Why you should use the system ready project
Error reporting and root cause analysis
When a system fails to become ready after a certain amount of time, the follow up question is : “What is wrong?”. So the framework also provides a way for each system check to report back information about errors.
One typical error is that a DS component does not come up because some mandatory dependency is not present. This dependency can be a configuration or maybe a service reference. In many cases, a trivial error like a missing configuration for a low level component can cause a lot of other components to fail to register. The root cause analysis allows traversing the trees of components and to narrow the reason for the system not being ready to a minimal number of possible causes for the failure state.
Typical use cases for the system ready check ordered by the phase of the development cycle.
- Coarse check of a pax exam based setup before letting the actual junit tests work on the system
- Determining the root cause of a pax exam based setup not starting
- Starting system tests as soon as a system is ready for the tests to proceed
- Determining the root cause for an OSGi based system not starting up
- Signaling when a system is ready after an upgrade so that it can receive traffic in the case of blue / green deployments
- Periodic Ready health checks for system and signaling this state to monitoring systems
- Container automation and driving autopilot container deployments.
Added value when using the system ready framework
- Increased deployment resilience as deployments are checked before being exposed
- Faster deployments / upgrades by replacing fixed, error-prone waits with ready based waits
- Lower bug tracking efforts in tests as root causes are easier to find
- Configurability of when a certain deployment is considered ready (e.g. after content sync with an external service)