Owen, Could you show me how to start additional data nodes or tasktrackers ?
2007/10/19, Owen O'Malley <[EMAIL PROTECTED]>: > > On Oct 18, 2007, at 8:05 PM, Ming Yang wrote: > > > In the original MapReduce paper from Google, it mentioned > > that healthy workers can take over failed task from other > > workers. Does Hadoop has the same failure recovery strategy? > > Yes. If a task fails on one node, it is assigned to another free node > automatically. > > > Also the other question is, in the paper, it seems the nodes can > > be added/removed while the cluster is running jobs. How does > > Hadoop achieve this? Since the slave locations are saved in the > > file and the master doesn't know about new nodes until it > > restart and reload the slave list. > > The slaves file is only used by the startup scripts when bringing up > the cluster. If additional data nodes or task trackers (ie. slaves) > are started they automatically join the cluster and will be given > work. If the servers on one of the slaves are killed, the work will > be redone on other nodes. > > -- Owen > > >
