What is SRE: Site Reliability Engineering 101?

In order to better understand site reliability engineering (SRE), there is a particular scenario that needs to be taken into account. Suppose there is an app that is developed to serve the financial conglomerates, such as the stock market, banks and other financial entities that come around transactions taking place on a day-to-day basis. The app is developed by the best developers and engineers under the umbrella of DevOps and using an Agile toolset; this ensures a stable and convenient build that provides efficiency and 24/7 workability. Connect with our experts to learn more about our DevOps courses.

The app is now ready and has been deployed to serve these financial conglomerates, transactions of large size are taking place every single day, and the app is working fine. The financial and personal data of the app remains secure and intact through the whole time it remained live, and everything seemed to be working at its full potential—until it didn't. The app itself continued to work properly without showing any downtime whatsoever, and then it collapsed out of the blue, and those big heavy financial conglomerates were those who suffered all the loss. Their session was interrupted heavily, and all business came to a standstill.

The backend story here to follow is that the workflow exchange for the app reached its maximum transaction threshold limit. And to further the event, there was no practical remedial plan to counterfeit the whole thing. The whole infrastructure for the app came crashing down like a pile of cards. Despite the fact that the whole thing was developed using the best DevOps practices, it could only take care of the development and deployment-related elements. The IT part of the app was left with no contingency plan to take care of the architecture if it falls prey to the immense load or if the threshold limits are reached. IT operations were not covered, not even by the DevOps systems, and it caused some serious trouble.

Origin of Site Reliability Engineering: Dissecting DevOps from RunOps

Back when the IT industry was booming, and everyone was doing extremely great, automation was not taken into account and was not also presented as a separate trait or definition that could take the world of IT by storm in the upcoming years. The point is that no one had even the slightest idea what it was until it got introduced by the end of 2010. Up till then, all the testing of the code, apps, coding/programming and implementation of the code used to happen manually.

This is where the concept of DevOps also started to flourish and take speed. Dev refers to the development side of things and Ops is all about the operations. To ensure that both of these are working side by side, cutting down costs and silos is what DevOps is all about. The functionality of DevOps lies in the fact that it is backed by the most agile building and testing environment present out there. All that the production team had to do when DevOps took charge was to maintain the runtime environment.

Then again, the lack of a proper skill set to manage IT operations is what put the whole thing into the debacle as introduced in the above depiction of app development and its efficiency in the real world when the threshold limit has been reached. This is where both the DevOps and RunOps found their differentiation and were decoupled and SRE or site reliability engineering took the post.

What Is SRE?

Site reliability engineering (SRE) is the practice and an IT shift towards the development of efficient and top-notch IT operations that support superior work efficiency, provide stability and imminent scalability according to the requirements of the production environment.

SRE's Functional Back: Software-First Approach

SRE is like asking a software engineer who knows and understands the IT assembly, operations and development how to choose their dedicated operations team. SRE functionality that builds unbeatable and highly-scalable IT operations are run by IT operational specialists who know how to code and integrate various sections of it to the application’s mainframe to avoid errors and interruptions in functionality.

The software first approach is what gets implemented by the IT operations team that can automate IT operations and take care of the failures in code execution and whatnot as soon as these arise. A continuous environment is built by these professionals where insights are drawn and provided to both the dev and ops part of the DevOps teams using a single platform. This way even the execution of the test codes can be done across the continuous environment.

Some of the skills that these professionals carry with them include: DNS configuration, remediating server systems, networking, solving the infrastructure related problems and taking care of the random glitches that persist with the applications under development or being sued by clients out there.

Resiliency is being built in every aspect of the IT operations while it also gets codified so that both the operations and the infrastructure itself can get its hands on the said resiliency against glitches, errors and other such elements. The changes can be managed then with the help of the version control tools while also getting checked for the test framework and other susceptible issues.

Error Budget Principle

Whenever a few changes are made to the infrastructure or any other aspect of the application the SRE engineers would verify the code quality of these changes and ask the development team to produce viable evidence regarding the automated test results. Service level objectives can be fixed by the SRE managers to customize the performance of the whole application in effect with the recent changes that have been made. Thus, a threshold for the permissible and minimum application downtime also gets set that is known as the error budget.

