The growing importance of technology in business success has forced practically all companies to hire competent, experienced IT professionals. As technology ecosystems become increasingly complex, organizations need a broader range of professionals to focus on tasks like product development, troubleshooting, and customer services. SRE and DevOps have emerged as two of the most critical approaches to success. While they often take different approaches to technology, they play complementary roles that can streamline processes.
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What Is SRE (Site Reliability Engineering)?
Site reliability engineering (SRE) tends to focus on making systems as reliable as possible. In practice, SRE often looks as much like a philosophical approach to technology as it does a specific set of tasks. For example, SRE emphasizes system traits and principles such as:
- Automations that reduce or eliminate repetitive tasks.
- Designing and implementing observability to ensure system performance.
- Planning for changes in capacity.
- Establishing and measuring reliability goals (more on that below).
- Creating, testing, and fine-tuning incident management processes.
- Chaos engineering that pushes systems and products to their limits to see how they will respond to unexpected events.
- Embracing risk, which is inevitable.
- Monitoring distributed systems.
- Eliminating toil as much as possible.
Members of an SRE team can play diverse roles. However, most people working in SRE focus on key operations like:
- Making software that customer support teams can use to escalate tickets.
- Addressing escalation issues.
- Capturing and measuring data to help ensure success through planning.
- Writing post-incident reviews that document events.
SRE relies on data, so it needs well-defined indicators. Some of the most important KPIs include:
- Uptime.
- Downtime.
- Availability.
- Mean time between failures.
- Mean time to resolution.
- Mean time to respond.
What Are the Roles of SLAs, SLIs, and SLOs for SREs
SLA, SLI, and SLO play critical roles in SRE. As a quick overview:
- The SLA (Service Level Agreement) defines commitments between two parties, such as a company and its clients.
- The SLO (Service Level Objective) establishes goals for companies to meet.
- The SLI (Service Level Indicator) provides real-world metrics.
The Role of SLA
An SLA sets commitments that a company will strive to meet. For example, you might enter an agreement that requires your company to maintain 99% server uptime. This matters to SREs because it sets a baseline of expectations. Those expectations might not get met as intended, but SREs need these commitments to measure whether the company met them or how close they came to doing so.
The Role of SLO
SLOs further the goals you must meet to comply with the SLA. For example, if the SLA has a duration segment, you might see that the company needs to maintain 99% uptime. If the SLO falls short, then it doesn’t meet the SLA. SLOs, however, can give SREs deeper insights into why an SLA was or was not met.
The Role of SLI
SLIs give you real-world metrics instead of the KPIs you planned to meet. To follow the above examples, you might find that your company’s server had 98% uptime, which violated the contract. SRE would look into this issue and find ways to improve uptime to meet expectations going forward.
Benefits of SRE
SRE offers numerous direct and indirect benefits. Some of the most noteworthy direct benefits include:
- Improving accuracy by automating tasks.
- Reducing workloads through automation.
- Identifying and removing bugs early in the development process.
- Contributing to the improvement of corporate cultures.
- Freeing up time for other employees to create value.
- Modernizing systems and tools to work more efficiently and accurately.
- Comparing expectations and results to identify potential problems that need addressing.
Indirectly, SREs do a lot of work that contributes to the effectiveness of DevOps and other professionals. When IT infrastructures, applications, and features work as planned, everyone has more time to focus on meaningful work.
Site reliability engineering primarily deals with solving operational problems. Professionals have diverse skills that help them identify issues and solve them quickly. By doing their jobs, they make every aspect of a company work better.
What Is DevOps?
While SREs focus on operational development, DevOps concentrates on improving development teams and enabling fearless deployments. Teams typically use continuous iterative processes that increasingly lead to better versions of applications. A continuous iterative process takes one step toward building a product. Then, the team stops to review and test its work. They might even request feedback from other developers. DevOps team members then use what they have learned to improve the product and take another step forward. This process continues until it has a product ready to release.
