Error: node_redis command queue state error. If you can reproduce this, please report it.

[twmobius]

Hello,

Using this snippet:

var redis = require('redis');

var subscriber = redis.createClient();
var publisher  = redis.createClient();

subscriber.on('message', function(channel, data) {
  console.log(data);

  subscriber.unsubscribe('test');
});

subscriber.subscribe('test');

setTimeout( function() {
  publisher.publish('test', 'Testing', function() {
    console.log("Published");
  });

  subscriber.unsubscribe('test');
}, 1000);

Crashes node-redis. In theory if the channel is already unsubscribed redis should not try to unsubscribe it again (If I understand why the error happens)

Great job btw :) Thank you!

[jsolla]

I can confirm this bug.

My situation is:

I'm working on an application to notify realtime variables (temperature/humidity,etc) to web-browser clients, using node/socket.io/redis.

At my node code I've the following lines:

cliSocket.on('subscribe',function(msg)
{
    console.log("Subscription request:"+msg.channel);

    // Only one subscription allowed per client
    redisCli.punsubscribe("*");

    // Subscribe to new channel
    redisCli.subscribe(msg.channel);
});

Test steps:

1. Start node server with the depicted code....
2. Open a browser and connect to the node server
3. Browser sends a "subscribe" command using socket.io
4. Redis_cli crashes.

The problem is this line: redisCli.punsubscribe("*"); if I comment out this line, it no longer crashes.

If more tests are needed, just let me know.

[DTrejo]

To prevent this from crashing redis, add the following. The command state queue error is caused by the double unsubscribe (or trying to unsubscribe when you are not subscribed to anything, in @jsolla's case?). Not really sure if there's a good way to fix this in node_redis, if either of you would like to submit pull requests, I would be happy to look them over and most-likely merge.

@jsolla: you may not need to supply the *? http://redis.io/commands/punsubscribe

Cheers and thanks!

D

subscriber.on('error', function(e) {
   console.log('subscriber', e.stack); 
});

publisher.on('error', function(e) {
   console.log('publisher', e.stack); 
});

[BridgeAR]

This is finally fixed on master...