{"head":{"title":"What Is an SLA (Service Level Agreement)? | OceanLab","description":"An SLA is a contract that promises a level of service, such as uptime or response time, and says what happens if it is missed. Example and common mistakes.","canonical":"https://oceanlab.in/glossary/sla"},"crumbs":[{"name":"Home","path":"/"},{"name":"Glossary","path":"/glossary"},{"name":"SLA","path":"/glossary/sla"}],"slug":"sla","term":"SLA (service level agreement)","aka":["service level agreement"],"category":"Reliability","short":"A contract that promises a level of service, such as uptime or support response time, and says what happens if it is missed.","body":[["An SLA turns reliability into a promise. A typical one covers ",{"href":"/glossary/uptime","text":"uptime"}," (for example 99.9% a month), support response times by severity, how outages are measured, what is excluded, and the remedy, usually service credits."],["Google's SRE book draws the line clearly: an ",{"href":"/glossary/slo","text":"SLO"}," is an internal target, and an SLA is the agreement that says what happens when targets are missed. If there is no consequence, it is an SLO, not an SLA."]],"why":["An SLA tells a buyer what they can rely on and what they get if it fails. For a supplier, it sets the bar the system and the support team must be built to meet. Promising more than the architecture can deliver is expensive."],"example":["A software vendor offers 99.9% monthly uptime, a one-hour response for critical issues, and a 10% credit for any month below target. Its internal SLO is 99.95%, so it notices and fixes problems before the SLA is at risk."],"inBuild":["When a build includes ongoing support, the SLA terms should match the hosting, monitoring and on-call setup that was actually built. OceanLab publishes a 99.9% uptime figure on its homepage."],"mistakes":[["Setting the SLA equal to the internal target, which leaves no safety margin."],["Vague measurement: whose monitoring counts, and is slow the same as down?"],["Excluding so much (maintenance, third parties) that the promise means little."]],"related":[{"href":"/glossary/slo","label":"SLO (service level objective)","detail":"An internal reliability target for a service, such as 99.9% of requests succeeding, measured by a service level indicator (SLI)."},{"href":"/glossary/uptime","label":"Uptime","detail":"The share of time a service is working and reachable, usually written as a percentage such as 99.9%."},{"href":"/glossary/rto","label":"RTO (recovery time objective)","detail":"How long a system can stay down after a failure before the outage seriously harms the business."},{"href":"/glossary/rpo","label":"RPO (recovery point objective)","detail":"The point in time to which data must be recoverable after an outage: in practice, how much recent data you can afford to lose."}],"tools":[{"href":"/tools/software-maintenance-cost","label":"Software maintenance cost","detail":"Free tool"}],"links":[{"href":"/software","label":"Software by industry","detail":"Systems we build per industry, with guides and tools."},{"href":"/compliance/soc-2","label":"SOC 2 guide","detail":"The controls behind a SOC 2 report."}],"sources":[{"title":"Google SRE book, Service Level Objectives","url":"https://sre.google/sre-book/service-level-objectives/","checkedAt":"2026-10-25"}],"legal":false,"updatedAt":"2026-10-25"}