zaqar/doc/source/index.rst
Flavio Percoco 4ef3b28f92 Move the module reference to the top
Instead of having to scroll down to the bottom to read the module
reference, it'd be better to make it available for developers before
they get into the "how contribute section". This way, we can keep zaqar
and openstack sections grouped respectively.

Change-Id: I8c5e39e09352ba13b3fe2bf2d04a1dac93ac6509
2014-10-03 11:44:12 +02:00

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Welcome to the Zaqar developer documentation!

Zaqar is a multi-tenant cloud messaging and notification service for web and mobile developers.

The service features a ReST API, which developers can use to send messages between various components of their SaaS and mobile applications, by using a variety of communication patterns. Underlying this API is an efficient messaging engine designed with scalability and security in mind.

Other OpenStack components can integrate with Zaqar to surface events to end users and to communicate with guest agents that run in the "over-cloud" layer.

Note

This documentation is generated by the Sphinx toolkit and lives in the Zaqar project source tree. Additional draft and project documentation regarding Zaqar and other components of OpenStack can be found on the OpenStack Wiki, as well as in the user guides found on docs.openstack.org.

Key features

Zaqar provides the following key features:

  • HTTP-based messaging API
  • Multi-tenant design based on Keystone project IDs
  • Support for several common patterns including event broadcasting, task distribution, and point-to-point messaging
  • Component-based architecture with support for custom backends and message filters
  • Efficient reference implementation with an eye toward low latency and high throughput (dependent on backend)
  • Highly-available and horizontally scalable

Project scope

The Zaqar API is data-oriented. That is, it does not provision message brokers and expose those directly to clients. Instead, the API acts as a bridge between the client and one or more backends. A provisioning service for message brokers—however useful—serves a somewhat different market from what Zaqar is targeting today. With that in mind, if users are interested in a broker provisioning service, the community should consider starting a new project to address that need.

Design principles

Zaqar, as with all OpenStack projects, is designed with the following guidelines in mind:

  • Component-based architecture. Quickly add new behaviors
  • Highly available and scalable. Scale to very serious workloads
  • Fault tolerant. Isolated processes avoid cascading failures
  • Recoverable. Failures should be easy to diagnose, debug, and rectify
  • Open standards. Be a reference implementation for a community-driven

Concepts

glossary

Modules reference

Zaqar is composed of two layers:

transport storage

The transport drivers are responsible for interacting with Zaqar clients. Every query made by clients is processed by the transport layer, which is in charge of passing this information to the backend and then returning the response in a format understandable by the client.

The storage drivers are responsible for interacting with the storage backends and, that way, store or retrieve the data coming from the transport layer.

In order to keep these layers decoupled, we have established that checks should be performed in the appropriate layer. In other words, transport drivers must guarantee that the incoming data is well-formed and storage drivers must enforce their data model stays consistent.

Setting up a development environment

development-environment

Your first patch and your first review

first_patch first_review

Running and writing tests

running_tests test_suite

Other resources

launchpad gerrit jenkins

API reference

api/autoindex

Indices and tables

  • genindex
  • modindex
  • search