The pace of technological evolution and digital transformation has accelerated phenomenally prompting shifts in IT operations. The cloud, for example, is now almost a default technology for running software. IT infrastructures are evolving and becoming more complex. IT operations, as such, are becoming more complicated as it has to shoulder heavier lifting today than ever before.
Enterprises have to ensure the high availability and performance of their IT assets, especially as the world of work becomes increasingly hybrid. With disparate teams and global operations, managing application performance and stability becomes crucial especially when addressing changing business needs.
Site Reliability Engineering, as such, has emerged as a valuable practice when creating scalable and highly reliable software systems in this software-defined and driven world.
What is Site Reliability Engineering (SRE)?
Site Reliability Engineering or SRE takes the tasks that were traditionally conducted manually by operations teams and introduces automation and software tools to solve problems and manage production systems.
Site Reliability Engineering
- Improves the reliability of software systems.
- Manages large systems through code.
- Ensures that applications remain consistent amidst frequent updates from development teams.
- Focuses on improving software system reliability across key categories including availability, performance, latency, efficiency, capacity, and incident response.
Why do we need Site Reliability Engineering (SRE)?
The concept of Site Reliability Engineering can be credited to Google’s Ben Treynor Sloss. He famously said, “SRE is what happens when you ask a software engineer to design an operations team.” Treynor used software engineers with software development backgrounds to do the work done by the operations team and discover tasks and workloads that could move from manual mode to automation.
The key reasons why SRE is important are:
- Greater observability into service health: SRE allows engineers to track metrics, logs, and traces across different services and provides a holistic picture of system health. This provides the context in the case of an incident.
- Act as the bridge between development and operations: Site reliability engineers identify ways to improve communication and automation and fit in the gap between developers and system admins. SRE teams include developers with different specialties and focus on improving stability rather than agility and driving proactive engineering rather than reactive development.
- Improve Network Operations Center (NOC): SRE teams manage metrics and monitoring, change management, capacity planning, and emergency response. They employ automation and help operations move toward a modern NOC where issues are directed automatically to the right resource for prompt issue redressal.
- Ensure sustainability and scalability: SRE is especially beneficial when building scalable and highly reliable software systems. It administers these huge systems using code which is a more scalable and sustainable option for system administrators managing a large number of machines.
- Elevated operations planning: SRE accepts that all software, realistically, stands a chance to fail. These teams, as such, estimate the cost of downtime, understand the impact of downtime on the business, and create the right incident response plans to ensure minimal downtime for the business and end users.
- Better customer experience: The objective of SRE is to ensure that the errors in software do not impact customer experience. By creating the right processes, automation, and software tools, SRE ensures fewer errors. Greater collaboration between development and operations teams gives development teams more time to prioritize new feature development rather than remain invested in bug fixes.
Principles of Site Reliability Engineering
Since Site Reliability Engineering understands that 100% reliability is unrealistic, failure is expected and is planned for. They determine that errors are a part of the software deployment process. Instead of trying to look for a perfect solution, these teams monitor software performance.
They do so by using service-level agreements (SLAs) which clearly outline the required reliability of the system through service-level indicators (SLI) and service-level objectives (SLO). Site Reliability Engineers observe, examine, and monitor performance metrics after deploying the application in production environments.
Site reliability engineers divide time between operations tasks and project work. They spend 50% of their time on operations and the rest on tasks like new feature development, implementing automation, and system scaling. Services that perform poorly consistently are redirected to the development team thereby ensuring a balance between operations and development work.
Site Reliability Engineering is responsible for evaluating how code is deployed, configured, and monitored. They also have to ensure the availability, latency, change management, emergency response, and capacity management of services in production.
The practice of Site Reliability Engineering focuses on frequent, but small, changes to maintain system reliability. SRE provides feedback loops to measure system performance, increases the speed and efficiency of change implementation, and reduces the risks owing to changes using automation tools and repeatable processes.
‘Toil’ is any operational activity that is manual, repetitive, automatable, tactical, and devoid of enduring value. This activity also scales linearly as a service grows when running a production service. Non-urgent service-related messages and emails, releases, pushes, etc. fall under this category.
SRE reduces the toil and engineers the services to scale easily through automated software and solutions.
SRE and DevOps – are they the same?
Site reliability engineers are part of a software team and manage some operational aspects. SRE also leans heavily towards automation to accelerate development and faster remediation of issues. In this way, it seems quite similar to DevOps where development and operations teams work collaboratively, and automation is employed extensively.
Both SRE and DevOps are about team culture and relationships and attempt to bridge the gap between development and operations. However, SRE can be considered a practical implementation of DevOps and differs from DevOps as it uses Site reliability Engineers within the development team. These engineers have an operations background and know how to remove communication and workflow problems.
The other point of difference is that while SRE concentrates on balancing site reliability with creating new features, DevOps is all about moving efficiently across the development pipeline.
In the simplest of terms, Site Reliability Engineering is all about maintaining the health of the services that ensure ultra-scalable and highly reliable software systems. This approach keeps agility and stability in balance in the system, supports agile operations and development, and increases confidence in the system.