There are 3 types of locality.
- data local (node local) - your task gets scheduled on the node where the
- rack local - your task is scheduled on the same rack as the data
(usually 20-40 nodes in a rack), but its not on the exact node with the
- off-switch (off-rack) - your task is scheduled on a different rack then
your data is located.
So off-switch it on a different rack. Generally its less expensive to
fetch the data when its in the same rack vs off rack.
On 3/3/13 2:13 AM, "Jagmohan Chauhan" <[EMAIL PROTECTED]> wrote:
>I am going through the Capacity Scheduler implementation. There is one
>thing i did not understand clearly.
>1. Does the o ff-switch task refers to a task in which data has to be
>fetched over the network. It means its not node-local ?
>2. Does off-switch task includes only the tasks for which map input has
>be fetched from a node on a different rack across the switch or it also
>includes task where data has to be fetched from another node on same rack
>on same switch?
>Thanks and Regards
>Univ. of Saskatchewan
>IEEE Graduate Student Member