What is PromQL and what is its role in the Prometheus system?

PromQL is short for Prometheus Query Language, which is a language widely used in the Prometheus monitoring system for querying and analyzing data.

PromQL can be used to query and filter data from the time-series database of a Prometheus server, perform aggregation operations, calculate statistical metrics, generate reports, and more. It supports flexible filtering and grouping operations to help users quickly and accurately find the data they need.

By using PromQL, users can easily create complex monitoring and alerting rules, conduct in-depth analysis of monitoring data, and monitor the performance and health of the system. The flexibility and powerful features of PromQL allow users to customize monitoring and alerting strategies according to their needs, enabling real-time monitoring and management of system performance and health status.