Interleaving maps/reduces from multiple jobs on the same tasktracker

[Jiaqi Tan]

Hi,

Will Hadoop ever interleave multiple maps/reduces from different jobs
on the same tasktracker?

Suppose I have 2 jobs submitted to a jobtracker, one after the other.
Must all maps/reduces from the first submitted job be completed before
the tasktrackers will run any of the maps/reduces from the second
submitted job?

Thanks.

Jiaqi Tan