Uptime Glossary

DigitalOcean Uptime is a monitoring service that checks the health of any URL or IP address. You can use it to monitor the latency, uptime, and SSL certificate of any website or host, and can choose to receive alerts via email or Slack when your site is down, experiencing high latency, or has an SSL certificate that’s about to expire. Learn more about Uptime.


This glossary defines the core concepts behind uptime monitoring to help build your mental model of how monitoring works and understand what the documentation is referring to when it uses certain terminology.

An alert interval is the period of time that average usage must exceed a threshold before triggering an alert.
Alerting within a computer monitoring system is the ability to send notifications when certain metrics fall outside of expected ranges.
A health check is a scheduled HTTP or TCP request that you can configure to run on a repeating basis to ensure that a service is healthy.
Internet Control Message Protocol (ICMP) is a network layer protocol used to diagnose problems between devices within a network.
In computing, monitoring is the process of gathering and visualizing data to improve awareness of system health and minimize response time when usage is outside of expected levels.
SSL certificate is a digital document outlining the identity of the website.
In alerting, a threshold is a value that defines the boundary between normal and abnormal usage.
A trend indicates a general tendency in a data set over time. Trends are useful for recognizing changes and for predicting future behavior.