How to manage graphql-ws client at the gateway for different users

[quant-daddy]

In my architecture, each client (browser) connects to the gateway. The gateway then connects with the appropriate upstream graphql subscription service, creating a separate upstream websocket connection for each downstream connection using the code below

const clients: {
  [key: string]: { [userId: string]: Client };
} = {};

const getClient = (url: string, userId: string | null) => {
  let client: Client | null = null;
  if (!userId || !clients[url] || !clients[url][userId]) {
    client = createClient({
      url,
      webSocketImpl: ws,
      connectionParams: {
        userId: userId,
      },
      on: {
        closed: () => {
          console.log("closed url ", url);
        },
        connected: () => {
          console.log("connected url ", url);
        },
      },
    });
    // if a client is create for a user, the cache it
    if (userId) {
      clients[url] = {
        ...clients[url],
        [userId]: client,
      };
    }
  }
  // return the cached version for a user
  if (userId) {
    return clients[url][userId];
  }
  // for non users, return the generated client
  return client as Client;
};

What is recommended way to manage connections at scale: Can we use the same websocket connection for multiple downstream client connection? I think not. I have added more details in this issue. Would love to hear your thoughts @enisdenjo.