VictoriaMetrics/app/vmalert/README.md

VM Alert

vmalert executes a list of given MetricsQL expressions (rules) and sends alerts to Alert Manager.

NOTE: vmalert is in early alpha and wasn't tested in production systems yet.

Features:

• Integration with VictoriaMetrics TSDB;
• VictoriaMetrics MetricsQL expressions validation;
• Prometheus alerting rules definition format support;
• Integration with Alertmanager;
• Lightweight without extra dependencies.

TODO:

• Persist alerts state as timeseries in TSDB. Currently, alerts state is stored in process memory only and will be lost on restart;
• Configuration hot reload.

QuickStart

To build vmalert from sources:

git clone https://github.com/VictoriaMetrics/VictoriaMetrics
cd VictoriaMetrics
make vmalert

The build binary will be placed to VictoriaMetrics/bin folder.

To start using vmalert you will need the following things:

• list of alert rules - PromQL/MetricsQL expressions to execute;
• datasource address - reachable VictoriaMetrics instance for rules execution;
• notifier address - reachable Alertmanager instance for processing, aggregating alerts and sending notifications.

Then configure vmalert accordingly:

./bin/vmalert -rule=alert.rules \
		-datasource.url=http://localhost:8428 \
        -notifier.url=http://localhost:9093

Example for .rules file may be found here

vmalert runs evaluation for every group in a separate goroutine. Rules in group evaluated one-by-one sequentially.

vmalert also runs a web-server (-httpListenAddr) for serving metrics and alerts endpoints:

• http://<vmalert-addr>/api/v1/alerts - list of all active alerts;
• http://<vmalert-addr>/api/v1/<groupName>/<alertID>/status" - get alert status by ID. Used as alert source in AlertManager.
• http://<vmalert-addr>/metrics - application metrics.

Configuration

The shortlist of configuration flags is the following:

Usage of vmalert:
  -datasource.url string
        Victoria Metrics or VMSelect url. Required parameter. e.g. http://127.0.0.1:8428
  -datasource.basicAuth.password string
        Optional basic auth password to use for -datasource.url
  -datasource.basicAuth.username string
        Optional basic auth username to use for -datasource.url
  -evaluationInterval duration
        How often to evaluate the rules. Default 1m (default 1m0s)
  -external.url string
        External URL is used as alert's source for sent alerts to the notifier
  -httpListenAddr string
        Address to listen for http connections (default ":8880")
  -notifier.url string
        Prometheus alertmanager URL. Required parameter. e.g. http://127.0.0.1:9093
  -remotewrite.url string
        Optional URL to remote-write compatible storage where to write timeseriesbased on active alerts. E.g. http://127.0.0.1:8428
  -rule value
        Path to the file with alert rules. 
        Supports patterns. Flag can be specified multiple times. 
        Examples:
         -rule /path/to/file. Path to a single file with alerting rules
         -rule dir/*.yaml -rule /*.yaml. Relative path to all .yaml files in "dir" folder, 
        absolute path to all .yaml files in root.
  -rule.validateTemplates
        Indicates to validate annotation and label templates (default true)

Pass -help to vmalert in order to see the full list of supported command-line flags with their descriptions.

Contributing

vmalert is mostly designed and built by VictoriaMetrics community. Feel free to share your experience and ideas for improving this software. Please keep simplicity as the main priority.