Prometheus: Collects metrics, provides alerting and graphs web UI

Prometheus provides a solution for collecting metrics from systems and applications and aggregating them into a central location.

Rules can be defined in the main server to send alerts to the operations team. A web GUI displays the alerts and graphs from the collected metrics.

Auto Discovery

Prometheus is cloud friendly, and integrates with cloud discovery components such as:

  • DNS SRV records
  • Consul
  • AWS EV2
  • Google Cloud
  • Kubernetes
  • Mesospher Marathon
  • AirBNB Nerve
  • Zooeeper
  • Triton
  • File based – scans a directory of files every few seconds for updates.

It is written in Go and contained in a single executable file.


Prometheus aggregates the metrics from the servers to a central server using pull requests to the agents running on the servers.

Agents are called “exporters” and used export the metrics as HTTP using REST.

Below are the types of exporters:

Time server data store

Prometheus uses its internal time series data store for the collected metrics.


The list of current exports can be found here:

Notable exporters:

  • Node exporter
    Comes as part of Prometheus. Exports OS related information such as CPU load, disk space, RAM, etc.
    It can also track values in files. This is useful for short living jobs running from cron.
  • Script exporter
    Collects metrics based on script exit codes and time taken to run.
  • Blackbox exporter
    Collects metrics from HTTP, TCP, DNS and ICMP, based on pattern matching rules.
  • Consul
  • CouchDB
  • MySQL
  • Redis
  • RabbitMQ
  • Ceph
  • GlusterFS
  • Apache httpd
  • HAProxy
  • Nginx
  • AWS
  • Docker
  • Collectd
  • AWS CloudWatch
  • Graphite
  • InfluxDB
  • StatsD

Software that has built in exporters

Full list can be found here:

  • cAdvisor
  • Doorman
  • Etcd
  • Kubernetes-Mesos
  • Kubernetes
  • RobustIRC
  • SkyDNS

Notifications (Alerts)

Prometheus support alerting, and enables the administrator to define rules on the central server.

After passing the rules, the alerts are sent to a component called Alertsmanager, which is in charge of silencing, de-duplication, and sending the alerts via email, PagerDuty, Slack etc.

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