Prometheus
Monitoring and alerting toolkit that scrapes metrics and stores them as time series, queried with PromQL.
Observability
Prometheus is a systems monitoring and alerting toolkit built at SoundCloud in 2012 and now a graduated Cloud Native Computing Foundation project, so it is maintained independently of any single vendor. It scrapes metrics over HTTP on a pull model, stores them locally as time series identified by metric name and key/value labels, and answers questions in PromQL; alerting rules live in the same server. It runs as a single static binary with no external dependencies, and is installed from precompiled binaries, from source, or from the official container images. There is one edition: the Apache-2.0 self-hosted server, at no cost, with no paid tier and no vendor cloud. The honest trade-off is storage and scope: the built-in time series database is documented as not clustered and not replicated, so it is not durable against a node or drive outage and long-term storage means adding another system, and the project's own FAQ puts logs out of scope.
Key features
- Multi-dimensional data model of metric names and key/value labels
- PromQL query language over the stored time series
- Time series collected by scraping targets over HTTP
- Targets found by service discovery or listed in a static config
- Push gateway for short-lived jobs that cannot be scraped
- Runs as a single binary with no external dependencies
- Retention time and size set by command-line flags
Self-hosted editions
- Self-hosted (Apache-2.0)Free self-hosted
- LicenceOpen source · Apache-2.0DeploymentSelf-hosted
Limits, notes & source
Self-hosted (Apache-2.0)
- Limits
- The complete server and toolkit: scraping, the local time series database, PromQL, alerting rules and the Alertmanager, with no seat limit and no paid edition.
- Notes
- The project FAQ states "Prometheus is released under the Apache 2.0 license" and points at the repository LICENSE; GitHub's licence API reads that file as "Apache License 2.0", spdx_id "Apache-2.0". No price is published on prometheus.io because no paid edition exists — the project sells nothing.
Pros & cons
Strengths
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