[Moving to mapreduce-dev, copying common-dev] Hi,
On Thu, Sep 9, 2010 at 11:30 AM, radheshyam nanduri <[email protected]> wrote: > Hi, > > I am working on writing a scheduler plugin for Hadoop. Currently, the model supported to plug-in schedulers to Hadoop is to extend the TaskScheduler class in o.a.h.mapred package. Primarily what a 'plug-in' scheduler can do is that given a set of jobs and a tasktracker, it can assign one or more suitable tasks to the tasktracker. The scheduler will have flexibility in choosing the job and the tasks it wants to schedule. You can take a look at some of the existing schedulers like CapacityTaskScheduler or FairScheduler to see what they do and how. > I have divided the job received into number of tasks. This is already done in the framework when a job is submitted. Are you overriding this ? Can you explain what you are doing in some more detail ? > My task now is to assign a task on to a particular TaskTracker. > I want to start the Task right away with a method which accepts the Task and > TaskTracker as arguments. I am not sure I am following this. A task needs to be sent via Hadoop's RPC mechanisms to a tasktracker where it should be executed. So, conceptually, it is the tasktracker that has an RPC method which accepts tasks to launch. The task is launched typically straight-away, but in case of certain scheduling choices, it could have to wait for a short while to get a free slot to execute. > Could you guide me on doing this. It may be better if you can describe what you want the plug-in scheduler to achieve. Thanks Hemanth > > > Thanks in advance. > > > -- > Radheshyam Nanduri >
