What is site reliability engineering (SRE)? Site reliability engineering (SRE) applies software engineering principles to IT operations. By automating certain tasks, SRE enhances the reliability and scalability of software systems, ensuring that applications remain viable even when experiencing frequent updates.  Demo ITOM
Things to know about SRE
What is the origin of site reliability engineering? What does a site reliability engineer do? What is an SRE team? Where does SRE fit on your team? Why is site reliability engineering important? How does site reliability engineering work? What are key metrics for site reliability engineers? What are the pros and cons of being a SRE? What is DevOps vs. SRE? What technologies and tools support SRE? How should SRE be integrated into an organization? Is ServiceNow right for SREs?

The increasing complexity of modern software systems has put immense pressure on IT operations teams. As businesses strive to innovate and push out updates at breakneck speeds, maintaining system reliability and scalability has become a formidable challenge. This rapid development pace, while essential for innovation, often leads to increased complexity and potential for system failures. Traditional IT operations teams struggle to keep up, relying heavily on manual processes that can be error-prone and inefficient. This environment has paved the way for a transformative approach known as site reliability engineering (SRE).

Site reliability engineering bridges the gap between development and operations by applying software engineering principles to IT infrastructure and operations. Today’s IT teams are increasingly adopting SRE methodologies, taking operations practices and turning them over to software engineers for automation, problem solving, and systems management. SRE teams typically take responsibility for change management, emergency response, monitoring, availability, performance, latency, efficiency, and capacity planning. By leveraging code to manage and optimize infrastructure, SRE enables organizations to maintain high availability and reliability—both of which are crucial for customer satisfaction and business success. 

Expand All Collapse All What is the origin of site reliability engineering?
Ben Treynor Sloss of Google is the mastermind behind SRE, and aptly describes it as “what happens when a software engineer is tasked with what used to be called operations.” The concept arose after an examination of the conflicts between operations, who want to ensure that features do not break anything or inconvenience end users, and dev teams, who have developed and want to release new features as soon as they are ready for a rollout. SRE is a reconciliation between the two.

Key principles in site reliability engineering 

Google published a book on SRE that is available for free online. It offers a deep dive into the role of SRE and recommended best practices for execution. Parts II and III, principles and practices (respectively) are of note:

The core principles of SRE, according to Google, are: 

  • Embracing risk  
    Provide neutral approaches to service management using error budgets.  
  •  Service level objectives 
    Provide recommendations for disentangling indicators from agreements and examines how SRE uses the terms.  
  • Eliminating toil 
    Step away from mundane and repetitive tasks that are devoid of value.  
  • Monitoring distributed systems
    Always avoid being blind to what is going on in the organization for the sake of reliability.
  • Release engineering 
    Carefully account for releases to ensure that they are consistent and do not contribute to outages.
  • Simplicity 
    Avoid complexity wherever possible; a system that is too complicated can lower reliability and become difficult to scale back to a simpler place. 

Hierarchy of a reliable service 

SREs run related systems for external or internal users, and are responsible for the services. Successful operation of the services include capacity planning, addressing root causes of outages, and developing monitoring systems. Google’s hierarchy of a reliable service are: 

  • Product 
    The top of the reliability hierarchy, which indicates that a product is workable and reliable.  
  • Development
    Software engineering and system design work within the company.  
  • Capacity planning
    Loan balancing ensures that the capacity that was built is being used properly.  
  • Testing + release procedures
    After forming an understanding of what went wrong, actively preventing it. Carefully testing products before they are released. 
  • Postmortem/root cause analysis
    Build a culture of blamelessness and addressing a fix to an issue to avoid a repeat incident. 
  • Incident response
    Being on-call, staying in touch with systems, effective troubleshooting, and careful planning before the fact. 
  • Monitoring
    Being aware of problems before the end user notices.  

SRE is a philosophy

A site reliability engineer needs the right mindset for this position. Technical skills are necessary, but a conceptual understanding of operations is key. It is important for SREs to be grounded in traditional software development processes, but there is also a great deal of importance in a holistic understanding of company processes and moving a reliable system forward. 

SRE should be a catalyst for change

Site reliability engineering should act as a driving force for change within an organization, promoting a culture of reliability across all teams. That said, this should not be the sole responsibility of the SRE team; instead, it should be integrated into the mindset and practices of every employee. By applying SRE principles across the organization, each team can contribute to creating a more comprehensive and dependable system.  

