improve connection draining and logging
improve connection draining and logging

Signed-off-by: Alex Suraci <a8053324ea51f0cc533cfe7b17f8bee3c920919f@pivotallabs.com>

cloudfoundry-incubator/garden,tsaleh/garden,savaki/garden,tangfeixiong/garden,savaki/garden,tsaleh/garden,cloudfoundry-incubator/garden,tangfeixiong/garden