Can you imagine a company with no one to manage the IT infrastructure and operations? Probably not. And this is where Site Reliability Engineering and DevOps come in. Both these cultures and sets of best practices have grown in popularity in the IT world in recent years; and the trend seems far from over. However, are DevOps and Site Reliability Engineering really different or are they just different names for the same thing? This article will help you understand the differences between SRE vs DevOps.
DevOps is an approach to software development. What in particular differentiates the approach from other methodologies is that DevOps follows either lean or agile principles. DevOps focuses on enabling continuous delivery, with a frequent release rate and an automated approach to software and app development. The DevOps approach includes a set of norms and technology practices that enable the fast flow of planned work. By planned work, we mean everything from development, through testing to operations. The DevOps process has the following goals in mind:
- Accelerate the delivery of products to market.
- Shorten the software development life cycle.
- Improve responsiveness to market needs.
So, what is DevOps? DevOps is a fusion of development and operations teams, for the purpose of deploying code as smoothly and quickly as possible. It depends on establishing a cycle of close communication, combined with a high level of automation. According to the DevOps process rules, the team that is responsible for coding is also responsible for maintaining the code once in production. It means that the traditionally separate teams of development and operations collaborate to improve software releases.
Firstly, DevOps improves the speed of software delivery by making smaller changes and releasing more frequently. Thus, companies can bring products to market faster. Updates and fixes are also easier and faster, and the software‘s stability is improved. What is more, small changes are easier to roll back quickly, if necessary. Another bonus is that the team’s software delivery capability is more secure.
DevOps is a great way to build a culture of collaboration from the very beginning. The approach focuses on the team that must work together to deploy the code to production and then maintain it. It means that the DevOps team is responsible for both writing the code, fixing the bugs and anything else related to the code. The DevOps process has five key principles:
- Break down silos – the DevOps team’s role is to bring together knowledge from the development and operations sides. Thus, more insights can be gained, and communication is encouraged.
- Accept failure and fail fast – the DevOps process defines methods to mitigate risk. This way, the same mistakes are unlikely to happen twice. The team uses test automation to find the mistakes early in the release cycle.
- Introduce change gradually – the DevOps team deploys small, incremental changes regularly, instead of deploying large changes to production. This makes it easier to review changes and address bugs.
- Leverage tools and automation – the team builds the release pipeline using automation tools. This increases speed and accuracy and minimizes the risk of human error at the same time. Unnecessary manual work is reduced.
- Measure everything – DevOps uses data to measure the outcomes of any activities taken. The four most common metrics for the success of the DevOps process are: lead time for changes, deployment frequency, time to restore service, and change failure rate.
In order to function properly, DevOps needs some powerful tools for their workflows. Among others, they use version control for all code (using tools like GitHub or GitLab), continuous integration tools (Jenkins, Spinnaker, etc.), deployment automation tools, test automation tools (Selenium, etc.), and incident management tools (PagerDuty, Opsgenie, etc.)
>> Learn how CodiLime's DevOps team built CI/CD for a full-stack monitoring and alerting service.
The concept of Site Reliability Engineering was first introduced in 2003. It was originally created as a framework to support developers in the building of large-scale applications. Now, SRE is carried out by a team of experts with strong development backgrounds who apply engineering practices to solve common problems when running systems in production. It’s like a system engineer who’s also in charge of operations. It’s a combination of system operations responsibilities with software development and software engineering. A broad range of responsibilities is included – from writing and building the code, through shipping it, before ending at owning the code in production.
The main objective of Site Reliability Engineering is to develop a highly reliable and ultra-scalable system or software application. In the past, operations staff and software engineers were two groups with different types of work. They approached problems in different ways. Site Reliability Engineering goes beyond such an approach, and its collaborative nature has been gaining in popularity.
First, Site Reliability Engineering enhances uptime greatly. The approach focuses on keeping the platform or service no matter what. Tasks like disaster prevention, risk mitigation, reliability, and redundancy are of the utmost importance. The SRE team’s main goal is to find the best ways to prevent problems that can cause downtime. This is crucial especially when you manage large-scale systems. Another benefit is that Site Reliability Engineering helps brands eliminate manual work which gives developers much more time to innovate. Any flaws are found and fixed quickly and efficiently.
The role of Site Reliability Engineering in a company is quite simple – the SRE team makes sure that the platform or service is available for customers whenever they want to use it.
What are the duties of SRE?
- SRE removes silos but in a different way than DevOps. SRE helps developers create more reliable systems as they are focused on operations as well as development. Consequently, the developers have a much better context for supporting systems in production.
- SRE depends on metrics to improve the system. This perspective on reliability is a great asset when determining if a release for a change will go to production or not. At the core of SRE are three metrics: SLO (service-level objective), SLA (service-level agreement), and SLI (service-level indicator).
- Site Reliability Engineering handles support escalation issues. The system also encourages people to conduct and report on incident reviews.
- The SRE team determines and validates new features and updates, as well as develops system documentation.
A Site Reliability Engineering team uses the system used by the platform, like Kubernetes (one of the most famous container orchestrators), cloud platforms (Microsoft Azure, Amazon AWS etc.), project planning & management tools (JIRA, Pivotal Tracker) and source control (GitHub etc.).
Simply speaking, DevOps is for writing and deploying code. SRE, on the other hand, is more comprehensive, with the team taking a wider ‘end-user’s’ perspective while working on the system.
A DevOps team works on a product or app using an agile approach. They build, test, deploy and monitor applications with speed, control, and quality. An SRE team regularly provides the developers’ team with feedback. Their goal is to leverage operations data and software engineering, mostly by automating IT operations tasks - all of which will accelerate software delivery. A DevOps team’s job is to make the overall organization more efficient and automated.
SRE’s goal is to streamline IT operations using methodologies that were previously used only by software developers. Site Reliability Engineering is focused on keeping the app or platform available to customers (it includes a strong focus on the customer’s needs by prioritizing the Service-Level Agreement, Service-Level Indicator and Service-Level Objective metrics). DevOps, on the other hand, focuses on the overall processes that should result in successful deployment of a product. Below you will find more differences between DevOps and Site Reliability Engineering.
DevOps combines the skillsets of developers and IT operations engineers. SRE solves the problems of IT operations using the developer’s mindset and tools.
DevOps teams mostly work with the code. They write it, test it, and push it out into production to get software that will help someone’s problem. They also set up and run a CI/CD pipeline. Site Reliability Engineering has a somewhat broader approach. The team carries out analysis to learn why something has gone wrong. They will do anything to prevent the problem from continuing or reoccurring.
We know the differences now but are there any similarities between DevOps and Site Reliability Engineering? The truth is, SRE and DevOps have many things in common as they both are methodologies put in place to monitor production and ensure that operation management works as expected. Their common goal is a better result for complex distributed systems. Both believe that change is necessary to improve. Both focus on people working together as a team with shared responsibilities. DevOps and SRE believe that keeping everything working is everyone’s responsibility. Ownership is shared – from initial code writing to software builds to deployment to production and maintenance. Both Site Reliability Engineering and DevOps engineers write and optimize code before deployment in production.
Summing up, DevOps and SRE should work together towards the same goal.