Service level objective examples: 5 SLO examples for faster, more reliable apps

In today’s fast-paced digital landscape, ensuring high-quality software is crucial for organizations to thrive. Service level objectives (SLOs) provide a powerful framework for measuring and maintaining software performance, reliability, and user satisfaction. Certain service-level objective examples can help organizations get started on measuring and delivering metrics that matter. Teams can build on these SLO examples to improve application performance and reliability.

Measuring application performance is increasingly important because as organizations digitally transform, they’re also accelerating the speed of software delivery. According to the 2023 Dynatrace CIO Report, 78% of respondents deploy software updates every 12 hours or less. 54% deploy updates every two hours or less, and 20% deploy updates every minute or less. But the pressure on CIOs to innovate faster comes at a cost. More than half of CIOs confirmed that they often make tradeoffs among code quality, security, and reliability to meet the need for rapid software delivery.

SLOs are a valuable tool for organizations to ensure the health and performance of their applications. Serving as agreed-upon targets to meet service-level agreements (SLAs), SLOs can help organizations avoid downtime, improve software quality, and promote automation in the DevOps lifecycle. In this post, I’ll lay out five SLO examples that every DevOps and SRE team should consider.

Foundational service level objective examples for every industry

Organizations in every industry need their services and applications to perform responsively, safely, and reliably so they can meet customer expectations. To illustrate how our five SLO examples apply to different applications, we will explore the following two use cases:

• E-commerce websites: Whether you use Amazon, Walmart, BestBuy, or any other websites to buy and sell goods, we all expect a seamless shopping experience. E-commerce websites are a great way to explain how IT teams can apply SLOs to any use case or application. These organizations rely heavily on performance, availability, and user satisfaction to drive sales and retain customers.
• Fitness apps: During the pandemic, fitness apps boomed. While gyms and fitness studios have since reopened, these apps are still extremely popular for squeezing in short home workouts, tracking fitness goals, and receiving personalized training recommendations. Similarly, SLOs play a crucial role in ensuring a flawless, engaging user experiences.

The goal for DevOps and SRE teams is to collaborate around a common set of objectives to improve software quality and reliability. The ultimate result is that customers enjoy an exceptional user experience. Let’s dig into these foundational SLO examples.

Five SLO examples for faster, more reliable apps

Once you get started with these service-level objective examples, you can branch out to develop more targeted SLOs suited for your business.

1. Availability

Availability SLO quantifies the expected level of service availability over a specific time period. It represents the percentage of time a system or service is expected to be accessible and functioning correctly. Availability is typically expressed in 9’s, such as 99.9%. It helps organizations set clear expectations for uptime and establish a baseline for performance and reliability. Meeting or exceeding availability SLOs is crucial for providing uninterrupted services, minimizing downtime, and maintaining customer satisfaction.

E-commerce website: The e-commerce website should be available 99.9% or 99.99% of the time. This SLO example provides a standard of availability that allows customers to browse and purchase products without interruptions. Any scheduled maintenance or downtime should occur during off-peak hours to minimize the impact on users.

Fitness app: Likewise, the fitness app’s online class streaming feature should also deliver 99.9% or 99.99% availability. The availability SLO ensures that the online classes offered through the fitness app’s streaming service are accessible with minimal downtime. It aims to provide a reliable platform for users to participate in live or pre-recorded workout sessions, virtual training, or fitness tutorials without interruptions.

2. Response time

Response time refers to the total time it takes for a system to process a request or complete an operation. A low response time improves user engagement and encourages users to continue staying on the app/ website. For the response time SLO example, find the difference between the time the request was made and the time the response was received. This SLO is crucial for providing a frictionless, satisfying user experience.

E-commerce website: The e-commerce website should load within one second for each page request. This ensures that customers can quickly navigate through product listings, add items to their cart, and complete the checkout process without experiencing noticeable delays.

Fitness app: The fitness app should offer a response time of less than 500 milliseconds for exercise tracking and data recording. With this objective, the app ensures that users experience real-time feedback and immediate updates when logging workouts, recording sets and reps, or tracking performance metrics. This SLO enables a smooth and uninterrupted exercise-tracking experience.

Note: you might hear the term latency used instead of response time. Both latency and response time are critical to ensure reliability. Latency typically refers to the time it takes for a single request to travel from its source to its destination. Latency primarily focuses on the time spent in transit. Response time encompasses both the latency (transit time) and the time required for the system to process the request internally.

