real-time-chat-application | time private and group messaging chat application | Runtime Evironment library

I have a react application and I would like to setup a websocket connection to my backend for some realtime updates. I was going to deploy an EC2 or ECS-cluster to host websocket connections. Then I stumbled into some articles showing how websocket connection can be setup in a serverless manner.

One example: https://medium.com/@likhita507/real-time-chat-application-using-webscockets-in-apigateway-e3ed759c4740

However, I can't seem to figure out how this works for a few reasons.

• Lambda has a max runtime of 15 min
• How does the backend establish a connection when no lambda is running and the backend wants to invoke a message to the frontend

Does this entail that I have to keep a lambda alive all the time, if so, it no longer feels like a good idea. In the above example, what I can't grasp is that when creating that chat application, can each chat room only exist for 15 min? And if a user disconnects from the room, how will that user be updated on new messages.

Does anyone have any experience with this kind of solution?

I am following this tutorial. With this link you can see my comment for the particular problem, I followed this tutorial and I was at success to send and receive text messages on both peers. I can also see my Firebase database from console and its updating as well. Thing working fine till here.

Now, I want to send/receive camera images to Firebase, so I found various methods to convert a image to Base64 encode string, upload that string to Firebase database, I am success at this also.

I have successfully uploaded the encoded string to Firebase. Now as my current system is build for only text string messages application got crash when it receives encode string .

1. How to decode encoded string back to bitmap?

2. Show bitmap image thumbnail in MessageBox

Here is my modified chat.java activity code: as a reference you can follow the provided url up for chat.java class and how it works originally, but I am unable to achieve decoding and showing bitmap thumbnail in messagebox.

chat.java

I'm trying to use AppSync for chatting application. I'm able to reproduce the AWS tutorial (https://aws.amazon.com/blogs/mobile/building-a-serverless-real-time-chat-application-with-aws-appsync/)

However, I'm still not sure if AppSync can handle a production environment for chatting application. Will it be expensive because of the DynamoDB part?

Moreover, if I'm subscribing each conversation, will there be a performance issues for the users in the front-end if I have like 1000 conversations / user?

I am new to firebase. I tried to store user data in firebase database using volley. However, firebase has no response regarding my volley request and the database still is null. This is the tutorial I followed.

This is the volley request I used to connect firebase.