The term “ility” is used in software architecture to describe quality concerns other than those that focus on the basic functionality and their correctness. In terms of DevOps, ilities correspond to questions such as:
- How well are these functionalities in the pipeline performing?
- Can you precisely repeat your DevOps operations when needed?
- How much time has passed between a business concept and its final release?
- How can different tools in a pipeline interoperate?
Even tough there are strong connections between a pipeline and the application – such as performance and recoverability – the pipeline itself must be analyzed for its ilities:
| Ilities | Quality Concnerns | Techniques to Achieve this Quality |
|---|---|---|
| Repeatability | The degree to which repeating the same operation is possible. | Maintain traces of activities. Version control everything. Use a CMDB to maintain parameters. Enforce where necessary. |
| Performance | The time and resources required to execute a DevOps operation. | Measure to determine bottlenecks in processes. Tear down an environmentwhenitisnotused. Perform as many operations as possible in the cloud, where resources can be freed if not used. |
| Reliability | The degree to which the DevOps pipeline and individual pieces of software within it maintain their services for defined periods of time. | Identify failure rates of different services. Mirror services with high failure rates. Detect failures as soon as possible through tools whose job is to monitor components for execution time outside the norm. |
| Recoverability | The degree to which a failed DevOps operation can be brought back to a desired state with minimal impacts to the application being operated on. | Build in exception handling in scripts. Provide information for monitoring services. Ensure that appropriate diagnostics are generated to enable faster debugging. |
| Interoperability | The degree to which different DevOps tools can usefully exchange information via interfaces in a particular context. | Select tools with stable interfaces and flexible scripting facilities. Ensure data models of various phases of the pipeline are consistent. |
| Testability | The ease with which the DevOps operation software can be made to demonstrate its fault through testing. | Use unit and integration test scripts for specialized otols. Coordinate test cases with monitoring rules. |
| Modifiability | The amount of effort required to change the DevOps software, processes, or the operation environment of an application. | Modularize scripts based on expected changes to the tools. Encapsulate operations actions into small modules that are loosely coupled with each other. |