Monday, 4 November 2013

IronMQ - Message Queue in the cloud

Why didn't anybody think of it before!

The advent of cloud services are breaking apart the server-centered thinking: with the cloud - or in the cloud - all Internet services are close to each other. The trunk line connections even between separate clouds provide fast enough access speed to actually start "picking" the services. Paas (Platform as a service) will give way to Saas (Software as a service), or maybe even "Service as a service". Selecting any Internet service will be possible if services are compatible enough and "close" enough.

Cloud makes the services close enough but it's not enough by itself. Distributed computing and application integration requires a reliable way for the applications to talk to each other, preferably without syncronization because in a real word (cloud/Internet) services and applications don't necessarily go at the same speed. One of the best ways to balance the sending and receiving is to use a message queue.

Until now message queues have been limited inside one server, with a few exceptions, such as IBM's Websphere MQ. And even then, the interface to the message queues has been via linkable system libraries, which binds them to platforms or even specific programming languages. And of course the message queue must have an available node, port or other connection point accessible from within the server. has changed that! If cloud makes services available to all applications, then there should be a message queue inside cloud - but outside servers. IronMQ is that messages queue; and its API is in line with most cloud services because it is a REST compatible API.

IronMQ is "Message queue as a service", the first of its kind. Customer may pay on a per-message basis which goes perfectly with the idea of Saas. For a hobbyist it's a heaven since the payments only start running after the first 10 million requests (REST calls). uses OAuth for user authentication, and access protocol is of course HTTPS. REST interface for a message queue is not the big innovation here; there is other message queues which also provide a REST interface to supplement their normal socket interface, or linkable library interface. What is an innovation is how well IronMQ is interacting in cloud/Internet environment: from a passive party (what a message queue by nature is) it turns into an active party via its "push queues". Push queue is a queue which "knows" who is going to read the messages. It simply means that the message is relayed to another HTTP (or HTTPS) endpoint. The subscriber does not need to keep polling the queue for new messages; it simply sets up an HTTP(S) server/reader and waits for the messages. Besides remote HTTP endpoints, messages can also be pushed to different queues or IronWorker,'s worker system.

IronMQ pushes the concept of push queues even further: it accepts messages pushed to it by the REST compatible method of Webhooks, user-defined HTTP callbacks. They are usually triggered by some event, such as pushing code to a repository or a comment being posted to a blog. When that event occurs the source site makes an HTTP request to the URI configured for the webhook. has three cloud services: IronMQ, IronWorker and IronCache (a key-value storage). All of them have a REST interface and excellent cloud-usability. Cloud applications are often parts of integration systems. But the integration itself has been difficult because most integration tools, such as message queues, are running "inside" servers and are good at providing "internal" services.'s services are "between" servers and they are accessible by the most widely used REST protocol, HTTP.