startuptime

Startuptime is the duration between the initiation of a system, application, or service and the moment it becomes usable or fully ready to handle input. It is a key performance parameter in operating systems, software applications, and online services, as shorter startup times can improve perceived responsiveness and throughput.

In an operating system, startup time refers to the period from power-on or reboot until the system reaches a usable state, including user authentication and desktop readiness. In software development, startup time typically means the interval from process launch or request receipt to the point where the application can process user interactions or serve responses. This can be measured for cold starts (first launch after a clean state) or warm starts (subsequent launches with cached state).

Measurement and metrics: Startuptime is typically defined by a start moment and a completion moment. Common measurements include boot time, application startup time, time to interactive, and perceived startup time. Tools and approaches include boot charts, profiling during initialization, real-user monitoring, and synthetic benchmarks. In web contexts, related concepts include time to first byte, first contentful paint, and time to interactive.

Factors influencing startuptime encompass hardware performance (CPU, memory, disk speed), software architecture (initialization order, dependencies), operating system services, I/O contention, network latency for remote resources, and the use of caching or preloading. Containerization and virtualization overhead can also affect startup times.

Optimization strategies focus on reducing blocking work during startup, enabling parallel initialization, lazy loading of noncritical components, startup prewarming, caching and persisted state, and reducing external dependencies. Profiling and benchmarking are essential to identify bottlenecks and verify improvements over time.