ROS2 The Reliable Action Server

Hard Code Audit 0% pass rate
#action-server#cancel#is_cancel_requested#MultiThreadedExecutor#ros2

Practice the ROS2 The Reliable Action Server coding problem in Code Audit. Browser-based execution with automated grading — no local ROS install required. 0% of engineers pass this challenge.

An action server for long-running Fibonacci computations was deployed. Normal operation works correctly. However, clients report that when they cancel a long operation the client hangs forever — the server never sends a CANCELED status back.

The root cause: the execute_callback loop does not check goal_handle.is_cancel_requested. It keeps running to completion while the client waits indefinitely for the CANCELED acknowledgement.

Fix the server so that:

  1. A cancel request is acknowledged promptly (within 3 seconds of issuing it).
  2. Normal (non-cancelled) goals still complete successfully.

Frequently asked questions

What is the ROS2 The Reliable Action Server practice problem?

It is a hands-on Code Audit challenge on SimuCode where you implement and run ROS2 code in the browser with runtime-verified tests.

How do I practice ROS2 The Reliable Action Server online?

Open this page, sign in, and solve the problem in the built-in IDE. Your solution is graded against real ROS2 execution checks.

What skills does ROS2 The Reliable Action Server test?

This Hard problem focuses on action-server, cancel, is_cancel_requested skills used in robotics interviews and production systems.