publish-subscribe

Trying to create two clients; one is pub/sub, the other is a standard connection. Is this not possible? There must be a way to abstract this to work :) Basically, if I do a get key after running test.js, all I see is 'valueBefore'. The output: node test.js Reply: OK /Users/franklovecchio/Desktop/development/node/node_modules/redis/index.js:487 throw new Error("Connection in pub/sub mode, only pub/sub commands may ^ Error: Connection in pub/sub mode, only pub/sub commands may be used at RedisClient.send_command (/Users/franklovecchio/Desktop/development/node/node_modules/redis/index.js:487:15)

My mental model was that of a 'chat', where I am subscribed to a certain channel and I can publish messages to this channel. Since pub/sub is asynchronous, the published message could appear at any time, including when you are expecting the response to a command. Although redis is single threaded, which normally prevents that sort of thing, network latency can cause some interesting effects - depending on the content of the messages, you could receive a valid response to a command before the server has actually received it. That said, you could probably use a single connection if you really

Why does Redis , a datastore, have Pub/Sub features? My first thought is that it's the wrong layer to implement such a thing. But maybe I need to think outside the box. Redis is defined as data structure server. Redis provides multiple functionality like memcache, queue, pubsub etc. This is very useful for a cloudapp/webstack where 3 components RabbitMQ(queuing) + XMPP(pubsub) + Memcache can be currently replaced with redis. Queuing is not as feature rich as RabbitMQ though. That would be true if it was about feeds for end users to subscribe to. Actually it's closer to the concept of events or

If I were to design a huge distributed system whose throughput should scale linearly with the number of subscribers and number of channels in the system, which would be better ? 1) Redis Cluster (only for Redis 3.0 alpha, if its in cluster mode, you can publish in one node and subscribe in another completely different node, and the messages will propagate and reach you). The complexity of Publish is O(N+M) , where N is the number of subscribed clients and M is the number of subscribed patterns in the system, but how does it scale when in a Redis Cluster ? I accept educated guesses on this. 2)

I use the node application purely for socket.io channels with Redis PubSub, and at the moment I have it spread across 3 machines, backed by nginx load balancing on one of the machines. I want to replace this node application with a Phoenix application, and I'm still all new to the erlang/Elixir world so I still haven't figured out how a single Phoenix application can span on more than one machine. Googling all possible scaling and load balancing terms yielded nothing. The 1.0 release notes mention this regarding channels: Even on a cluster of machines, your messages are broadcasted across the

RabbitMQ's Channel#basicConsume method gives us the following arguments: channel.basicConsume(queueName, autoAck, consumerTag, noLocal, exclusive, arguments, callback); Giving us the ability to tell RabbitMQ exactly which queue we want to consume from. But Channel#basicPublish has no such equivalency: channel.basicPublish(exchangeName, routingKey, mandatory, immediateFlag, basicProperties, messageAsBytes); Why can't I specify the queue to publish to here?!? How do I get a Channel publishing to, say, a queue named logging ? Thanks in advance! Basically queues can be binded to an exchange based