The exception handling code in com.google.datastore.v1.client.RemoteRpc does not close the HTTP content input stream after parsing the protobuf message com.google.rpc.Status (which describes the Datastore error).

Closing the content input stream allows the underlying HttpTransport to clean up resources (i.e. release the leased HTTP connection back to the connection pool). Without cleanup, alternative HttpTransport implementations (e.g. ApacheHttpTransport) experience connection timeouts as soon as they have depleted their connection pool.