Using the google-cloud package, node v 6 and npm-4.0.5 on my local macOS machine (10.11.6).
When performing a query to the datastore sometimes the database would spit it out Security Handshake failed logs (more frequently just after rebooting my express server).
After some seconds (3-4), the query is finally resolved.
The errors all look like this:

E0106 15:08:31.210244000 123145321271296 handshake.c:128] Security handshake failed: {"created":"@1483711711.210211000","description":"Handshake read failed","file":"../src/core/lib/security/transport/handshake.c","file_line":237,"referenced_errors":[{"created":"@1483711711.210204000","description":"FD shutdown","file":"../src/core/lib/iomgr/ev_poll_posix.c","file_line":427}]}

Here's a screenshot (after running a query to check if a user existed) :