I am trying to persist server side sessions, even after the client has disconnected.

I have a standard SockJS client and sockjs-node setup.

The idea is that if a Client connects, then disconnects, and then re-connects to the server; the client should get back the same session from the server on every connection.

To try and achieve this, I am currently generating a random session ID string on the client side then I am passing this ID to the sockJS server.

The problem I am facing is that the Server Returns null when I pass the sessionID to the server to try and retrieve an existing session.

As far as I can see, this is how SockJS implements session persisting: https://github.com/sockjs/sockjs-node/blob/master/lib/session.js

I don't quite understand why I am getting back null, the session should be maintained on the server...?

I am trying to persist server side sessions, even after the client has disconnected.

I have a standard SockJS client and sockjs-node setup.

The idea is that if a Client connects, then disconnects, and then re-connects to the server; the client should get back the same session from the server on every connection.

To try and achieve this, I am currently generating a random session ID string on the client side then I am passing this ID to the sockJS server.

The problem I am facing is that the Server Returns null when I pass the sessionID to the server to try and retrieve an existing session.

As far as I can see, this is how SockJS implements session persisting: https://github.com/sockjs/sockjs-node/blob/master/lib/session.js

I don't quite understand why I am getting back null, the session should be maintained on the server...?

This is how I currently send the ID to the SockJS Server:

// (1) How I currently send the ID to the SockJS Server.
const socket = SockJS("${apiServerURL}/socket/auth/login", null, {
  sessionId: () => {
    // (2) Check if a session ID already exhists
    let sessionId = localStorage.getItem("sockjsSessionId");


    if(sessionId === null || sessionId === undefined) {

      // (3) If Session ID does not exist, create a random ID.
      sessionId = getRandomStringWithLength(8);
      localStorage.setItem("sockjsSessionId", sessionId);
    }

    // (4) Pass session id to SockJS Server
    return sessionId;
  }
})

This is how I currently am trying to retrieve the same session on the Server:

if (sessionId !== null && typeof sessionId !== "undefined") {
  const socketSession: SockJSSession | null = SockJSSession.bySessionId(sessionId);
  console.log("found sockjs session connection", socketSession);
  if (socketSession !== null) {
    socketSession.connection.write(JSON.stringify(response));
  }
}