CBQE-0: add logs

Change-Id: I5540fcef26a73c67baccfb36655b82df6fbce96b
Reviewed-on: http://review.couchbase.org/30955
Reviewed-by: Iryna Mironava <irynamironava@yandex.ru>
Tested-by: Iryna Mironava <irynamironava@yandex.ru>