'Improving Observability Through Service Level Metrics' observability infrastructure
If you work in infrastructure technology, chances are you spend a lot of time working with IT operations teams. You’ve watched them invest lots of hard work trying to meet the expectations of the business, but they’ve come away with limited success. The business continually bashes IT for providing poor service, while IT struggles to meet seemingly nebulous expectations with limited resources. The major problem here is the fundamental disconnect over how IT and the business each measure success.
IT is responsible for sharing limited resources between business functions, so they measure consumption. IT then uses those metrics to recognize when a resource is close to exhaustion to avoid problems and keep costs low. On the other hand, the business needs responsive and error-free services, so they measure success using speed and quality. The disconnect is two teams with drastically different definitions of success, resulting in lots of tension between IT and the business.
If you want a simpler and more responsive observability practice, tighter alignment with the business, and faster paths to improvement, you should focus on service-level metrics instead. In this article, I’ll introduce two metrics that should matter for your observability practice – service level indicators and service level objectives – and I’ll show you how to set your SLOs.An SLI is a carefully defined quantitative indicator of some aspect of the level of service that is provided.
The key here is to pick a metric for your SLI that is clearly and unambiguously related to service delivery and is simple and easy to communicate to non-technical people. That will resolve the disconnect, making things easier for everyone involved.An SLO is simply a goal that you set for your SLIs. First, you identify your SLIs. Then, by setting thresholds for each SLI, you create your SLOs.
SLOs should be easy for even non-technical stakeholders to understand. Stand-alone resource consumption metrics, such as CPU utilization, don’t tell you if something is performing well or not—they require interpretation by an SME. Identifying business-impacting SLIs, setting SLOs, and properly presenting them means that the consumers of those SLOs don’t have to ask if the number is good or bad. Interpretation is intuitive—the answer is “good” or “not good.