These are the new flags:

--datastore-connpool-read-max-open int                     number of concurrent connections open in a remote datastore's connection pool (default 20)
      --datastore-connpool-read-min-open int                     number of minimum concurrent connections open in a remote datastore's connection pool (default 20)
      --datastore-connpool-write-max-open int                    number of concurrent connections open in a remote datastore's connection pool (default 10)
      --datastore-connpool-write-min-open int                    number of minimum concurrent connections open in a remote datastore's connection pool (default 10)