com.amazon.kepler.tasks

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Interfaces

• ITaskResult — The ITaskResult interface contract is used to post updates about Task execution and to finally indicate success or failure to active Task Observers. It is returned as param to ITaskObserver::onUpdate. The Task Result is delivered to all observer objects registered with the Task Manager at the time a result is posted. Task Results are not cached by the Task Manager.
• ITaskResultBuilder — The ITaskResultBuilder is used to create an object that conforms to ITaskResult. The ITaskResult can then be submitted to post updates about Task execution and to indicate success or failure to the TaskManager.
• ITaskObserver — The ITaskObserver allows callers to get notified of updates in Task execution. It can signal intermediate results, final results as well as errors returned by the Task handler and errors in execution of the Task. Task Observers offer the convenience to react to a Task Result immediately. However, they are not a substitute for persisting results in use cases where the result must be consumed by another part of the app that may not be running at that instant. Note that ITaskObserver callbacks may execute on a thread which may be different from the main thread of the app.
• ITaskStatus — The ITaskStatus provides information about a submitted Task.
• IRetryPolicy — The IRetryPolicy is the retry preference when Task fails. Use the IRetryPolicyBuilder to create an object that conforms to IRetryPolicy.
• IRetryPolicyBuilder — The IRetryPolicyBuilder allows callers to express retry preferences for Task failures. The retry policy consists of a minimum delay between successive retries and a count of retries to perform. A Task is marked TaskState::FAILED if retries are exhausted. It remains in TaskState::PENDING as it waits for the next execution opportunity.
• ITaskRequest — The ITaskRequest describes the execution parameters of a Task. Use the ITaskRequestBuilder to create an object that conforms to ITaskRequest.
• ITaskRequestBuilder — The ITaskRequestBuilder allows callers to encode execution parameters of a Task. A TaskRequest consists of the name of the Task handler to run, an unique id associated with the submission, zero or more constraint sets and an optional persistence flag.
• ITaskRegistration — The ITaskRegistration represents a submitted task and offers operations to update, query information, and attach observers to the submitted task.
• TaskExecutionInfo — Identification of a running Task instance delivered to its Task lifecycle component.
• ITaskManager — The ITaskManager offers operations for submitting and cancelling of Tasks as well as querying status.
• ITaskManager2 — Extension of ITaskManager with operations scoped to a running Task instance.
• ITimeProperties — The ITimeProperties describes the time constraint for task execution. Use the ITimePropertiesBuilder to create an object that conforms to ITimeProperties.
• ITimePropertiesBuilder — The ITimePropertiesBuilder allows callers to create an instance ITimeProperties. The constraint can be a combination of a delay or start time, an execution window and a repetition interval. A time window defines a specific start time and a duration inside of which task execution must begin.
• IKeplerTasksModule — The IKeplerTasksModule is the top-level interface that can be discovered via Omnikit. The interface can be used to build objects implementing other interfaces in this package that are required to be non singleton.

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Enumerations

• TaskState — TaskState identifies the state of the submitted Task.
• TaskCompletionStatus — TaskCompletionStatus identifies the outcome of Task execution.

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Exceptions

• TaskNameExistsError — This exception is only thrown when a user submits a task with a name that is already used. Names are unique per VPKG meaning that there can only be one task scheduled with a specific name.