I have GraphQL Subscriptions on my Apollo server that I want to close after the user logs out. The initial question is whether we should close this (socket) connections on the client side or in the backend.
On the front-end, I am using Angular with Apollo Client and I handle GraphQL subscriptions by extending the Subscription class from apollo-angular. I am able to close the subscription channels with a typical takeUntil rxjs implementation:
this.userSubscription
.subscribe()
.pipe(takeUntil(this.subscriptionDestroyed$))
.subscribe(
({ data }) => {
// logic goes here
},
(error) => {
// error handling
}
);
However, this does not close the websocket on the server, which If I'm right, will result in a subscription memory leak.
The way the Apollo Server (and express) is set up for subscriptions is as follows:
const server = new ApolloServer({
typeDefs,
resolvers,
subscriptions: {
onConnect: (connectionParams, webSocket, context) => {
console.log('on connect');
const payload = getAuthPayload(connectionParams.accessToken);
if (payload instanceof Error) {
webSocket.close();
}
return { user: payload };
},
onDisconnect: (webSocket, context) => {
console.log('on Disconnect');
}
},
context: ({ req, res, connection }) => {
if (connection) {
// set up context for subscriptions...
} else {
// set up context for Queries, Mutations...
}
When the client registers a new GraphQL subscription, I always get to see console.log('on connect'); on the server logs, but I never see console.log('on Disconnect'); unless I close the front-end application.
I haven't seen any example on how to close the websocket for subscriptions with Apollo. I mainly want to do this to complete a Logout implementation.
Am I missing something here? Thanks in advance!
