What is software resilience testing?
Software testing, in general, involves many different techniques and methodologies to test every aspect of the software regarding functionality, performance, and bugs.
Resilience testing, in particular, is a crucial step in ensuring applications succeed in real-life conditions. It really is an area of the non-functional sector of software assessment that also contains compliance testing, strength testing, load assessment, recovery testing amongst others.
As the word implies, resilience in software describes its potential to stand up to stress and other challenging factors to keep doing its core functions and prevent lack or even loss of data. Or as identified by IBM:
“Software solution resiliency refers to the ability of a solution to absorb the impact of a problem in one or more parts of a system, while continuing to provide an acceptable service level to the business.”
Since you can’t ever ensure a 100% rate of avoiding inability for software, you should provide functions for recovery from disruptions in your software. By putting into action fail-safe capacities, you’ll be able to typically avoid data damage in case there are crashes also to restore the application form to the previous working state prior to the crash with reduced impact on an individual.
One way of increasing the resilience of software and solutions is by hosting them on cloud servers, we at Top Level Traffic provide this service thus minimizing the chance of failures to the internal system and choosing a much more resilient cloud architecture. While disruptions do occur on the cloud level as well, the cloud operators usually have sophisticated resilience and recovery systems in place like we do to prevent such problems arising.
Some examples of how software resilience testing is done would be:
Resilience testing at Netflix
A great example of how resilience testing can be done successfully on cloud level is Netflix and its so-called Simian Army. Even though all of the Netflix services are hosted on Amazon Web Services’ state of the art cloud servers with cutting edge hardware, the company realized that the sheer scale of their operations makes failures unavoidable.
To prepare for these failures, Netflix developed their own tool to create random disruptions to the system and tested it for resilience. The tool was designed to simulate “unleashing a wild monkey with a weapon in your data center (or cloud region) to randomly shoot down instances and chew through cables ” and was aptly called Chaos Monkey. By identifying weaknesses in their systems, Netflix can then build automated recovery mechanisms to deal with them should they occur again in the future.
The tool is run while Netflix continues to operate its services, although in a handled natural environment and in ideal time frames. By only jogging Chaos Monkey during USA business a lot of time on weekdays, the business means that their engineers will have the utmost capacity for interacting with the disruptions and therefore servers are minimal in comparison to peak consumer use times.
After first successes, Netflix quickly developed additional tools to check other sorts of failures and conditions. Among these tools were Latency Monkey, Conformity Monkey, Doctor Monkey among others, collectively known as the Netflix Simian Army. Resilience evaluation with the Simian Army has since turned into a popular approach for a lot of companies, and in 2016 Netflix released Chaos Monkey 2.0 with upgraded UX and integration for Spinnaker. ( Great for us techies to play with 😀 )
Resilience Testing at IBM
To get a concept of how companies respond to different sorts of failures, we can look at how resilience evaluation is performed at IBM, where they identified two significant components of resiliency, the problem impact and the service level that is considered acceptable once the problem occurs.
Ideally, any inability could have no impact in any way on the buyer. Since that is impossible to attain, IBM is targeted on lessening that impact whenever you can. Should a machine that is the web host the machine or one of its components crashes, for illustration, the requests on the way compared to that machine would get redirected to some other machine instantly so keeping things running as smoothly as possible or at least as it can be to the users.
A far more dramatic event would be your failure of a whole data center, in which particular case
“all the work that was being processed by that data center is continued by another data center – again as transparently as possible to the users, although in the event of a catastrophic outage you should be prepared for a significant impact.”
The target at IBM is to reduce the impact and length of failures. For just a machine inability, this length is usually measured in minutes, while failing in a data facility might lead to disruptions of a long time. To create substantial resiliency test conditions, IBM uses the solution operational model where all the components of the solution to the problems as well as their interactions are identified. They then look at solution non-functional requirements to create a list of requirements to the solution such as response time, throughput and availability.
Wrapping it up.
With consumer expectations increasing, it is vital to ensure minimal disruptions to any service or software that enters the market these days especially that all important first launch of your online business or software start-up etc. While cloud hosting can go a long way in minimizing failures, resilience screening should still make up a significant part of overall software screening.
There are many different approaches for resilience screening. Using chaos engineering and the Netflix Simian Army can help discover unusual problem sources and potential weaknesses in the system’s architecture. It requires capacities for controlled screening though, and for many companies, a more structured and theoretical strategy like the one used by IBM makes sense.
Either way at Top Level Traffic, rest assured we take care of all this, to enable the best Digital Business Optimisation services for your Brand and company. Thanks for reading should you find value in this post please do not forget to give it a share or like and show your support so others may find value also in this post.
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