The Unique Complexity of Testing in Systems Programming
September 3, 2018
Followers of this blog know that programming system software is not straightforward. Because modern apps run on system software, ensuring high speed and performance is a key mandate. Unlike applications programming which is comparatively easier, systems programming developers must have a thorough knowledge of the hardware including memory, OSes, and integration capabilities. It, of course, follows that testing in systems programming is equally challenging. Due to limited resources and the hardware dependency, developers need to be extremely skilled to identify bugs, determine their root-cause, and resolve them in time.
Systems programming challenges
First, a refresher, and do feel free to skip ahead if you’ve read as much in our earlier blog. Although systems programming is a critical aspect of software development, it requires extreme hardware knowledge and capacity planning in addition to understanding frequent software system upgrades, installation scripts, integration testing, and system-wide performance tuning. This makes the entire process extremely challenging:
- Since system software is often the foundation of dynamic and complex applications which are almost invisible to the end-user, client interfaces are fairly limited.
- The absence of an abstraction layer makes coding extremely challenging.
- The likely presence of console-based applications or command line interfaces is extremely high
- Since inter-component interfaces are rich and complex, knowledge of platform-specific APIs is critical.
- System software is highly dependent on the hardware; hence deep hardware knowledge is also required.
- The absence of advanced algorithms compels programmers to manage the entire development process on their own.
Ok, that settled, now on to why the testing is so challenging.
Complexity of testing
Testing is a crucial aspect of any product. Although software development testing is also complex in its own way, systems programming takes testing to an entirely different level of complexity.
- No Physical Access to Hardware: Since hardware plays an important role in systems programming, no physical access to the hardware is one of the biggest challenges that makes testing extremely complex. Testing is usually performed remotely through distant servers as testers do not have physical access to hardware.
- Limited Resources: Since system software generally has limited resources over and above the application it is supposed to run, specifically limited storage space and speed – the testing tool faces a difficult trade-off of either having test data on the development platform or having test data interpreted by the test driver on the target platform.
- Hardware Dependency: Because systems programming is highly dependent on hardware, testing might list out defects that are related not just to the software, but also to the hardware. In addition, although tested software may work well with one variant of the hardware, it might not with another.
- Timing Constraints: Since the accuracy of system software depends, to a large extent, on the time at which the results are produced, if timing constraints of the system are not met, the chances of system failure are extremely high. Therefore, testing timing constraints is just as important as testing functional behavior.
- Different Application Development and Execution Platforms: Since systems programming is usually done on a platform different from the one on which the application is deployed, it will not encompass necessary hardware components such as keyboards and networking. From the development platform, testing tools need to offer access to the execution platform in the most transparent but efficient way possible – such that it is hidden from the user.
- Defects are Hard to Reproduce: Since it is tough to reproduce and recreate defects in systems programming testing, the probability of occurrence of every defect has to be assumed higher than that of normal software testing. Add to that the need to collect as much information as possible to discover the foundation of the defect. This is difficult given the extremely constrained nature of troubleshooting capabilities.
- Growing Variety of Execution Platforms: Since execution platforms can range from tiny 8-bit micro-controllers to large, distributed and networked systems, every platform requires a specific set of testing tools that can efficiently and accurately test for issues. Because multiple platforms could be used within the same system software, testers need access to and knowledge of a large set of testing tools that can adapt to emerging platform architectures in time.
- Limited Software Updates: Since software updates in systems programming are fairly limited, manually finding bugs and rectifying them in every software version is a tough undertaking. This makes it extremely important for developers to pay close attention to the build and deployment process to ensure the minimum number of defects.
- Emerging Standards: Much of system software is used in safety-critical systems across industries like nuclear, medical, and avionics, system failure is just not an option. With emerging standards around zero-failure objectives, developing safety-critical software is no longer an option, but a requisite – which puts a lot of pressure on those testing the systems software.
Overcome Challenges to Ensure Success
Since systems programming lies at the very heart of high performing mobile and web applications, there is a clear and present need for developers and testers to continuously drive efforts to improve the quality of system software. With limited programming facilities and resources, this is extremely tough. However, with the right skills and attitude, and by using the appropriate tools and enabling automation, you can ensure that defects are identified and rectified in time and that the software uses the hardware its fullest potential –and that is essential to ensure product success.