| # 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. | |
| ## Use cases | |
| Typical use cases for the system ready check ordered by the phase of the development cycle. | |
| ### Development | |
| * 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 | |
| ### QA | |
| * 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 | |
| ### Deployment | |
| * Signaling when a system is ready after an upgrade so that it can receive traffic in the case of blue / green deployments | |
| ### Production | |
| * 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) |