Reputation: 453
NodeJS is used as run time in this case and AWS Lambda is used as event notifier (updates comes from other lambda or DB).
My challenge is, the "user browser" can also be a mobile client. The "API" should acts as a service which allows client (mobile or web) to subscribe, unsubscribe, or publish data, nothing else.
Can lambda works as API that has capabilities of "pushing events notifications" to directly clients?
Is there any solution and also sample work/source code can be used as POC?
Next question is, how can I scale such architecture since it becomes stateful (requires memory to remember states of clients connections)?
Or else, how possible is it persist client connections on DB (using frameworks like websocket or socket.io)?
Upvotes: 2
Views: 5667
Reputation: 2357
Can lambda works as API that has capabilities of "pushing events notifications" to directly clients?
Yes! As @AndyOS mentioned, SNS is a great service that is quite literally intended to send notifications. I won't go into details here to avoid duplication of response.
Is there any solution and also sample work/source code can be used as POC?
Or else, how possible is it persist client connections on DB (using frameworks like websocket or socket.io)?
If you are looking to use websockets, I'd encourage you to take a look at IoT (https://aws.amazon.com/iot). IoT supports the MQTT protocol (http://docs.aws.amazon.com/iot/latest/developerguide/protocols.html). This page also contains sample client-side code which might help you bootstrap your solution.
Next question is, how can I scale such architecture since it becomes stateful (requires memory to remember states of clients connections)?
You can view the service limits of IoT at http://docs.aws.amazon.com/general/latest/gr/aws_service_limits.html#limits_iot. You would need to decide if your app fits within these bounds, depending on the various metrics your app has (number of requests per second, number of concurrent connections, etc.).
Upvotes: 0
Reputation: 3606
AWS has the SNS service to send notifications, which you can use from Lambda.
You can also directly use the relevant platform's notification system e.g for iOS, Node has an "apn" module that is used to communicate with Apple's APNS service - it's straightforward to use and can be implemented in a Lambda function.
In brief:
Your iOS app registers for APNS which responds with an APNS device token. Your app should then send this to your API / server for storage.
Your API can then send notifications to APNS, referencing any device tokens, along with the private key file you create from the Apple Developer page.
APNS will send the notifications to the registered devices.
Here is a good tutorial.
Your other queries should perhaps be separate questions.
Upvotes: 3