Alertmanager

The Alertmanager handles alerts sent by client applications such as the Prometheus server. It takes care of deduplicating, grouping, and routing them to the correct receiver integrations such as email, PagerDuty, or OpsGenie. It also takes care of silencing and inhibition of alerts.

Documentation

Install

There are various ways of installing Alertmanager.

Precompiled binaries

Precompiled binaries for released versions are available in the download section on prometheus.io. Using the latest production release binary is the recommended way of installing Alertmanager.

Docker images

Docker images are available on Quay.io.

Compiling the binary

You can either go get it:

$ GO15VENDOREXPERIMENT=1 go get github.com/prometheus/alertmanager/cmd/...
# cd $GOPATH/src/github.com/prometheus/alertmanager
$ alertmanager -config.file=<your_file>

Or checkout the source code and build manually:

$ mkdir -p $GOPATH/src/github.com/prometheus
$ cd $GOPATH/src/github.com/prometheus
$ git clone https://github.com/prometheus/alertmanager.git
$ cd alertmanager
$ make build
$ ./alertmanager -config.file=<your_file>

Example

This is an example configuration that should cover most relevant aspects of the new YAML configuration format. The full documentation of the configuration can be found here.

global:
  # The smarthost and SMTP sender used for mail notifications.
  smtp_smarthost: 'localhost:25'
  smtp_from: 'alertmanager@example.org'

# The root route on which each incoming alert enters.
route:
  # The root route must not have any matchers as it is the entry point for
  # all alerts. It needs to have a receiver configured so alerts that do not
  # match any of the sub-routes are sent to someone.
  receiver: 'team-X-mails'
  
  # The labels by which incoming alerts are grouped together. For example,
  # multiple alerts coming in for cluster=A and alertname=LatencyHigh would
  # be batched into a single group.
  group_by: ['alertname', 'cluster']

  # When a new group of alerts is created by an incoming alert, wait at
  # least 'group_wait' to send the initial notification.
  # This way ensures that you get multiple alerts for the same group that start
  # firing shortly after another are batched together on the first
  # notification.
  group_wait: 30s

  # When the first notification was sent, wait 'group_interval' to send a batch
  # of new alerts that started firing for that group.
  group_interval: 5m

  # If an alert has successfully been sent, wait 'repeat_interval' to
  # resend them.
  repeat_interval: 3h

  # All the above attributes are inherited by all child routes and can 
  # overwritten on each.

  # The child route trees.
  routes:
  # This routes performs a regular expression match on alert labels to
  # catch alerts that are related to a list of services.
  - match_re:
      service: ^(foo1|foo2|baz)$
    receiver: team-X-mails

    # The service has a sub-route for critical alerts, any alerts
    # that do not match, i.e. severity != critical, fall-back to the
    # parent node and are sent to 'team-X-mails'
    routes:
    - match:
        severity: critical
      receiver: team-X-pager

  - match:
      service: files
    receiver: team-Y-mails

    routes:
    - match:
        severity: critical
      receiver: team-Y-pager

  # This route handles all alerts coming from a database service. If there's
  # no team to handle it, it defaults to the DB team.
  - match:
      service: database

    receiver: team-DB-pager
    # Also group alerts by affected database.
    group_by: [alertname, cluster, database]

    routes:
    - match:
        owner: team-X
      receiver: team-X-pager

    - match:
        owner: team-Y
      receiver: team-Y-pager


# Inhibition rules allow to mute a set of alerts given that another alert is
# firing.
# We use this to mute any warning-level notifications if the same alert is
# already critical.
inhibit_rules:
- source_match:
    severity: 'critical'
  target_match:
    severity: 'warning'
  # Apply inhibition if the alertname is the same.
  equal: ['alertname']


receivers:
- name: 'team-X-mails'
  email_configs:
  - to: 'team-X+alerts@example.org'

- name: 'team-X-pager'
  email_configs:
  - to: 'team-X+alerts-critical@example.org'
  pagerduty_configs:
  - service_key: <team-X-key>

- name: 'team-Y-mails'
  email_configs:
  - to: 'team-Y+alerts@example.org'

- name: 'team-Y-pager'
  pagerduty_configs:
  - service_key: <team-Y-key>

- name: 'team-DB-pager'
  pagerduty_configs:
  - service_key: <team-DB-key>

High Availability

Warning: High Availablility is under active development

To create a highly available cluster of the Alertmanager the instances need to be configured to communicate with each other. This is configured using the -mesh.* flags.

-mesh.hardware-address string: MAC address, i.e. mesh peer ID (default "<hardware-mac-address>")
-mesh.listen-address string: mesh listen address (default "0.0.0.0:6783")
-mesh.nickname string: peer nickname (default "<machine-hostname>")
-mesh.peer value: initial peers (may be repeated)

The mesh.hardware-address flag is used as a unique ID among the peers. It defaults to the MAC address, therefore the default value should typically be a good option. The same applies to the default of the mesh.nickname flag, as it defaults to the hostname. The chosen port in the mesh.listen-address flag is the port that needs to be specified in the mesh.peer flag of the other peers.

To start a cluster of three peers on your local machine use goreman and the Procfile within this repository.

goreman start

To point your prometheus instance to multiple Alertmanagers use the -alertmanager.url parameter. It allows passing in a comma separated list. Start your prometheus like this, for example:

./prometheus -config.file=prometheus.yml -alertmanager.url http://localhost:9095,http://localhost:9094,http://localhost:9093

Note: make sure to have a valid prometheus.yml in your current directory

shredder12 / alertmanager