Error: “Could not connect to server within allotted time”

Hey guys:
This error bother me for a long time, and I google it but found nothing valuable.
I got this error “Could not connect to server within allotted time”. When it apperas, load of CPU becomes high.
Any help will be appreciated so much.

How much CPU utilization do you have on average across the cluster? does this go away if you add nodes?
thanks
-cihan