DevOps and the Application Life Cycle Model
DevOps is very useful in application development life cycle as it can tackle most of the common problems in an effective manner. In this regard the process which is much beneficial is continuous delivery. Continuous delivery brings together automated testing, continuous integration of complex systems and automated deployment. Particularly when the software is composed of many loosely coupled components, like in most software-as-a-service application, the testing phase which includes qualitative analysis, integration tests and deployment tests become more complex and requires much manual intervention in integrating components for next level. Automating such a task would be very helpful in faster software development and application life cycle.
By this customers can get functionalities more frequently and with less errors.
Some of the organizations uses amazing automation features and best practices to deploy thousands of tiny changes in the software everyday which may be helpful in larger releases. With frequent and rapid releases the software development process gets easier and more agile. Also applying large number of small changes instead of applying major big changes reduces risk and stress in the software development. Although applying large number of small changes seems a daunting task, it
avoids the risk of applying big changes and something big goes wrong. When applying small set of codes the errors or bugs can be easily identified and reduces the debugging time to the application.
Also in the above practice, we can isolate the repetitive and monotonous tasks and can automate them. By this lot of resources can be saved and can be used for other problems. Now the challenging task is to find them and automate them. These kind of automation is not same for all tasks and for all organizations. They are very unique to the set of problems and requires different set of tools with respective to the particular problem. For each set of task a system has to be build which can do all the boring stuffs from unit tests, integration tests etc.
When there is more automation, the software development process gets faster and also in a consistent manner. When people are supposed to repetitive and boring tasks they tend to make errors. But the automation systems is more reliable in doing these kind of tasks. The most important factor in continuous delivery is automated integration as it is one of the much needed activity for testing whether the build succeeded. As soon as a build is released, the automation system can tell whether all loosely coupled components are working properly and whether the system is working well, on the whole. This saves a lot of time as integrating such a complex software would take much time and more manual work.
When making changes in smaller level, we can exactly understand the impact of the change in the component. We can also identify the bad build and the cause for the bad build and can escalate to the bug fixing team swiftly. This avoids a lot of risk factors and provide more agility in QA. When using continuous delivery the changes are tested not just at the unit level, the automation system can integrate the software and test it completely.
One major problem without automation in continuous delivery is the waiting time needed to assemble the loosely coupled components and inspecting the change. One more disadvantage in this approach is that the smaller components may work well and they may fail when they integrated into a big system as per the requirements. Identifying such a problem is a painful task. Many companies like Openstack relies on automated integration to test their components on each build. This is really
essential because thousands of commits are done in a day and they need to validate each and every build before release. Doing such a huge task manually is not possible in real world.
In business perspective it takes a particular time to get an idea into production. If it takes longer than the appropriate time for a particular development activity then the business process is not agile and it is not following the best practices. One strong fact is that the organization can close this gap and realize the true value for Agile development by incorporating DevOps processes and tools like ITIL in their software development life cycle.
The whole point of agile development is to remove slow and monolithic development by breaking down large tasks into smaller ones and speed up the development process. By splitting up the processes, the particular module can be sent to the next process in SDLC and so developers, testers, QA and operation specialists can all work together. This is impossible if the task is processed as whole because one team needs to wait for other it slows up the development process.