Pub/Sub vs Bidirectional Streaming in gRPC for chat service - redis

Which one is more suitable between Pub/Sub (redis) with server streaming and Bidirectional Streaming without pub/sub to make chat service?
Both works well, but I want to know the pros and cons on each side.
I found some repos which use pub/sub way instead of Bidirectional Streaming, I just wonder why

Related

Is gRPC suitable for push notification?

Currently I am using SignalR for push notification, but due to cost constrain looking for the new alternative. When I read about gRPC its mostly used for microservice communication. Will this gRPC is suitable for web push notification? is there any example I can find. Thanks.

ServiceStack Messaging API: Can it make a broadcast?

As I have previously mentioned, I am using ServiceStack Messaging API (IMessageQueueClient.Publish) as well as the more low-level IRedisClient.PublishMessage.
I use the Messaging API when I need a specific message/request to be processed by only one instance of a module/service, so even though I might have several modules running that all listens for MyRequest, only one service receives the message and processes it.
I use the IRedisClient.PublishMessage when I do a broadcast, a pub/sub situation, sending a request that everyone should receive that listens on that specific Redis channel.
However, I am in a situation where it would be useful to use the Messaging API, but do a broadcast, so that all instances that are listening to a specific message type, gets the message, not just the one.
(The reason for this is to streamline our usage of Redis and how we subscribe to events/request, but I will not get into details about this now. A little more background on this is here.)
Is there a "broadcast way" for the Messaging API?
No, the purpose of ServiceStack Messaging is simply to invoke ServiceStack Services via MQ. Any other MQ features is outside the purpose & scope of ServiceStack MQ, you'd need to instead develop against the MQ Provider APIs directly to access their broadcast features.
Server Events is a ServiceStack feature that supports broadcasting messages to subscribers of user-defined channels, but its a completely different implementation that serves a different use-case for sending "server push" real-time events over HTTP or gRPC, e.g. it doesn't use MQ brokers and pub/sub messages aren't persistent (i.e. only subscribers at time messages are sent will receive them).

Using RabbitMQ for communication in a Microservice architecture but should I create a API Gateway on top?

I basically have a smaller software that is using the Microservice architecture. I am currently using RabbitMQ to do the communication between UI and services and that works great.
However I am thinking about creating a new microservice, a API Gateway, that basically takes the RabbitMQ logic from the UI and encapsulate into a service, which would become the entry point to all the other services.
The benefit is that I would encapsulate the logic that give access to the services and also being able to add authentication in the API Gateway.
However I would need to use HTTP request to interact with the API as I am moving the messaging logic from the UI. Could there be any major drawbacks in this approach?
I have being able to find examples about RabbitMQ and examples about API Gateways but never those two together, I might just be overthinking it a bit.

Signalling channel for WebRTC

I want to create my own video chat application. I use the WebRTC framework. I read a few tutorials and each of theme assumes that signalling channel exists. How to implement my own signalling channel?
Since signalling is not defined for the WebRTC standard at the moment, it leaves you a few options. Check out this article for more info the following articles:
Signalling Options for WebRTC Applications
Choosing your signalling protocol
1.SIP over WebSockets
Companies like JSSIP offer a SIP signalling framework over Javascript. The advantage here is that it's interoperable with the usual VoIP structures.
JSSIP
SIPJS
SIPML5
2.The WebRTC Data Channel
Uncharted territory but viable!
Tutorial by Pusher
3.XMPP
If you take this route, it is probably either because you have an existing XMPP installation
Jingle
4.JSON over COMET or WebSockets
My favourite! WebRTC signalling shouldn't be done any other way than the Web way.
Matrix
Firebase
I hope this helps!
You can make a Node.js WebSocket server or other WebSocket server to broker the connection. Here is a simple guide that gets the first client talking to the server. An alternative is PeerJS, which can handle the signaling and alleviate most of the complexity of setting up the WebRTC call.
With serverless options available, vanilla HTTP AJAX options may not be bad for scalability and costs.
Create a plain HTTP(s) API exchanging information using JSON.

Microservice, Queue vs HTTP request

We have a backend with a dozen of workers in python connected to rabbitMQ with celery. We have also the API gateway in Django with postgresql. The context between workers is handled by the DB.
We would like:
To decouple the DB and the workers,
To be able to make workers in Go.
We looked at the microservice infrastructure and this seems very interesting. What we don't understand is what kind of Request/Response pattern we should use and how we can handle the context of a request between workers without using a common db.
Microservice articles deal with notifications and subscription. Is this applicable to this situation or should we use HTTP request. Is the RPC pattern used? This pattern seems to be very heavy.