Redis Metrics Exporter

Prometheus exporter for Redis metrics.
Supports Redis 2.x, 3.x, 4.x, and 5.x

Upgrading from 0.x to 1.x?

PR #256 introduced breaking changes which were released as version v1.0.0.

If you only scrape one Redis instance and use command line flags --redis.address and --redis.password then you're most probably not affected. Otherwise, please see PR #256 and this README for more information.

Build and run locally

    $ go get github.com/oliver006/redis_exporter
    $ cd $GOPATH/src/github.com/oliver006/redis_exporter
    $ go build
    $ ./redis_exporter <flags>

Configuring

Basic Prometheus Configuration

Add a block to the scrape_configs of your prometheus.yml config file:

scrape_configs:
  - job_name: redis_exporter
    static_configs:
    - targets: ['<<REDIS-EXPORTER-HOSTNAME>>:9121']

and adjust the host name accordingly.

Prometheus Configuration to Scrape Multiple Redis Hosts

Run the exporter with the command line flag --redis.addr= so it won't try to access the local instance every time the /metrics endpoint is scraped.

scrape_configs:
  ## config for the multiple Redis targets that the exporter will scrape
  - job_name: 'redis_exporter_targets'
    static_configs:
      - targets:
        - redis://first-redis-host:6379
        - redis://second-redis-host:6379
        - redis://second-redis-host:6380
        - redis://second-redis-host:6381
    metrics_path: /scrape
    relabel_configs:
      - source_labels: [__address__]
        target_label: __param_target
      - source_labels: [__param_target]
        target_label: instance
      - target_label: __address__
        replacement: <<REDIS-EXPORTER-HOSTNAME>>:9121
  
  ## config for scraping the exporter itself
  - job_name: 'redis_exporter'
    static_configs:
      - targets:
        - <<REDIS-EXPORTER-HOSTNAME>>:9121

The Redis instances are listed under targets, the Redis exporter hostname is configured via the last relabel_config rule.
If authentication is needed for the Redis instances then you can set the password via the --redis.password command line option of the exporter (this means you can currently only use one password across the instances you try to scrape this way. Use several exporters if this is a problem).
You can also use a file supply multiple targets by using file_sd_configs like so:

scrape_configs:
  - job_name: 'redis_exporter'
    file_sd_configs:
      - files:
        - targets-redis-instances.json
    metrics_path: /scrape
    relabel_configs:
      - source_labels: [__address__]
        target_label: __param_target
      - source_labels: [__param_target]
        target_label: instance
      - target_label: __address__
        replacement: <<REDIS-EXPORTER-HOSTNAME>>:9121

The targets-redis-instances.json should look something like this:

[
  {
    "targets": [ "redis-host-01:6379", "redis-host-02:6379"],
    "labels": { }
  }
]

Prometheus uses file watches and all changes to the json file are applied immediately.

Running

Flags

Redis instance addresses can be tcp addresses: redis://localhost:6379, redis.example.com:6379 or e.g. unix sockets: unix:///tmp/redis.sock.
SSL is supported by using the rediss:// schema, for example: rediss://azure-ssl-enabled-host.redis.cache.windows.net:6380 (note that the port is required when connecting to a non-standard 6379 port, e.g. with Azure Redis instances).
Password-protected instances can be accessed by using the URI format including a password: redis://h:<<PASSWORD>>@<<HOSTNAME>>:<<PORT>>

Command line settings take precedence over any configurations provided by the environment variables.

Run via Docker

The latest release is automatically published to the Docker registry.

You can run it like this:

    $ docker run -d --name redis_exporter -p 9121:9121 oliver006/redis_exporter

The latest docker image contains only the exporter binary. If, e.g. for debugging purposes, you need the exporter running in an image that has a shell, etc then you can run the alpine image:

    $ docker run -d --name redis_exporter -p 9121:9121 oliver006/redis_exporter:alpine

If you try to access a Redis instance running on the host node, you'll need to add --network host so the redis_exporter container can access it:

    $ docker run -d --name redis_exporter --network host oliver006/redis_exporter

Run on Kubernetes

Here is an example Kubernetes deployment configuration for how to deploy the redis_exporter as a sidecar to a Redis instance.

What's exported?

Most items from the INFO command are exported, see https://redis.io/commands/info for details.
In addition, for every database there are metrics for total keys, expiring keys and the average TTL for keys in the database.
You can also export values of keys if they're in numeric format by using the -check-keys flag. The exporter will also export the size (or, depending on the data type, the length) of the key. This can be used to export the number of elements in (sorted) sets, hashes, lists, streams, etc.

If you require custom metric collection, you can provide a Redis Lua script using the -script flag. An example can be found in the contrib folder.

What does it look like?

Example Grafana screenshots:

Grafana dashboard is available on grafana.net and/or github.com.

What else?

Open an issue or PR if you have more suggestions, questions or ideas about what to add.

Troubleshooting / Known issues

#282 check-keys parameter is not working in latest build. You will need to add parameter to Prometheus like

scrape_configs:
  ## config for the multiple Redis targets that the exporter will scrape
  - job_name: 'redis_exporter_targets'
    static_configs:
      - targets:
        - redis://first-redis-host:6379
        - redis://second-redis-host:6379
    metrics_path: /scrape
    params:
      check-keys: ["metrics:*"]