The work of DevOps doesn’t end once an application gets deployed. It also requires monitoring the product, identifying bugs, and fixing bugs to improve customer experiences.
Key Operations and KPIs
Some key performance metrics DevOps teams should expect include:
- Change volume — Change volume measures how much code a team needs to change between iterations. You can capture this metric by comparing the amounts of changed and static code between versions.
- Deployment time — Once changes get approved, the DevOps team can roll them out. Deployment time measures how long it takes to implement approved changes.
- Deployment frequency — Deployment frequency describes how often a team releases updates. In most cases, organizations prefer a steady timetable such as updating applications weekly or biweekly. Unexpected events, however, can force DevOps to deploy additional changes.
- Change failure rate — You want a change failure rate as low as possible. Well-made code and a sturdy IT infrastructure can help reach that goal. Monitoring the change failure rate, however, will help DevOps identify and solve issues.
- Failed deployment rate — Deployments can cause outages and other problems. The failed deployment rate describes how often these issues occur when updating applications.
- Time to detection — Time to detection measures how long it takes DevOps to notice a problem. It should be as short as possible since long detection times tend to create bottlenecks, as tasks sit waiting in queues.
- Mean time to recovery — Unexpected problems happen. A short mean time to recovery shows that a DevOps team knows how to identify and solve problems quickly.
- SLA Compliance — SLA compliance helps ensure that companies avoid fines and enjoy positive brand reputations. A low compliance rate could quickly lead to lost clients.
- Availability — In a perfect world, DevOps could offer 100% availability. In reality, something will usually get in the way of such a lofty goal. Set a realistic availability goal, such as 99%, to manage expectations and comply with service agreements.
The specific DevOps KPIs organizations track depend on the products they make and the procedures they follow. More often than not, though, the above metrics can determine whether a DevOps team does its job well and is moving in the right direction.
CI/CD (Continuous Integration/Continuous Delivery): Explained
Also known as a CI/CD pipeline, continuous integration/continuous delivery is a coding philosophy focused on rapid, frequent code changes.
The continuous integration aspect of this philosophy has become necessary as tech ecosystems have become more diverse. Few companies want to build products for a specific operating system or device. Instead, they want to continuously alter their products so they can integrate with a broader range of devices, including those that use Android, iOS, macOS, and Windows. Since hardware and OS developers update their products frequently, it makes sense for DevOps to follow their strategy. Otherwise, products can become too outdated for contemporary users.
Continuous delivery refers to the frequent deployments that companies must rely on to update their products. DevOps takes on an agile mindset with CI/CD, which includes small loops of development and constant incremental value. Each loop has core phases (design, develop, test, deliver) but customer interactions are constant.
CI/CD should include as much automation as possible. Continuous testing can include automated tests for regression and performance. When inefficiencies or bugs occur, some updates can deploy automatically. Others require human intervention, especially when the issue’s source isn’t clear and may require a creative solution.
CI/CD works best for companies with products that they want to deliver to multiple environments and one of the main benefits is that it focuses on customer feedback and interaction to improve the applications and experience. It’s not always the most efficient solution, though, such as when a company makes an application for internal use. Since most of the people accessing the app use the same operating system, DevOps doesn’t need to worry nearly as much about performance issues between devices.
Benefits of DevOps
- Faster delivery times built on a cycle of automation, continuous delivery, and user feedback.
- More frequent updates that help ensure product stability.
- Greater collaboration between teams, which leads to deeper insights and more successful product development.
- Automated tasks give developers more time to experiment and innovate.
- Improved user and customer experiences.
- Reducing — ideally eliminating — silos between teams and departments.
- Lower management and maintenance costs.
Biggest Differences Between DevOps and SRE
Clearly, there is some overlap between DevOps and SRE. Some philosophical and practical boundaries separate the two concepts.
