RE: Job Tracker/Name Node redundancy
Ryan, >From the MR (JobTracker) side we have a failover support. If a large job is submitted and the JobTracker fails midway then you can start the JobTracker on the same host and resume the job. Look at https://issues.apache.org/jira/browse/HADOOP-3245 for more details. Hope that helps. Amar -Original Message- From: Ryan LeCompte [mailto:lecom...@gmail.com] Sent: Fri 1/9/2009 12:09 PM To: core-user@hadoop.apache.org Subject: Job Tracker/Name Node redundancy Are there any plans to build redundancy/failover support for the Job Tracker and Name Node components in Hadoop? Let's take the current scenario: 1) A data/cpu intensive job is submitted to a Hadoop cluster of 10 machines. 2) Half-way through the job execution, the Job Tracker or Name Node fails. 3) We bring up a new Job Tracker or Name Node manually. -- Will the individual task trackers / data nodes "reconnect" to the new masters? Or will the job have to be resubmitted? If we had failover support, we could setup essentially 3 Job Tracker masters and 3 NameNode masters so that if one dies the other would gracefully take over and start handling results from the children nodes. Thanks! Ryan
Re: Job Tracker/Name Node redundancy
Hey Ryan, Some specific JIRA tickets that will help narrow your search: JT: https://issues.apache.org/jira/browse/HADOOP-4586 NN: https://issues.apache.org/jira/browse/HADOOP-4539 Would love to hear your thoughts there! Regards, Jeff On Fri, Jan 9, 2009 at 12:36 PM, Otis Gospodnetic < otis_gospodne...@yahoo.com> wrote: > Yes, there is a JIRA issue for a redundant JobTracker already. > The NN redundancy scenario is mentioned on the Wiki (look for > SecondaryNameNode). > > Otis > > -- > Sematext -- http://sematext.com/ -- Lucene - Solr - Nutch > > > > - Original Message > > From: Ryan LeCompte > > To: "core-user@hadoop.apache.org" > > Sent: Friday, January 9, 2009 3:09:13 PM > > Subject: Job Tracker/Name Node redundancy > > > > Are there any plans to build redundancy/failover support for the Job > > Tracker and Name Node components in Hadoop? Let's take the current > > scenario: > > > > 1) A data/cpu intensive job is submitted to a Hadoop cluster of 10 > machines. > > 2) Half-way through the job execution, the Job Tracker or Name Node > fails. > > 3) We bring up a new Job Tracker or Name Node manually. > > > > -- Will the individual task trackers / data nodes "reconnect" to the > > new masters? Or will the job have to be resubmitted? If we had > > failover support, we could setup essentially 3 Job Tracker masters and > > 3 NameNode masters so that if one dies the other would gracefully take > > over and start handling results from the children nodes. > > > > Thanks! > > > > Ryan > >
Re: Job Tracker/Name Node redundancy
Yes, there is a JIRA issue for a redundant JobTracker already. The NN redundancy scenario is mentioned on the Wiki (look for SecondaryNameNode). Otis -- Sematext -- http://sematext.com/ -- Lucene - Solr - Nutch - Original Message > From: Ryan LeCompte > To: "core-user@hadoop.apache.org" > Sent: Friday, January 9, 2009 3:09:13 PM > Subject: Job Tracker/Name Node redundancy > > Are there any plans to build redundancy/failover support for the Job > Tracker and Name Node components in Hadoop? Let's take the current > scenario: > > 1) A data/cpu intensive job is submitted to a Hadoop cluster of 10 machines. > 2) Half-way through the job execution, the Job Tracker or Name Node fails. > 3) We bring up a new Job Tracker or Name Node manually. > > -- Will the individual task trackers / data nodes "reconnect" to the > new masters? Or will the job have to be resubmitted? If we had > failover support, we could setup essentially 3 Job Tracker masters and > 3 NameNode masters so that if one dies the other would gracefully take > over and start handling results from the children nodes. > > Thanks! > > Ryan