3. User satisfaction (ApDex

User satisfaction is a standard way of measuring user satisfaction with the performance of an application. It is also often measured using the Application Performance Index (ApDex). To calculate the user satisfaction service level objective example, identify the percentage of requests that meet a certain threshold for response time. For example, a user might expect a response time of one second or less. Thus, an ApDex score of 0.85 means that 85% of requests met that threshold.

E-commerce website: For an e-commerce website, maintain an ApDex score of 0.9 or above for the checkout process. This SLO example highlights the importance of a smooth and efficient checkout experience. It ensures that most users find the checkout process to be excellent or at least tolerable. It encompasses factors such as page loading speed, responsiveness, and overall ease of use during the checkout process, optimizing user satisfaction and minimizing cart abandonment.

Fitness app: For the fitness app, maintain an Apdex score of at least 0.85 for the workout video playback feature. The ApDex SLO ensures that users have a positive experience when watching workout videos within the fitness app. The Apdex score of 0.85 and above indicates that most users find the video playback performance excellent or at least acceptable.

4. Traffic

The traffic SLO example measures the amount of traffic or workload an application receives, either in terms of requests per second or data transfer rate. It ensures that the application can handle the expected workload without slowing down or crashing.

E-commerce website: The e-commerce site should support a peak transaction rate of 12,000 orders per minute during flash sales or limited-time promotions. The traffic SLO targets the website’s ability to handle a high volume of transactional activity during periods of high demand. By setting an SLO for 12,000 orders per minute, the website ensures that its checkout system, inventory management, and payment processing can handle the increased load efficiently and without significant delays or service interruptions.

Fitness app: The fitness app should support a concurrent user count of 10,000 during virtual fitness events or live-streaming sessions. The traffic SLO targets the app’s ability to handle many concurrent users during virtual fitness events, live-streaming workouts, or interactive sessions. By setting an SLO for 10,000 concurrent users, the app ensures that its infrastructure can handle the increased traffic and deliver a smooth and uninterrupted experience for users participating in virtual fitness events.

5. Success

Of all the service-level objective examples, success ties most closely to customer satisfaction. Success rate measures the percentage of successful operations or transactions that meet specific criteria. It sets targets for expected success rates in services or applications. Success rate SLOs ensure that critical operations are reliable and perform as expected. By defining success rate SLOs, organizations can monitor and improve the success rate of important processes to enhance user experience and overall service quality.

E-commerce website: For e-commerce, sites should maintain a success rate of 99.5% for product search requests. This means that 99.5% of search queries made by users should yield accurate and relevant results. By monitoring the success rate against this SLO, the website can ensure that its search functionality is performing optimally and delivering satisfactory results to users. It allows the website to identify and address any issues that may impact the accuracy and reliability of search results, enhancing the overall user experience and increasing the likelihood of successful product searches.

Fitness app: The fitness app should maintain a success rate of 98% for workout video playback. This means that 98% of video playback attempts should be successful, without buffering issues or playback errors. By monitoring the success rate, the fitness app can ensure that users can seamlessly access and view workout videos, providing a smooth and uninterrupted fitness experience.

Best practices to help ensure the performance and availability of your applications

In addition to leveraging these service level objective examples, consider the following best practices:

• Perform synthetic tests: Synthetic testing is a practice that applies automated simulations of user interactions with a website to help measure the website’s performance under controlled conditions. Such testing makes it easier to detect any potential issues before they impact real users. Synthetic tests can monitor performance and availability and can be run from multiple locations to simulate user traffic from different regions. Teams should conduct synthetic tests regularly, simulating common user actions such as browsing product categories, performing searches, and making purchases. In addition, teams can schedule these tests hourly or daily to ensure that critical transactions are functioning properly and meeting performance expectations.
• Maintain optimal resource utilization: Ensuring efficient usage of CPU, memory, storage, and network bandwidth is of utmost importance for any website or application. By closely monitoring and tracking resource utilization, organizations can right-size their infrastructure and optimize infrastructure spend to handle both off-peak and peak usage scenarios. This not only leads to cost savings but also guarantees a consistently smooth user experience.

Getting started with service-level objective examples using Dynatrace

Since applications in every industry need to meet the same fundamental goals for speed and reliability, creating the SLOs to meet those basic goals should be easy. In addition to these service-level objective examples, Dynatrace can jumpstart your SLO journey. To help you get started with SLO examples and beyond, Dynatrace provides pre-configured templates for SLOs out of the box that support the Site Reliability Engineering (SRE) fundamentals published by Google. You can also define your own SLOs to meet any specialized performance need or metric.