[BUG] /chaosmonkey/assaults/runtime/attack does not respond when killApplicationActive is true

[blackr1234]

Expected Behavior

Endpoint /chaosmonkey/assaults/runtime/attack should respond with 200 OK when killApplicationActive is set to true.

---

Current Behavior

There is no reply from the server, i.e. curl: (52) Empty reply from server when using cURL.

---

How to reproduce

Call below endpoints in order:

curl localhost:8080/actuator/chaosmonkey/assaults -X POST -d "{ \"killApplicationActive\": true }" -H "Content-Type: application/json"
curl localhost:8080/actuator/chaosmonkey/assaults/runtime/attack -X POST

---

Project details

• Parent: spring-boot-starter-parent 3.2.4
• spring-boot-starter-web (managed version)
• spring-boot-starter-actuator (managed version)
• chaos-monkey-spring-boot 3.1.0

---

Root cause

• In the KillAppAssault#attack method, it calls SpringApplication.exit(context, () -> 0) to shut down Spring Boot.
  • This line will block until Spring Boot completes shutdown.
• Spring Boot will stop all active requests as part of the shutdown routine.
• Since the shutdown is being commenced within a request, Spring Boot can't proceed.
  • In the case of a graceful shutdown, Spring Boot keeps waiting, and when the grace period ends, it terminates all requests if they are still around.
  • In the case of an immediate shutdown (default), Spring Boot immediately terminates all requests.
• That's why the /chaosmonkey/assaults/runtime/attack request never responds when it needs to kill the app.

---

Additional reference

In addition, if we check how Spring Boot's own /actuator/shutdown is implemented, we can see that it uses a new thread to perform the shutdown (ConfigurableApplicationContext#close).

See: ShutdownEndpoint.java - line 49