Health Checks

Health Checks to analyze down times of applications

Health Checks

Health checks provide real-time visibility into the impact of chaos scenarios on application availability and performance. They run continuously in the background throughout the chaos run, detecting outages, measuring downtime duration, and recording results in telemetry.

Krkn supports multiple health check types through a plugin-based architecture:

  • http_health_check — monitors HTTP/HTTPS endpoints (documented on this page)
  • virt_health_check — monitors KubeVirt VMI SSH connectivity (see Kube Virt Checks)
  • Custom plugins — extend the system with your own health check logic (see Health Check Plugins)

Health checks are configured in the config.yaml under the health_checks key.

The http_health_check plugin periodically checks the provided URLs based on the defined interval and records the results in Telemetry. The telemetry data includes:

  • Success response 200 when the application is running normally.
  • Failure response other than 200 if the application experiences downtime or errors.

This helps users quickly identify application health issues and take necessary actions.

Sample health check config 

health_checks:
  interval: <time_in_seconds>                       # Defines the frequency of health checks, default value is 2 seconds
  config:                                           # List of application endpoints to check
    - url: "https://example.com/health"
      bearer_token: "hfjauljl..."                   # Bearer token for authentication if any
      auth:                                         
      exit_on_failure: True                         # If value is True exits when health check failed for application, values can be True/False
      verify_url: True                              # SSL Verification of URL, default to true
    - url: "https://another-service.com/status"
      bearer_token:
      auth: ("admin","secretpassword")              # Provide authentication credentials (username , password) in tuple format if any, ex:("admin","secretpassword")
      exit_on_failure: False
      verify_url: False  
    - url: http://general-service.com
      bearer_token:
      auth:
      exit_on_failure:  
      verify_url: False

Sample health check telemetry 

"health_checks": [
            {
                "url": "https://example.com/health",
                "status": False,
                "status_code": "503",
                "start_timestamp": "2025-02-25 11:51:33",
                "end_timestamp": "2025-02-25 11:51:40",
                "duration": "0:00:07"
            },
            {
                "url": "https://another-service.com/status",
                "status": True,
                "status_code": 200,
                "start_timestamp": "2025-02-25 22:18:19",
                "end_timestamp": "22025-02-25 22:22:46",
                "duration": "0:04:27"
            },
            {
                "url": "http://general-service.com",
                "status": True,
                "status_code": 200,
                "start_timestamp": "2025-02-25 22:18:19",
                "end_timestamp": "22025-02-25 22:22:46",
                "duration": "0:04:27"
            }
        ],

See Also

Last modified March 23, 2026: health check plugins (6259ff7)