Implementation:Apache Dolphinscheduler ITaskExecutorEventListener Callbacks

Knowledge Sources	Apache DolphinScheduler
Domains	Distributed_Systems, Event_Processing
Last Updated	2026-02-10 00:00 GMT

Overview

Concrete tool for tracking task lifecycle state changes via the ITaskExecutorEventListener RPC interface with typed lifecycle event callbacks.

Description

ITaskExecutorEventListener is an @RpcService interface with seven @RpcMethod callbacks, one for each lifecycle event type. The worker calls these methods via RPC proxy to notify the master of state transitions. Each event carries the task instance ID and state-specific data. The master's implementation updates the workflow DAG, triggers downstream tasks on success, or handles failure/recovery.

Usage

The listener is implemented by the master server and registered as an RPC service. Workers call it via the standard RPC proxy mechanism (Clients.withService()). Application code does not call these methods directly.

Code Reference

Source Location

• Repository: dolphinscheduler
• File: dolphinscheduler-extract/dolphinscheduler-extract-master/src/main/java/org/apache/dolphinscheduler/extract/master/ITaskExecutorEventListener.java (L30-52)

Signature

@RpcService
public interface ITaskExecutorEventListener {

    @RpcMethod
    void onTaskExecutorDispatched(
        TaskExecutorDispatchedLifecycleEvent event);

    @RpcMethod
    void onTaskExecutorRunning(
        TaskExecutorStartedLifecycleEvent event);

    @RpcMethod
    void onTaskExecutorSuccess(
        TaskExecutorSuccessLifecycleEvent event);

    @RpcMethod
    void onTaskExecutorFailed(
        TaskExecutorFailedLifecycleEvent event);

    @RpcMethod
    void onTaskExecutorKilled(
        TaskExecutorKilledLifecycleEvent event);

    @RpcMethod
    void onTaskExecutorPaused(
        TaskExecutorPausedLifecycleEvent event);

    @RpcMethod
    void onTaskExecutorRuntimeContextChanged(
        TaskExecutorRuntimeContextChangedLifecycleEvent event);
}

Import

import org.apache.dolphinscheduler.extract.master.ITaskExecutorEventListener;

I/O Contract

Inputs

Name	Type	Required	Description
TaskExecutorDispatchedLifecycleEvent	Event DTO	Yes	Task accepted by worker
TaskExecutorStartedLifecycleEvent	Event DTO	Yes	Execution begun
TaskExecutorSuccessLifecycleEvent	Event DTO	Yes	Completed successfully
TaskExecutorFailedLifecycleEvent	Event DTO	Yes	Execution failed
TaskExecutorKilledLifecycleEvent	Event DTO	Yes	Task killed
TaskExecutorPausedLifecycleEvent	Event DTO	Yes	Task paused
TaskExecutorRuntimeContextChangedLifecycleEvent	Event DTO	No	Progress/log update

Outputs

Name	Type	Description
Updated task state	DB record	Task instance state updated in master's workflow DAG
Downstream triggers	Events	Ready downstream tasks queued for dispatch
Workflow completion	State change	Workflow marked complete when all tasks finished

Usage Examples

Worker Reporting Success

// In PhysicalTaskExecutor after successful execution
ITaskExecutorEventListener listener = Clients
    .withService(ITaskExecutorEventListener.class)
    .withHost(masterAddress);

listener.onTaskExecutorSuccess(
    TaskExecutorSuccessLifecycleEvent.builder()
        .taskInstanceId(taskInstanceId)
        .build()
);

Worker Reporting Failure

listener.onTaskExecutorFailed(
    TaskExecutorFailedLifecycleEvent.builder()
        .taskInstanceId(taskInstanceId)
        .build()
);

Related Pages

Implements Principle

• Principle:Apache_Dolphinscheduler_Task_Lifecycle_Event_Tracking