Utility methods with multiple nodes

[hossein-zare]

Hi,

I'm using some of the utility methods such as fetchSockets and disconnectSockets.
Are they available for multiple nodes with the Redis Adapter?

io.in('room-name').disconnectSockets();

By the way, Are socket objects read-only on other servers if we use fetchSockets?

[darrachequesne]

Hi! Yes, the Redis adapter is compatible with those methods.

By the way, Are socket objects read-only on other servers if we use fetchSockets?

On other servers, you'll get a object which exposes a subset of the methods of the Socket class:

const sockets = await io.fetchSockets();

for (const socket of sockets) {
  console.log(socket.id);
  console.log(socket.handshake);
  console.log(socket.rooms);
  console.log(socket.data);
  socket.emit(/* ... */);
  socket.join(/* ... */);
  socket.leave(/* ... */);
  socket.disconnect(/* ... */);
}

[hossein-zare]

Cool!

On other servers, you'll get a object which exposes a subset of the methods of the Socket class:
...

Is there any way to do something like socket.data.age = 25 for remote objects?

[darrachequesne]

In that case, you will have to use the serverSideEmit() method:

// on server A
io.serverSideEmit("setAge", id, age);

// on server B

io.on("setAge", (id, age) => {
  if (io.sockets.sockets.has(id)) {
    const socket = io.sockets.sockets.get(id);

    socket.data.age = age;
  }
});

Documentation: https://socket.io/docs/v4/server-instance/#serversideemit