MB-100: high thruput nodgm load

Change-Id: I30a04e774b6fd5e41ac6741bb53eef5581c49664
Reviewed-on: http://review.couchbase.org/28333
Reviewed-by: Ronnie Sun <ronnie@couchbase.com>
Tested-by: Ronnie Sun <ronnie@couchbase.com>