Im using Express.js and socket.io/pm2 + typescript.

const clusterAdapter = createAdapter()(nsp);
io.adapter(clusterAdapter);
setupWorker(io);

io.adapter accepts AdapterConstructor
the error:

Argument of type 'ClusterAdapter' is not assignable to parameter of type 'AdapterConstructor'.
Type 'ClusterAdapter' is missing the following properties from type 'typeof Adapter': prototype, getEventListeners, addAbortListener, errorMonitor, and 5 more

At line:1 char:13

• npm install @socket.io/cluster-adapter

•         ~~~~~~~
  

The splatting operator '@' cannot be used to reference variables in an
expression. '@socket' can be used only as an argument to a command. To
reference variables in an expression use '$socket'.
+ CategoryInfo : ParserError: (:) [], ParentContainsErrorReco
rdException
+ FullyQualifiedErrorId : SplattingNotPermitted

I am using Socket.IO client and server 4.5.3 together with cluster adapter 0.2.1 and sticky 1.0.2.

When I do io.local.emit from a node (child worker) in the cluster, nothing happens. It seems like the emit doesn't work.

When I replace the emit by a loop over the result of io.local.fetchSockets, it does works. This seems like a bug. I cannot find anything online about people using io.local.

Hey! Nice work! I found an issue when I try to run a process in cluster mode using this library.

Description

When I run a process in cluster mode using the @socket.io/pm2 library and I try to delete them using pm2 delete all I get the following errors:

PM2             | Error [ERR_IPC_CHANNEL_CLOSED]: Channel closed
PM2             |     at ChildProcess.target.send (internal/child_process.js:680:16)
PM2             |     at Worker.send (internal/cluster/worker.js:45:28)
PM2             |     at EventEmitter.<anonymous> (/usr/lib/node_modules/@socket.io/pm2/node_modules/@socket.io/cluster-adapter/dist/index.js:392:32)
PM2             |     at EventEmitter.emit (events.js:314:20)
PM2             |     at EventEmitter.emit (domain.js:483:12)
PM2             |     at ChildProcess.<anonymous> (internal/cluster/master.js:191:13)
PM2             |     at Object.onceWrapper (events.js:421:26)
PM2             |     at ChildProcess.emit (events.js:314:20)
PM2             |     at ChildProcess.EventEmitter.emit (domain.js:506:15)
PM2             |     at Process.ChildProcess._handle.onexit (internal/child_process.js:276:12) {
PM2             |   code: 'ERR_IPC_CHANNEL_CLOSED'
PM2             | }

PM2             | Error: write EPIPE
PM2             |     at ChildProcess.target._send (internal/child_process.js:807:20)
PM2             |     at ChildProcess.target.send (internal/child_process.js:678:19)
PM2             |     at Worker.send (internal/cluster/worker.js:45:28)
PM2             |     at EventEmitter.<anonymous> (/usr/lib/node_modules/@socket.io/pm2/node_modules/@socket.io/cluster-adapter/dist/index.js:392:32)
PM2             |     at EventEmitter.emit (events.js:314:20)
PM2             |     at EventEmitter.emit (domain.js:483:12)
PM2             |     at ChildProcess.<anonymous> (internal/cluster/master.js:191:13)
PM2             |     at Object.onceWrapper (events.js:421:26)
PM2             |     at ChildProcess.emit (events.js:314:20)
PM2             |     at ChildProcess.EventEmitter.emit (domain.js:506:15) {
PM2             |   errno: 'EPIPE',
PM2             |   code: 'EPIPE',
PM2             |   syscall: 'write'
PM2             | }

It seems on exit it is trying to send the WORKER_EXIT message to disconnected workers.

if we set up pm2 to resurrect on failure, this causes the unexpected resurrection of the killed/deleted/stopped processes.

Based on this thread I think it is related to a synchronization error when multiple processes are closed at once. I was also able to delete the processes one by one without any problem.

I could mitigate the error adding a callback to handle the exception:

    cluster.on("exit", (worker) => {
        // notify all active workers
        for (const workerId in cluster.workers) {
            if (hasOwnProperty.call(cluster.workers, workerId)) {
                cluster.workers[workerId].send({
                    source: MESSAGE_SOURCE,
                    type: EventType.WORKER_EXIT,
                    data: worker.id,
                }, (err) => {
                    if (err) {
                        if (err.code == 'ERR_IPC_CHANNEL_CLOSED' || err.code == 'EPIPE') {
                            console.warn(`There was a synchronization problem. Wrong attempt to send a message to a disconnected worker`)
                            console.log(err);
                        } else {
                            throw err;
                        }
                    }
                });
            }
        }
    });

Steps to reproduce

1. Create a sample process.

process.on('SIGINT', () => {
    console.log(`Received SIGINT.  Shutting down.`);
    process.exit(0);
});

let i = 0;

async function run() {
    while (true) {
        await new Promise(resolve => setTimeout(resolve, 5000));
        console.log(`Number ${i++}.`);
    }
}

run().catch(error => {
    console.error('Error!', error);
    process.exit();
});

2. Delete pm2 and install @socket.io/pm2
3. Run the process in cluster mode

pm2 start test-process.js -i 3

4. Try to delete/stop/kill the processes.

pm2 delete all

After doing this, you will see the exceptions.

Env details

• node 16
• socket.io-cluster-adapter 0.1.0
• socket.io/pm2 latest

Hi, I think something went wrong during a recent upgrade.

The function createAdapter() from @socket.io/[email protected] returns (nsp: any) => ClusterAdapter where ClusterAdapter extends Adapter from [email protected]. However, server.adapter from [email protected] expects Adapter from [email protected]. There are large differences between these two classes.

Type 'ClusterAdapter' is missing the following properties from type 'Adapter': _encode, persistSession, restoreSession ...... 

As per socket io docs for cluster adapter https://socket.io/docs/v4/cluster-adapter io is only defined in workers, Can i emit events from master process.

I am trying to make one to one chat with fcm, so I want to check if two users are in the same room or not so i know if the user is in the one to one chat room page or not so i can determine whether to send a notification or not.

io.sockets.adapter.rooms.get(roomID)

It returns only connected sockets from the same instance!
@darrachequesne Could you help please?

Would a combination of Cluster Adapter and inter-server adapters like Redis Adapter be possible? See diagram below.

I am facing an error when fetching sockets with the .fetchSockets function. I'm using cluster-adapter + sticky + pm2 to manage workers.

Code snippet that calls the fetchSockets() function:

const sockets= await io
          .in(`${plataform}-${client}`)
          .fetchSockets();
          
//In other line          
const sockets = (
          await io
            .in(`${plataform}-${client}-${userId}`)
            .fetchSockets()
        )[0];
```
You have triggered an unhandledRejection, you may have forgotten to catch a Promise rejection:
Error: timeout reached: only 4 responses received out of 5
at Timeout._onTimeout (/opt/server/node_modules/@socket.io/cluster-adapter/dist/index.js:358:28)
at listOnTimeout (node:internal/timers:573:17)
at process.processTimers (node:internal/timers:514:7)


I've already tried everything. Furthermore, I already put a try catch around this promise