DevOps Dictionary

Uptime is the amount of time a system (such as an API, database, or application) is available and working as expected, commonly reported as a percentage over a defined window (for example, monthly uptime). It addresses the core reliability problem of ensuring users and dependent services can access critical functionality when they need it. At a high level, uptime is tracked by monitoring checks that continuously verify health and responsiveness; outages are recorded when those checks fail, and teams reduce downtime through redundancy, automated recovery, and careful change management.

With uptime targets and measurement in place, teams can set clear reliability expectations, detect incidents quickly, and prioritize fixes that prevent repeat failures; without it, availability becomes guesswork, leading to longer outages, broken integrations, and missed service-level commitments. This gap exists because modern systems fail in many small ways—deployments, dependencies, capacity limits—that only consistent measurement and response can control.