> Could someone throw some light as to how intuitively fixed-type slots in > Hadoop have a negative impact of cluster utilization as mentioned in Arun's > blog?
It's pretty simple: in the course of time, a real cluster with a mix of job types and submission times will have periods of high map-slot usage (with reduce-slots available), and vice versa. Being able to assign machine resources to whatever kind of task needs them at any given time means you're not wasting those resources. In short: map- vs. reduce-slots is an artificial and unnecessary restriction. Greg
