google local home 1500ms timeout issue - google-smart-home

Question

I am working on a Google Home Local Fulfillment project following "Enable local fulfillment for smart home Actions" tutorial on the Google Codelabs.
The project is only focus on local control without accessing remote control.
I need to run a query on my firestore database at executeHandler before I run this.app.getDeviceManager().send(deviceCommand).
This will give me timeout errors as below.
statusType: "RESPONSE_UNAVAILABLE"
isSuccess: false
externalDebugString: "Pubsub failed with 1500ms timeout."
Is there a way I can set the timeout more than 1500ms?
The following is my code of executeHandler:
executeHandler(request: IntentFlow.ExecuteRequest):
Promise<IntentFlow.ExecuteResponse> {
// TODO: Implement local execution
console.log("EXECUTE intent: " + JSON.stringify(request, null, 2));
const command = request.inputs[0].payload.commands[0];
const execution = command.execution[0];
const response = new Execute.Response.Builder().setRequestId(request.requestId);
const promises: Array<Promise<void>> = command.devices.map(async (device) => {
console.log("Handling EXECUTE intent for device: " + JSON.stringify(device));
// Convert execution params to a string for the local device
const params = execution.params as IFireplaceParams;
const tcpMsg = 'MWIB2,02';
const payload = this.stringToHex(tcpMsg);
console.log("Sending request to the smart home device:", payload);
const firebaseDataObj = await this.queryFirebase(device.id);
console.log("firebaseDataObj:", JSON.stringify(firebaseDataObj));
// Construct a local device command over TCP
const deviceCommand = new DataFlow.TcpRequestData();
deviceCommand.requestId = request.requestId;
deviceCommand.deviceId = device.id;
deviceCommand.data = payload;
deviceCommand.port = SERVER_PORT;
deviceCommand.operation = Constants.TcpOperation.WRITE;
try {
const result = await this.app.getDeviceManager().send(deviceCommand);
console.log("Sending deviceCommand result:", JSON.stringify(result));
const state = { online: true };
response.setSuccessState(result.deviceId, Object.assign(state, params));
} catch (err) {
err.errorCode = err.errorCode || 'invalid_request';
response.setErrorState(device.id, err.errorCode);
console.error('An error occurred sending the command', err.errorCode);
}
});
return Promise.all(promises)
.then(() => {
return response.build();
})
.catch((e) => {
const err = new IntentFlow.HandlerError(request.requestId, 'invalid_request', e.message);
return Promise.reject(err);
});
}

Answer 1

Communicating directly with external service from the local home app is not recommended as it might not be supported across all supported execution environments:
https://developers.google.com/assistant/smarthome/concepts/local#execution-environment
The documentation recommends instead to pass additional data required for execution as part of the customData fields of the SYNC response:
https://developers.google.com/assistant/smarthome/develop/local#update_sync_response_in_the_cloud_fulfillment