What Is Site Reliability Engineering and Why Do Companies Need It?
The author of this article is EPAM Senior Systems Engineer Anton Sukhanov.
Introduction
We live in a digital age, and the smooth operation of online services is essential for every organization. Downtime, performance issues, unstable software release processes, and the increasing complexity of infrastructure management — this is where site reliability engineering (SRE) comes into play. In this article, I explore the basics of SRE and its role in modern businesses.
What is site reliability engineering?
Site reliability engineering (SRE) is a discipline that originated at Google and has since been adopted by many companies. It began as a response to the growing complexity of digital systems and the need to maintain them reliably.
You may have heard of SRE when learning about DevOps, but it's important to differentiate the concepts. In general, DevOps focuses on delivering applications and services with a short and stable release lifecycle, while SRE concentrates on maintaining the software in production with a high level of availability and stability.
To better understand SRE, let's consider its basic principles:
1. Automation: SRE teams use specialized tools to manage and operate complex systems, reduce manual actions, and minimize potential human errors. Those tools include Terraform, Ansible, Grafana, and many others.
2. Service level objectives (SLOs): SRE teams define and measure SLOs, which are specific targets for the performance and reliability of a service. These objectives help teams focus on what matters most to users. For example, we can agree that a main page should open in less than 3 seconds, or that a website should be available with SLO of 99.9% (which means only 1 minute and 26 seconds of daily downtime are acceptable).
3. Error budgets: An error budget is the amount of downtime or number of errors that a service can experience without violating its SLOs. SRE and development teams use error budgets to make informed decisions about when to prioritize feature development and when to focus on system reliability.
4. Monitoring and alerting: SRE teams use modern monitoring, alerting, and observability tools to detect and respond to issues in real time. In addition, metrics forecasting and anomaly detection have become increasingly available to every SRE team. This helps minimize downtime and performance problems before they appear or become noticeable to users.
5. Incident response and postmortems: When an issue occurs, SRE teams follow a well-defined incident management process to resolve it quickly. Also, SRE teams prepare a postmortem — a special document in which the root cause of the issue is analyzed and further actions are planned to prevent such situations from occurring in the future.
6. Capacity planning: SRE teams are responsible for ensuring that systems have enough capacity to handle current and anticipated future user traffic and workload, but that the system capacity is not over-provisioned, to keep infrastructure costs as lowest as possible.
7. Change management: SRE teams introduce processes of implementing changes reliably. Practices like canary deployments and gradual software rollouts are used to minimize the risk of introducing errors in the running systems and to provide a “rollback” feature.
To learn more about SRE, I recommend reading these free SRE books.
Why is reliability so important?
Today, reliability is critical for several reasons. Users expect a flawless experience and may quickly abandon services that experience downtime or performance issues. Breaches in reliability also have significant economic consequences, especially in industries such as e-commerce, finance, and healthcare.
Even a single major outage can damage a company's reputation and undermine the trust of its customers, partners, and stakeholders. By contrast, consistent reliability makes companies stand out among their competitors and ensures that their products are always available when needed.
Adopting SRE in your company
Implementing SRE in an organization can change the way that you handle and provide digital services. It starts with an evaluation of the current infrastructure, procedures, and team abilities. This self-evaluation helps to identify the weakest areas that most urgently require improvements, and also ensures that clear objectives and performance metrics align with your company’s specific goals and customer expectations.
To achieve successful SRE adoption, it's essential to provide proper training. SRE team members must possess certain specialized skills in the areas of automation, monitoring, and incident response. Sometimes, this requires hiring experts who already have all the needed skills and knowledge and can share their expertise.
Another crucial point here: you should carefully define your service level objectives (SLOs) and error budgets, since they provide measurable performance targets and guide your reliability efforts from the very beginning.
Adopting SRE is more than just implementing tools and processes; it fosters a culture of collaboration, shared responsibility, and continuous improvement.
Conclusion
SRE is not just a set of best practices and tools. It's a mindset that drives continuous improvement, the primary objective of which is to create reliable and scalable software.
As technologies continue to evolve, I believe that SRE will continue to play an important role in keeping our digital world running smoothly, and benefitting both businesses and customers.