The extreme variety of users and related devices on which an application runs poses additional challenges to programmers. It’s no longer just a matter of empirically evaluating the efficiency of a code in terms of functionality and reliability: to avoid even significant impacts on service quality, it’s essential to also include a performance testing phase.
What is performance testing
When it comes to performance testing, it’s, in a nutshell, about standing with the user, trying to understand how and when the application is used, with the aim of preventing any potential problems. Faced with unstable connections, hardware whose technical characteristics and widely varying usage situations are difficult to quantify, even the best-written software can struggle.
Performance testing is primarily used to prevent user discomfort, situations that negatively impact the application owner or manager. Just think, for example, of an e-commerce app that can’t work with some smartphones due to configuration, connection, or the number of simultaneous logins. Or, to the smart working worker grappling with inefficient procedures in interacting with company systems. With accurate smart testing, all these drawbacks can be avoided in advance.
Performance testing, a development partner
While it’s certainly not possible to predict every possible combination of scenarios, as far as developers reach, help can come from the most current development methodologies like DevOps. In the sequence of steps, performance testing must occupy a fixed role. On the other hand, acting by modules helps identify weaknesses, while maintaining the need to always evaluate the application as a whole.
In practice, it means identifying a series of tests where certain benchmarks allow you to evaluate the health of a software, in relation to the environment in which it runs and its ability to withstand workloads without significant repercussions on performance.
On the one hand, there are therefore classic aspects such as speed, stability and reliability. On the other, the elements most related to the system with which the user interacts. For example, we are talking about servers, connecting and accessing data, with related security procedures.
The real goal is not so much to evaluate the whole under standard conditions, but instead to test the infrastructure under limit conditions, so as to evaluate behavior in peak situations and identify bottlenecks that need to be addressed.
Load and stress, the decisive tests
There are several possible activities for a performance testing strategy. However, two represent the main ones, from which to start: load testing and stress testing. Depending on the objectives, these two tests may involve a variable number of phases, while the first objectives include identifying the load capacity that the system can support, or the required one, and defining the scalability criteria needed to promptly adapt resources to user needs. In any case, these are conceptually simple procedures, with the possibility of relying on dedicated tools.
To perform the tests, KPIs must be identified, the indices from which to evaluate their performance. A delicate phase, where the Key Performance Indexes must be as stable as possible over time, so as to allow comparisons even in the long term. A safe path is to rely on the tools available on the market, which can also ensure uniformity in procedures and reliability in comparing results. When necessary, relying on consultants experienced in the field, ready to support in identifying critical points and to provide guidance resulting from broader experience. Among the most widely used KPIs, throughput, amount of memory used, average response time, interactions completed per second, response time on a single operation, and number of average accesses per second supported.
The goal is to test systems and applications under extreme conditions of use. Load testing must therefore simulate the access of a growing number of users, with related behaviors, and evaluate their performance. It must still remain a real scenario, reconstructed based on a current situation.
However, load testing can be performed from the development stages. Even in the absence of real-world situations, subjecting software to a growing and complex set of demands helps us understand to what extent performance remains satisfactory and, if necessary, identify bottlenecks that need to be addressed immediately.
In summary, it is about finding the limits beyond which individual infrastructure components struggle to deliver performance, both in individual modules and as a whole.
Stress testing, on the other hand, allows the analyses to be completed thanks to the information obtained from the previous phase. The entire system, hardware and software, is subjected to an increasing load in order to estimate the ability to adapt and react without significant impacts on user-side performance.
It is not just a question of quantifying maximum levels for resources. It is also important to evaluate the response to external events, starting with cyberattacks on IT systems, or the ability to return to standard levels once the peak has passed.
This identifies a level of criticality, beyond which the overload is such as to put the entire usability of the applications at risk. Understanding the potential danger situation early, however, will allow you to be ready. Anticipating the need to promptly adjust aspects such as hardware resources or connection effectively prevents problems from reaching the end user, benefiting the quality of the service provided, but also the company’s image.