Introducing Miranda: How Miranda Works

In preparation for a talk I'm giving at DOSUG I'm going to post my thoughts as they develop.

So Miranda looks like something you might be interested in, but how does it work?

Mirada sits in front of your web service and accepts POST/PUT/DELETEs on its behalf.  It then sends those events to your web service when it is up.

When a client sends a message to Miranda that is called an Event.  The end point that they send the POST/PUT/DELETE to is called a Topic.   An Event is delivered to a client as part of a subscription. When Miranda gets a 200 response as a result of sending an Event to a client, it records it as a Delivery.  All these things are set up with Users.

Before doing anything, a User must login to the system and establish a Session.

Miranda operates as a cluster of nodes.  To do anything, a qurom of 2 nodes needs to be established. Each Topic can have different rules about when to recognize an Event.  The default policy is after Miranda receives a POST/PUT/DELETE and has forwarded the event to a qorum of other nodes, it responds to the client, telling them that it received the Event.

At the same time that a node is telling the other nodes about an Event, it writes the Event to the persistent store.

Events are kept for a configurable period of time but the default is a week.  Deliveries are also kept for a configurable period of and this also defaults to a week.