Unhandled error event

[mathiask88]

Hey,
I implemented a redis adapter in this way

var socketioPub = m_redis.createClient(null, null, { detect_buffers: true });
socketioPub.on('error', function (err) { ... });
var socketioSub = m_redis.createClient(null, null, { detect_buffers: true });
socketioSub.on('error', function (err) { ... });
io.adapter(m_socketio_redis({ pubClient: socketioPub, subClient: socketioSub }));

So if the redis server e.g. is not running I can handle that error, but I get an unhandled error event from https://github.com/Automattic/socket.io-redis/blob/master/index.js#L73

[...]
  function Redis(nsp){
    Adapter.call(this, nsp);

    var self = this;
    sub.psubscribe(prefix + '#*', function(err){
      if (err) self.emit('error', err); <--------------------------------
    });
    sub.on('pmessage', this.onmessage.bind(this));
  }
[...]

because there is no event listener attached and I see no way to attach one from the outside. Any ideas?

Best regards!

[rauchg]

The adapter inherits from Emitter, so simply attach an error listener on the emitter instance.

[yaroshevych]

@guille, could you please advise on valid syntax for 'error' event. I can't find any working solution.

[rauchg]

Attach it on the adapter instance? On the object you pass to io.adapter

[yaroshevych]

Guillermo, thanks for your feedback, unfortunately it doesn't work with v. 0.1.3. Here is my code:

var redis = require('socket.io-redis');
var redisAdapter = redis({ host: 'abc', port: 12345 });
redisAdapter.on('error', function(err) {});
io.adapter(redisAdapter);

There is no 'on' method in redisAdapter object. Here is error:

   redisAdapter.on('error', function(err) {});
                 ^
TypeError: Object function Redis(nsp){
    Adapter.call(this, nsp);

    var self = this;
    sub.psubscribe(prefix + '#*', function(err){
      if (err) self.emit('error', err);
    });
    sub.on('pmessage', this.onmessage.bind(this));
  } has no method 'on'

[mathiask88]

Try redisAdapter.prototype.on('error', function(err) {}); that worked for me. But it feels a bit strange to edit the prototype...

[yaroshevych]

It's not working for me. When I kill Redis server, whole app crashes:

events.js:72
        throw er; // Unhandled 'error' event

[peteruithoven]

I'm having the same issue, please reopen.
The emit in the psubscribe callback is throwing an error, which can't be catched in a good way.
https://github.com/Automattic/socket.io-redis/blob/master/index.js#L73
I did add an error event handler:

var adapter = io.adapter(socketIORedis({  key: 'socket.io-redis-experiment',
                            pubClient: pub,
                            subClient: sub}));
adapter.on('error',function(err) {
  debug('adapter error: ',err);
});

[peteruithoven]

Adding a error listener on self, just before sub.psubscribe solves the unhandled error...

self.on('error',function(err) {
  console.log("socket.io-redis inside error handler: ",err);
});

Maybe the right instance reference isn't returned from the require?

[peteruithoven]

Putting a listener on adapter.prototype actually works... That's far from intuitive...
Example:

var adapter = socketIORedis();
adapter.prototype.on('error',function(err) {
  debug('adapter error: ',err);
});
io.adapter(adapter);

[peteruithoven]

I think I understand the problem, require('socket.io-redis') returns a "class" and every namespace creates it's own adapter instance from this.

[emidiocroci]

I tried the solution suggested by @peteruithoven but no luck... The error is still thrown causing a crash of the application. Is there some news about this issue?

[peteruithoven]

@emidiocroci, did you also try adding error listeners to the pub and sub clients?