MB-9343 added some log output for diagnostic

Change-Id: I924a582ce2119ec29fe8a9b0596cec9c4735555d
Reviewed-on: http://review.couchbase.org/32570
Tested-by: Artem Stemkovski <artem@couchbase.com>
Reviewed-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>