Even if downtime has to occur, it should occur with the error budget or in accordance with the maximum value appointed to it. A downtime will only get approved by the SRE managers if it is within the scale of the error budget. On the other hand, if the downtime that the developers have to suffer in correspondence with the latest changes they have worked on exceeds the principle value set within the error budget, then these changes are not taken live and are rolled back immediately for further improvements.

The ultimate goal here is to account for the performance and downtime of the changes to fall within the formula for the error budget. Anything that is beyond the maximum value for this formula gets subjected to immediate roll back and is provided to the development team so further improvements can be made to make the value falls in between the formula.

Thus, the main task that is associated with the development and initiation of an error budget is to make sure that risks can be mitigated and an overall balance between the SRE and the application development can be brought forward. The error budget remains unaffected until the availability of the system falls within the service level objectives. The adjustment of the error budget can be made by managing the service level objectives or enhancing the overall IT operability. So, at the end of the day, the ultimate goal is always related to the application's reliability and scalability.

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The Ultimate Cultural Shift: Next Step Towards Reliability and Scalability

There are various well-renowned models of the SRE systems known as the Kitchen sink or Everything SRE that you will be able to find on the market. This program only tags the SRE engineers with the developers that are random and might not be chosen by the engineers themselves to make a perfect team tread further. With the help of this model, only a Silo SRE environment could be made.

The only problem with the Silo environment is that it promotes a hands-off approach; there is a lack of coordination and proper standardization that exists due to this model. A sensible approach to work here is shelving-off a project-oriented mindset that allows the SRE tools and practices to pick up the pace and grow at a steady pace rather organically than coming out as a forced transition.

It starts with filling the teams with the customer principles and activating a data-driven method to ensure the reliability and scalability of the apps that have already been developed and shipped but also for those who are still under development. A change agent must be identified and appointed by the organization to promote a culture of maximum system availability. Observability is something that can take care of this dedicated problem and thus requires the engineering teams to be aware of the common and complex problems that are hindering the attendance of the reliability and scalability within the application.

DevOps vs SRE: Common and Advanced Differences

1. Monitoring vs Remediation

DevOps can only deal with the pre-failure situation and ensures that the conditions do not lead to a pure system crash or failure of any kind. On the other hand, SRE deals with the Post-failure conditions, and it must have a post mortem for the root cause analysis. The main goal of the SRE is to take out any potential problems that might lead to imminent failure and, at the same time, increase reliability and uptime.

2. Role Within the Software Development Life Cycle

The primary concern of DevOps is to deal with the efficient development and fast delivery of software-based products. There must not be any downtime within the development phase, and it also does require finding out the blind spots that exist within the infrastructure and the application. SRE, on the other hand, starts managing the IT operations once the application has been deployed. The main goals of the SRE are to ensure maximum application uptime and stability within the production environment.

3. Speed and Cost of the Incremental Change

DevOps at its core is all about continuous development, deployment, and ensuring the fastest possible release of software systems and tools in a dedicated fashion. While on the other hand, SRE is about making sure that the resilience and some degree of robustness remain within the new updates and features that are being rolled out gradually. But it does require some small changes that need to be rolled out at different intervals. Even if a possible failure is on the way, this strategy provides enough time to measure these changes and thus adopting the corrective measures. The cost of failure is to be brought down at all costs through efficient testing and remediation of the vulnerabilities or other given errors before time.

4. Key Measurements

The measurement plan that decides whether the whole endeavor has been a success or not revolves around CI/CD that is a continuous integration and continuous deployment. A quality feedback loop needs to be maintained by measuring the process improvements and workflow productivity. However, in the case of the SRE systems, there are a few strict regulations that need to be followed and uplifted at all possible costs. SRE does regulate the IT operations with some specific parameters, such as service-level indicators and service level objectives. For SRE, the success is counted or achieved when the application after deployment is working fine, showing no errors or security flaws whatsoever, and the efficiency, as well as the productive integrity of the application itself, remains intact.

In all the different comparisons made above the one thing that is crystal clear is that DevOps deals with the preproduction elements of the app development while the SRE deals with the postproduction elements of the same app when it has been deployed.

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