To achieve this, organizations should implement a reliability model tailored to each team's specific needs and functions. This will likely involve hosting regular discussions and workshops to explore how reliability practices can be incorporated into daily operations—and how they impact overall performance. Encouraging collaboration between development, operations, and other departments ensures that reliability becomes a shared goal, fostering an active approach to identifying and mitigating potential issues. 

What does a site reliability engineer do?
As previously stated, the SRE brings together development and operations, implementing and maintaining the infrastructure that supports high availability and performance. To do this, they depend on a range of skills and hard-earned knowledge.

SRE excellence requires experience

The role of a site reliability engineer is best performed by someone with significant software experience. It is not typically an entry-level position, as the demands of SRE require a deep understanding of both software engineering principles and operational challenges. An effective SRE must be proficient in coding, automation, and systems architecture, as well as have a solid grasp of networking, security, and database management. This combination of skills allows SREs to design and implement solutions that enhance system reliability and performance while minimizing manual intervention. 

Proper SRE execution requires not only technical fluency but also the ability to comprehend and manage systems of great scale and complexity. Experienced SREs are adept at identifying potential failure points, optimizing resource allocation, and developing strategies for incident response and disaster recovery. Their expertise enables them to create effective monitoring and alerting systems, ensuring that issues are detected and addressed promptly. By leveraging their extensive knowledge and skills, seasoned SREs play a crucial role in maintaining the stability and scalability of an organization's IT infrastructure, contributing to the overall success of the business. 

SREs play a pivotal role in creating SLAs

New launches are greenlighted based on current product performance: Applications are generally not up 100% of the time. The SRE team is often tasked with crafting a service-level agreement (SLA) to define the system, and how it will be used for end-users. A common part of an SLAent is an error budget, which specifies the maximum threshold for outages and errors. 

SREs must know how to code

Development teams and SREs share staff, meaning that an additional SRE means one less developer (and vice versa). The system is self-regulating to avoid any battles between developers and SREs for staffing needs. SREs can also code and develop, which helps them work well with the development team. 

SREs are allowed to move between projects, as SRE creates a strong sense of motivation and dedication to allow team members to pursue personal goals and objectives. 

Common roles and responsibilities for a site reliability engineer

Site reliability engineers are involved in an array of tasks designed to ensure the stability and efficiency of software systems. These responsibilities span from developing tools that support operational teams to managing critical incident responses. Here are some of the key roles and responsibilities commonly associated with SREs:

  • Building software to help operations and teams  
  • Fixing escalation issues  
  • Optimizing on-call processes  
  • Documenting team knowledge  
  • Conducting post-incident reviews
What is an SRE team?
SRE teams consist of multiple site reliability engineers working towards common goals. These teams can be structured in various ways to best meet the organization's needs. Two of the most common SRE team structures are: 
 
  • Dedicated teams 
    In this model, SREs develop service-level objectives (SLOs), runbooks, and templates that are used by multiple teams. These tools and resources are designed to be adaptable, allowing different teams to customize them according to their unique requirements.
  • Embedded SREs 
    Here, a small team of SREs or a single SRE works closely with a specific team, ensuring the reliability of their service area. This model allows SREs to address the particular needs of their assigned team, providing targeted support and fostering a deeper understanding of the team's challenges and goals. Both models aim to enhance overall system reliability by integrating SRE principles and practices throughout the organization.
Where does SRE fit on your team?
SREs can fit right at the crux of IT operations, software engineering, and support. Employed correctly, these professionals can provide a strong foundation and relationship among the teams, which helps with feedback loops, collaboration, and reliability. Additionally, SREs can be foundational in driving a culture of reliability within the organization. They bring a unique perspective that combines deep technical knowledge with a focus on operational excellence, and they can share that perspective across the company. 
Why is site reliability engineering important?

Having dedicated, capable SREs within an organization brings substantial value by enhancing system reliability, fostering collaboration, and improving overall efficiency. SREs are instrumental in maintaining the stability and quality of services, ensuring that applications perform optimally even as they evolve over time. Some of the most important benefits of implementing SRE practices include: 

  • Improved collaboration  
    SRE practices enhance collaboration between development and operations teams. By closely monitoring updates and changes, SREs ensure that new features and bug fixes do not compromise system stability. This alignment between teams leads to smoother, more reliable software releases.  
     

