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Tom White commented on HDFS-326: -------------------------------- bq. switch to Git to keep changes more isolated And make maintaining patches easier (using rebase). See http://www.apache.org/dev/git.html#workflow. bq. get the base changes into -common, then worry about hdfs and mapred as separate issue +1 This should make the changes more isolated too, and make them easier to review. > Add a lifecycle interface for Hadoop components: namenodes, job clients, etc. > ----------------------------------------------------------------------------- > > Key: HDFS-326 > URL: https://issues.apache.org/jira/browse/HDFS-326 > Project: Hadoop HDFS > Issue Type: Improvement > Reporter: Steve Loughran > Assignee: Steve Loughran > Attachments: AbstractHadoopComponent.java, HADOOP-3628-18.patch, > HADOOP-3628-19.patch, hadoop-3628.patch, hadoop-3628.patch, > hadoop-3628.patch, hadoop-3628.patch, hadoop-3628.patch, hadoop-3628.patch, > hadoop-3628.patch, hadoop-3628.patch, hadoop-3628.patch, hadoop-3628.patch, > hadoop-3628.patch, hadoop-3628.patch, hadoop-3628.patch, hadoop-3628.patch, > hadoop-3628.patch, hadoop-3628.patch, hadoop-3628.patch, > hadoop-lifecycle-tomw.sxw, hadoop-lifecycle.pdf, hadoop-lifecycle.pdf, > hadoop-lifecycle.sxw > > > I'd like to propose we have a standard interface for hadoop components, the > things that get started or stopped when you bring up a namenode. currently, > some of these classes have a stop() or shutdown() method, with no standard > name/interface, but no way of seeing if they are live, checking their health > of shutting them down reliably. Indeed, there is a tendency for the spawned > threads to not want to die; to require the entire process to be killed to > stop the workers. > Having a standard interface would make it easier for > * management tools to manage the different things > * monitoring the state of things > * subclassing > The latter is interesting as right now TaskTracker and JobTracker start up > threads in their constructor; that's very dangerous as subclasses may have > their methods called before they are full initialised. Adding this interface > would be the right time to clean up the startup process so that subclassing > is less risky. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.