In Nest.js, I am using tcp architecture for microservice communication, in socket.io connection, I am able connect the microservice as show below but I am not able to read the response.
this.client.emit<any, any>('getSingleRoom', payload);
this.client.send({ service: 'getSingleRoom' }, payload).toPromise();
Both the code connect with microservice but, I am not able to read out this response so that I can emit in main server. I am using web socket in nest.js.
this.client.send<any, any>('sendMessagesInRoom', pay).toPromise();
You can use firstValueFrom, from rxjs.
await firstValueFrom(this.client.send<any, any>('sendMessagesInRoom', pay))
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I'm using the spring framework's spring-graphql library to create a graphql client, as per the docs. When connecting to the server using a websocket for subscriptions, everything works fine for 5 minutes but then the websocket times out and disconnects. It turns out the server requires the client to send a ping message to keep the websocket alive. This is a graphql ping message as specified in the graphql-ws protocol
I've checked in the docs and had a dig around in the code but can't see any way to send this ping message via the spring graphql client. Apollo client has similar functionality to what I'm after via a "keepalive" option in the graplq-ws ClientOptions. Is there any equivalent I can use via spring or alternative way to solve this?
I couldn't find any way to do this so raised an issue on github, and subsequently a PR with some changes to add basic support for sending pings.
See https://github.com/spring-projects/spring-graphql/pull/608
and https://github.com/spring-projects/spring-graphql/issues/605
I am trying to implement a GraphQL WebSocket-based #subscription on a server (using NestJS #subscription). The server is hosted on an AWS ECS and is behind an ALB.
We currently have an AWS API GW connection via VPC-link to our ALB.
I tried to build a dedicated Websocket API GW with the same VPC link we use in the HTTP API GW.
I also tried to spin up a new NLB (Network Load Balancer) over our ECS and a new REST VPC link to be used in the dedicated Websocket API GW.
The client and server are communicating over a graphql-transport-ws sub-protocol using graphql-ws library and the communication is working fine on a localhost setup.
When running the following command on our local host I am able to establish a web socket connection:
wscat -c ws://localhost:3000/graphql -s graphql-transport-ws
When running the same against the WebSocket API GW URL
wscat -c wss://*****.execute-api.*****.amazonaws.com/**** -s graphql-transport-ws
I’m getting this:
error: Server sent no subprotocol
The error indicates a problem with the sub-protocol so when removing the sub-protocol a connection is established and I am getting a prompt:
Connected (press CTRL+C to quit)
>
However, there’s no indication of reaching the server and it seems like the connection is only made with the WebSocket API GW itself.
When I circumvent the gateway and directly connect an internet-facing NLB I'm able to establish a WebSocket connection.
I am not a super Websocket expert, but I understand WebSocket connections will be terminated by the API Gateway and cannot be used as a connection pass-through. You can forward web socket events using AWS_PROXY integration to a graphQL server backend, BUT it's not a maintained direct connection - API Gateway terminates and events towards the backend integration and will not return the integration response to the WebSocket since it is event-driven and not a connection-oriented service - hence the “error: Server sent no subprotocol” you are seeing.
So to use API GW as the WebSocket layer, you would need to build out connection management functionality somewhere to manage the event-based nature of the APIGW and send out data to the APIGW connections or adjust the integration mechanism within the graphql server to utilise the #connection functionality to send responses/notifications to WebSocket consumers.
Integrating Backend Service documentation:
https://docs.aws.amazon.com/apigateway/latest/developerguide/apigateway-websocket-api-routes-integrations.html
Sending responses to a connected client:
https://docs.aws.amazon.com/apigateway/latest/developerguide/apigateway-how-to-call-websocket-api-connections.html
API GW Websockets are great for building custom solutions but take some effort since you will be configuring the setup for the events.
For a GraphQL API on AWS - I would recommend taking a look at AppSync, which is an AWS Managed GraphQL service - it handles GraphQL subscriptions via WebSockets natively and with zero additional code and its highly scalable out of the box and would simplify the GraphQL hosting burden of an ECS based solution.
I suspect there may be a lot of other reasons for the need to build out using existing GraphQL on ECS, so understand it's not always possible to pivot to something like AppSync. I feel the NLB solution you tried is okay within the existing ECS backend landscape and, as you have noted, is connection-oriented (via NLB), so will achieve the outcome you are after.
I have a situation where I need to publish the data from grpc server (streaming )data to
Nats io publisher ,this nats io would be subscribed by many clients
Grpc Server ----->Nats Io -->Clients
How can I achieve that ,I was able to send data from GRpc server --->Grpc client in go and then was able to publish on nats server
But I don't want to involve the grpc client in between .Any idea how to achieve it
I have implemented mqtt using server connection tcp socket on my machine with mosquitto broker. I have totally understood the mqtt protocol and its frame format. I want to publish my data over webserver which supports mqtt over websocket.
How can I start with this thing?
I am not clear with websocket concept
Can I implement websocket using tcp or is there any other method.
do i have to use http to implement mqtt over web socket as to send data over webserver?
As http and mqtt use different methods to send or receive data.
I don't want to use ready libraries such as paho.
I am totally new to this socket programming.any help or guideline will greatly appreciated!!!
Websockets are an extension to the HTTP protocol, you need to use a correctly formatted HTTP request to setup a new Websocket connection.
Once the connection is setup it can be used to send the exact same binary MQTT packets that you would send over an existing TCP connection.
I suggest you look at using an existing library like libwebsockets to handle the Websocket connection setup, then you should be able to interface your existing code to just use the websocket handle instead of the socket handle.
If you REALLY don't want to use a library then you will need to start by reading the Websocket RFC https://www.rfc-editor.org/rfc/rfc6455
I have developed a chat application by using Spring Stomp and socketjs .
I have successfully connected to the websocket over my clients but I can not connect to websocket by using Advanced Restclient -> socket implementation.
Why?
Thanks
if i didnt use socketjs , i can succeed to connect over Advanced Rest Client. To connect websocket without using socketjs, you should set the allowed origins : setAllowedOrigins('*')
Also if you are using stomp without socketjs , you can succeed to open a websocket connection via Advanced Rest Client, because stomp just a sub-protocol over websocket connection. But to receive messages over websocket, you should subscribe to STOMP queue, it is impossible with Advanced Rest Client.
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Restclients runs on http protocol. Restclients not yet understand the web socket and sock JS protocol. That is the reason your rest client didn't connected to server.