  • Increased automation  
    SREs identify and automate time-consuming tasks, eliminating inefficiencies and reducing manual work. This focus on automation not only speeds up processes but also minimizes human error, leading to more reliable and scalable systems.  
     

  • Enhanced customer experience 
    By using SRE tools and practices, organizations can reduce software errors that impact customer experience. Automation of the software development lifecycle allows teams to prioritize new feature development over constant bug fixes, ensuring a smoother and more satisfying user experience. 
     

  • Better operations planning  
    SRE teams understand that software can fail, so they plan for appropriate incident responses to reduce the negative impact of downtime on business operations and end users. This preemptive approach helps in accurately estimating downtime costs and mitigating its effects on the organization.  
     

  • Broad applicability  
    SRE practices are not limited to tech companies. Industries such as ecommerce, customer service, and manufacturing can also benefit from adopting an SRE culture. By implementing these principles, organizations across various sectors can achieve higher reliability and efficiency in their operations.  

How does site reliability engineering work?

Although different organizations may approach site reliability engineering differently, the SRE process typically follows a similar process: 

  1. The SRE team establishes key metrics for monitoring system performance, such as uptime, response time, and error rates.  

  2. Based on the system's risk tolerance, the SRE team defines an error budget that sets the acceptable threshold for errors.

  3. SREs utilize monitoring services to track performance metrics and detect any unusual application behavior.  

  4. When performance metrics indicate anomalous behavior, SREs identify potential issues affecting system reliability.  

  5. The SRE team compiles detailed reports of the detected issues and submits them to the software engineering team.  

  6. The software engineering team prioritizes and fixes the reported problems to maintain system reliability. 

  7. If the number of errors is within the error budget, the development team can release new features. If errors exceed the budget, new changes are put on hold until existing issues are resolved.  

  8. Developers release the updated application after addressing the identified issues, ensuring continuous improvement and maintaining system reliability. 
What are key metrics for site reliability engineers?

Metrics are essential in site reliability engineering as they help measure, monitor, and maintain the reliability and performance of systems. Here are some key metrics that SREs typically focus on:

  • Service level indicators (SLIs) 
    SLIs are specific, quantitative measures of aspects like latency, availability, and error rates. They provide insight into how well a service is performing from the user's perspective.
  • Service level objectives  
    SLOs are the target values or ranges for SLIs, defining the desired level of service reliability. They set clear expectations for performance and help prioritize improvements.  
  • Service level agreements 
    SLAs are formal agreements between service providers and customers that define the expected service levels. They often include penalties for not meeting the specified SLOs, ensuring accountability. 
  • Error budget  
    Also called an ‘error rate,’ an error budget quantifies the permissible amount of downtime or errors within a certain period. It balances the need for innovation and reliability by allowing teams to understand the trade-offs between releasing new features and maintaining system stability. 
What are the pros and cons of being a site reliability engineer?
Site reliability engineering is typically viewed as a rewarding career capable of significantly enhancing the lives of customers and team members by ensuring high system reliability and performance. While SREs are often among the happiest employees in development and IT due to the diverse opportunities and challenges they face, the role also comes with its own set of difficulties. Here are some of the key pros and cons of being a site reliability engineer: 

Pros of being an SRE

  • Opportunities for advancement
    SREs have numerous career growth paths, including specializations in cloud computing, cybersecurity, automation, and infrastructure as code (IaC). 
  • Skill development 
    The role offers continuous learning and development with exposure to new innovations, giving SREs clear opportunities for enhancing technical skills in coding, programming languages, automation tools, and more.
  • Competitive salary 
    SREs generally enjoy an above-average median salary, along with growth opportunities, work flexibility, and strong benefits (like healthcare, retirement plans, and stock options/equity). 
  • Impactful work 
    SREs play a crucial role in improving system reliability, which directly benefits customers and enhances team efficiency and satisfaction.  

