From this error we cannot make sure what's the problem.
Because that only let us know your server side response so slow so timeout.
I think maybe you want to upload your sample for that with your test data, so we can double check whether your render logic have any problem.
For web edition, we suggest you choose GoogleMapsOverlay but not GoogleMapsLayer. Overlay will directly get image tile from Google's server, the layer will get tile into your server side, then sent back to your client side.