday, May 6, 2008 3:04:56 PM > Subject: Hadoop Resiliency > > > Hi folks, > > I'm new to hadoop and just had a few questions regards resiliency > > i) Does hadoop support redundant NameNodes? I didn't see any mention of > it. > > ii) In a distributed setup, when you kill a DataNode, should the > NameNode restart it automatically? I see the NameNode detects > (eventually) that its down but it never seems to restart it. Is the > expectation that some kind of wrapper (e.g. Java Service Wrapper) will > do this. > > iii) Maybe an obvious one, but I couldn't see how you just start a > DataNode from the scripts. Should I create my own script to do that, > based on start_dfs? > > Cheers Arv >
