What are service-level objectives (SLOs)?

Service-level objectives (SLOs) are important pieces that are used to define service-level agreements (SLAs). As described by Wikipedia, “SLOs are specific, measurable characteristics of the SLA, such as availability, throughput, frequency, response time or quality. These SLOs together are meant to define the expected service between the provider and the customer and vary depending on the service’s urgency, resources and budget.”

Google breaks down the components of SLAs and SLOs further in the Site Reliability Workbook. Understanding the terminology and how each part fits together is a vital component in creating an SLO methodology that works for your business.

Service-level terminology

• Indicators: A service-level indicator (SLI) is the defined quantitative measure of one characteristic of the level of service that’s provided to a customer. Common examples of such indicators are error rate or response latency of a service.
• Objectives: A service-level objective (SLO) defines the target value for the service level that’s measured by a service-level indicator. As an example, the SLO could specify that a given SLI is 99.9% of the time fulfilled.
• Error budget: The specified target value of an SLO implicitly defines a small budget where the service is allowed to not work fully reliably. This error budget allows for the planned or unplanned downtime of the service that’s unavoidable in practice.

Why implement SLO methodology?

IBM has done extensive research on SLO methodology among our client base to better understand how it’s being used in practice. We have learned that SLOs, as a methodology, are gaining a lot of adherence. As such, many organizations are looking for tools and advice on how to best implement their SLO methodology.

When done properly, SLOs promise to enable teams to improve decision-making and prioritization around reliability and feature development. Having an SLO methodology in place improves communication across the board by making those conversations more factual and less emotional when it comes to the impact of incidents. And they even help make better business decisions based on current SLIs. Last, but not least, they help improve overall organizational monitoring maturity.

Managing SLOs and SLIs in the IBM Instana platform

Modeling user journeys

A common pitfall in defining SLOs is defining them as too granular instead of simplifying them by customer experience. When SLOs are too granular or in-depth, they often fail to fulfill the promises and benefits of SLO methodology, as outlined earlier. The IBM Instana solution, through the use of the Application Perspectives creation wizard, allows for SLOs to be defined by customer experience through the use of user journeys. The Application Perspectives creation wizard enables the creation of specified user journeys with easy selection and specifications through “blueprints.” With the creation wizard, the user journey specification is interactive; as items are specified the user can see what data is expected to be returned.

Configuration of SLIs

Once the critical user journeys have been identified, they need to be ordered by business impact and service owners need to determine the metrics to use as key indicators. The IBM Instana platform makes it easy to define, validate and visualize meaningful SLIs and SLOs, derive error budgets, and enable immediate root cause analysis of service level violations.

Setting up SLOs

With SLIs created based on user journeys, the creation of SLOs is simply a matter of pulling the right SLIs into the SLO you’re creating. The IBM Instana platform utilizes our custom dashboarding capabilities to create widgets for your SLOs. The SLO widget can show information for either time-based or event-based SLI configurations.

The platform’s implementation of SLI, Error Budget and SLO has been designed to be compliant with the Google Site Reliability Workbook definition of SLO methodology, as it’s currently a widely acknowledged best practice. These best practices are then enhanced by combining the SLO and SLI capabilities with Application Perspectives user journeys and tightly integrating SLI, SLO and Error Budgets with custom dashboards. This method allows for easier sharing and closer collaboration with nonengineering roles, such as product managers and business stakeholders. This process is key to fully realizing the benefits for a successful SLO methodology implementation.

The IBM Instana SLI and SLO methodology is also tightly integrated with Unbounded analytics, making it easy to quickly uncover the root cause of any availability or performance issue that leads to the depletion of error budgets or violations of SLOs.

Get started with SLOs in the IBM Instana platform today

If you want to experience the full power of the IBM Instana SLO methodology, you can sign up for a free trial and see for yourself.