SRE Wants to Reduce Failures Through Understanding
As discussed above, SRE relies on SLI and SLO to measure levels of success and failure. The measurements, however, are just the beginning steps of identifying and understanding issues that prevent companies from reaching their goals. While DevOps might look for the immediate cause of disruption, SRE wants to drill deeper to understand the underlying cause of a failure. That way, it can prevent future problems and keep costs as low as possible.
SRE Tends to Collect More Data About Events
DevOps and SRE need data to reach their goals. DevOps, however, takes a pragmatic approach that often means reviewing just enough information to solve an immediate problem. From the DevOps perspective, more issues will always arise, so it makes sense to focus on today’s problem instead of thinking too much about the future.
SRE wants as much data as possible about events. Patching today’s problem is important, but the process doesn’t end there. SRE collects and analyzes more information so it can look down the line to identify future problems. Solving potential issues now creates opportunities for improved efficiency at lower costs.
SRE and DevOps Take Different Approaches to Unified Communications
DevOps sees reducing silos as the most effective way to improve communication between departments, teams, and individuals. It wants every team to align with the company’s vision, so it gives everyone access to pertinent knowledge instead of letting certain experts make decisions independently.
SRE rarely worries about how many silos a company has, although the result often reduces the number, anyway. Instead, SRE wants everyone in the organization to use the same tools and follow uniform practices. As a result, everyone gains ownership of the organization’s techniques. Shared ownership ideally leads to shared information and responsibility.
What Are the Similarities Between DevOps and SRE?
DevOps and SRE take different approaches to solving problems, but they ultimately share several goals. Some critical similarities between DevOps and SRE include a focus on:
- Using incremental change to move quickly.
- Reducing silos between teams and departments.
- Taking advantage of automation when possible.
- Monitoring network and application performance to identify problems and improve products.
Overall, DevOps and SRE want to make digital productions more effective and efficient. The key difference is that DevOps typically takes a practical approach to solving immediate problems, while SRE takes a deeper dive to explore underlying issues and how to avoid them in the future.
How SRE and DevOps Can (and Do) Work More Successfully Together
CIOs and other decision-makers should know that they don’t have to choose between SRE and DevOps. More often than not, the approaches can complement each other to find successful solutions and improve overall performance.
Overlap between SRE and DevOps teams often becomes most apparent during deployments, setting SLAs, and correcting unexpected issues.
Deployments
Deploying a new product usually represents the culmination of months spent working on minute details. No company wants to roll out a product that users find unsatisfying. DevOps and SRE work together to prevent such a calamity.
DevOps prefers rolling deployments that contribute to product reliability. Instead of throwing an entire product suite at a customer, DevOps will release new features and fix any bugs as they emerge. At the same time, SRE measures practically every event during deployment. Did users lose access? If so, for how long? Did the product slow as more users adopted it?
Collecting this information during rolling deployments feeds back into DevOps to let the team know what issues to correct.
Setting SLAs
Most people associate SLAs with SRE. While it’s true that SRE works with SLAs much more often than DevOps do, SRE often relies on information from DevOps to establish and monitor SLA performance.
When DevOps feeds information to SRE, a company can work on assuring that they have agreements they can satisfy and that they can adapt to any changes to keep meeting their obligations. You want to see a flow of information that moves between both teams.
Correcting Unexpected Issues
Eventually, every development team will encounter an unexpected issue. You never like to see them, but they create new opportunities for DevOps and SRE to find solutions. Most likely, DevOps will find a quick way to patch the problem and keep users happy. Meanwhile, SRE can take a closer look at the issue to determine its underlying cause and make plans for avoiding disruptions in the future.
The Future of DevOps and SRE
As companies rely more than ever on digital products, they will need the ongoing support of DevOps and SRE. It seems likely that the two teams will remain separate. However, you can expect to see more collaboration and reliance between DevOps and SRE. Recognizing that they share some overlap only makes their efforts more fruitful. Keeping them separate, however, serves companies by providing different perspectives that lead to more efficient solutions.
