Workflow service overview¶

Mistral is a workflow service that enables setting up and scheduling tasks and task relations that have to be executed in a particular order, called workflows. During execution, Mistral handles state management, correct execution order, parallelism, synchronization and high availability.

Mistral can be used, for example, for Cloud Cron-style task scheduling, Cloud Environment Deployment, handling long-running business processes, managing BigData analysis and tasks, and live migration.

The Workflow service consists of the following components:

Mistral API service

Provides a REST API for operating and monitoring workflow executions.

mistral-dashboard service

Mistral Dashboard is a Horizon plugin.

Mistral Engine service

Controls workflow executions and handles their data flow, places finished tasks in a queue, transfers data from task to task, and deals with condition transitions, and so on.

Mistral Executor service

Executes task actions, picks up the tasks from the queue, runs actions, and sends results back to the engine.

Mistral Notifier service

python-mistralclient

Python client API and Command Line Interface.

mistral-lib A library to support writing custom Mistral actions.