TaskCluster is a set of components that manages task queuing, scheduling, execution and provisioning of resources. It was designed to run automated builds and test at Mozilla.
The diagram above illustrates how some of the most important taskcluster components interact. When a user submits a task-graph to the scheduler, it posts tasks to the queue, from where the tasks are executed by workers. All the while a provisioner launches worker nodes depending on how many pending tasks we have.
Below you'll see an illustration of the layers from task-graph to task to run on some worker node.
TaskCluster promises a consistent task execution environment.
This means, that if you submit the same deterministic task twice then you should get two consistent resolutions.