Cons of being an SRE

  • On-call duties
    SREs, especially juniors, are often required to be on-call. This means being ready to work during evenings, weekends, holidays, lor any other time when the organization may require the SRE’s expertise. This can lead to potential challenges related to work-life balance.
  • Continuous learning pressure 
    The fast-paced tech landscape demands that SREs stay up to date with new tools, coding languages, and system designs, which can be stressful and time-consuming.  
What is DevOps vs. SRE?
DevOps and SRE are two approaches aimed at improving the development, delivery, and maintenance of software systems. While both share similarities in fostering collaboration and enhancing system reliability, they differ in their focus and execution: 

DevOps

DevOps is a methodology that integrates software development and IT operations with the goal of enhancing collaboration, increasing deployment speed, and ensuring continuous delivery of high-quality software. It emphasizes a cultural shift where development (Dev) and operations (Ops) teams work closely together throughout the software lifecycle. This approach exists to break down silos, improve communication, and foster a collaborative environment where both teams share responsibilities for the performance and reliability of the software.

SRE

Site reliability engineering is a discipline that applies software engineering principles to IT operations. While DevOps focuses on merging the roles and responsibilities of development and operations teams, SRE is more development-centric, originating from the need to manage complex, scalable systems effectively. Although SRE is aligned with DevOps principles, it specifically emphasizes using software engineering techniques to manage infrastructure and operations. SREs often build tools and automation to reduce manual intervention, handle incidents, and improve system reliability.  Simply put, SRE can be seen as a practical implementation of DevOps, applying engineering and automation to achieve operational excellence.

Deliver modern operations for DevOps and SRE teams

What technologies and tools support SRE?

Effectively managing and optimizing system reliability takes support and resources—typically in the form of advanced technologies. The right tools and applications help simplify otherwise-difficult tasks and give SREs the power to easily incorporate automation and data analysis into their work. The following are among the most important technologies and tools used in SRE: 

  • Monitoring tools  
    These tools continuously track system performance, detect anomalies, and send alerts. Effective monitoring helps identify and resolve issues before they impact users. 

  • Incident management tools  
    Used to streamline the incident response process, incident management tools help track incidents, facilitate communication, and ensure a timely resolution. 

  • Configuration management tools  
    These automate the process of configuring and maintaining systems, ensuring consistency and efficiency in software updates and deployments. 

  • Automation tools
    Automation is fundamental to SRE, helping eliminate repetitive tasks, reduce human error, and improve overall efficiency. 

  • Performance measurement tools  
    These tools collect and analyze performance data, helping SREs understand system behavior and identify areas for optimization. 

  • Continuous integration and continuous delivery (CI/CD) tools  
    CI/CD is used to automate the building, testing, and deployment of code, ensuring that new features and updates are delivered reliably and quickly. 

  • Linux containers 
    Containers can provide the needed technology for a cloud-native development—the containers support environment unification for integration, automation, development, and delivery.

  • Kubernetes  
    Kubernetes are used to orchestrate containerized applications, automating deployment, scaling, and operations of application containers. This technology integrates well with Linux containers.
How should SRE be integrated into an organization?

Integrating site reliability engineering into your organization will likely require careful planning and a significant cultural shift towards prioritizing reliability and collaboration. That said, there’s no reason these changes should present any major problems.   

 

Begin by educating your teams about SRE principles and benefits, ensuring buy-in from all stakeholders. This is an essential step towards fostering a mindset of shared responsibility for reliability across development and operations teams. 

 

Organizations should focus on setting clear reliability goals through SLOs and error budgets, which help guide the prioritization of tasks and resources. Additionally, by implementing automated monitoring, incident management, and post-incident review processes, teams can proactively address issues and continuously improve system performance.  

 

Through it all, regular training and open communication about SRE practices will further embed the SRE culture, keeping team members committed to the principles and goals of site reliability engineering.

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Is ServiceNow right for SREs?

SRE combines software engineering and IT operations, but why stop there? Integrating ServiceNow into your SRE practices can significantly enhance your organization's ability to maintain system reliability and performance.  

 

Available with IT Operations Management (ITOM) and built on the AI-enhanced Now Platform®, ServiceNow Site Reliability Operations offers comprehensive applications and comprehensive support for monitoring, incident management, and automation—all essential capabilities for any SRE team. ServiceNow solutions also go further, providing real-time visibility into system health, streamlining incident response, and automating routine tasks and complex digital workflows, allowing SREs to focus on strategic improvements.

 

For organizations seeking to enhance their SRE capabilities, ServiceNow provides a unified platform that supports scalability and resilience. Experience the benefits firsthand; demo ITOM today! 

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