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Typical datacenter operations and processes involve taking multiple actions across various systems. To capture and automate these operations, EWC uses workflows. A workflow strings atomic actions into a higher level automation, and orchestrates their executions by calling the right action, at the right time, with the right input. It keeps state, passes data between actions, and provides reliability and transparency to the execution.
Just like any actions, workflows are exposed in the automation library, and can be called manually, or triggered by rules. Workflows can even be called from other workflows.
To create a workflow action, choose a workflow runner (Mistral or ActionChain), connect the actions in a workflow definition, and provide the usual action meta data.
ActionChain is EWC’s internal no-frills workflow runner. It provides a simple syntax to define a chain of actions, runs them one after another, passing data from one action to another until it succeeds or fails.
Use ActionChain when you want speed and simplicity.
Mistral is a dedicated workflow service, originated in OpenStack, integrated and bundled with EWC. With Mistral, you can define complex workflow logic with nested workflows, forks, joins, and policies for error handling, retries, and delays.
Use Mistral when you need power and resilience.
Orchestra is a new workflow engine, designed specifically for EWC. It is currently in public beta. In future this will replace both Action Chain and Mistral. With Orchestra, you can define simple sequential workflows or complex workflows with forks, joins, and sophisticated data transformation and queries.
Use Orchestra to test-drive the future of workflows.
Learn how to define and run workflows: