Optional message that can be used to make sure the executor's connection is still alive and to prevent any possible network intermediaries from marking the connection as stale (when there are no other messages being sent).

See comments above on `Event::Type` for more details on this enum value.

Received periodically to make sure the connection is alive and to prevent any possible network intermediaries from marking the connection as stale (when there are no other messages being sent).

Received when the agent asks the executor to shutdown/kill itself.

This must be the first enum value in this list, to ensure that if 'type' is not set, the default value is UNKNOWN.

* Executor call API.

Sends arbitrary binary data to the scheduler.

Request to subscribe with the agent.

Notifies the scheduler that a task has transitioned from one state to another.

* Executor event API.

Received when the agent acknowledges the receipt of status update.

Received in case the executor sends invalid calls (e.g., required values not set).

Received when the scheduler wants to kill a specific task.

Received when the framework attempts to launch a task.

Received when the framework attempts to launch a group of tasks atomically.

Received when a custom message generated by the scheduler is forwarded by the agent.

First event received when the executor subscribes.

Possible call types, followed by message definitions if applicable.

A CallOpt is a functional option type for Calls.

Possible event types, followed by message definitions if applicable.