apache/seatunnel

[Docs][Core] Add Javadoc to TaskExecutionService inner classes (cooperative/blocking execution model)

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#10546 opened on Feb 28, 2026

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help wanted

Description

Sub-issue of #10533

Scope

TaskExecutionService implements Zeta's dual-mode task execution: cooperative (work-stealing) for lightweight tasks and blocking (dedicated thread) for I/O-heavy tasks. Its inner classes — CooperativeTaskWorker, RunBusWorkSupplier, BlockingWorker, and TaskGroupExecutionTracker — implement this model but are entirely undocumented.

File

seatunnel-engine/seatunnel-engine-server/src/main/java/org/apache/seatunnel/engine/server/TaskExecutionService.java

Methods to document

Class / Method Line What to explain
submitThreadShareTask(...) 210 Routes cooperative (non-blocking) tasks into the shared work-stealing queue
submitBlockingTask(...) 235 Launches a dedicated thread per blocking task; why blocking tasks must not share threads
deployTask(TaskGroupImmutableInformation) 276 Deserializes task group; loads connector classes; starts thread-share or blocking tasks based on task type
notifyTaskStatusToMaster(...) 442 Reports per-task status changes to CoordinatorService via Hazelcast operation
CooperativeTaskWorker (class) 731 Work-stealing cooperative executor; exclusiveTaskTracker for single-task phases; loop structure
CooperativeTaskWorker.run() 753 Task-stealing loop; transitions between exclusive and shared task execution; yield on empty queue
RunBusWorkSupplier.runNewBusWork(boolean) 849 Creates new CooperativeTaskWorker threads on demand when queue pressure is detected
BlockingWorker.run() 667 Dedicated-thread lifecycle: init → call → done; status notification on completion or exception
TaskGroupExecutionTracker.taskDone(Task) 928 All-tasks-complete detection (countdown latch pattern); triggers group-level completion and resource cleanup
TaskGroupExecutionTracker.exception(Throwable) 901 First-exception-wins: records the first failure and cancels all sibling tasks in the group

How to contribute

  1. Fork the repo and create a branch
  2. Add Javadoc to the methods above
  3. Run ./mvnw spotless:apply and ./mvnw -q -DskipTests verify
  4. Open a PR with title: [Docs][Core] Add Javadoc to TaskExecutionService inner classes

Contributor guide

Tech stack
java
Domain
documentation
Issue type
documentation
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-2 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
fresh
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
Java basicsFamiliarity with JavadocUnderstanding of cooperative vs blocking execution
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
70
Research direction
Examine TaskExecutionService.java at seatunnel engine/seatunnel engine server/src/main/java/org/apache/seatunnel/engine/server/TaskExecutionService.java. Focus on the inner classes CooperativeTaskWorker, RunBusWorkSupplier, BlockingWorker, and TaskGroupExecutionTracker, as well as methods like submitThreadShareTask, submitBlockingTask, deployTask, and notifyTaskStatusToMaster. Read existing comments and code to understand the dual mode execution model. Look at linked issue #10533 for context. Review any existing PRs or comments for guidance on Javadoc style expected by the project.