Do I need to install prometheus in my cluster in order to scrape metrics into Otel?

[mmoya91]

Hello, I have a python service that includes a prometheus client and /metrics endpoint for those metrics. That said, do I need to install prometheus in my cluster in order to scrape those metrics into the otel collector? I noticed documentation around setting up a prometheus receiver but not sure if that would involve standing up prometheus

[github-actions]

Pinging code owners for receiver/prometheus: @Aneurysm9 @dashpole. See Adding Labels via Comments if you do not have permissions to add labels yourself.

[dashpole]

No, you can just run the OpenTelemetry collector with the prometheus receiver if your goal is to scrape metrics from the application. But note that the OpenTelemetry collector is just for transforming and routing telemetry, not for storing telemetry. You still need to choose which backend to store telemetry in. The prometheus server (not the otel collector) scrapes and stores metrics.

[mmoya91]

@dashpole thank you for your reply. We're ultimately looking to store metrics in datadog but some of our applications use prometheus metrics instead of fastapi metrics. For applications that use fastapi metrics, we're deploying Otel Collector as a sidecar. However, for services that use prometheus metrics, would we need to consider a StatefulSet as the deployment mode for the prometheus receiver or could we consider a sidecar deployment?

[dashpole]

You can use the prometheus receiver in the collector as a sidecar without issues. You will want to use static_configs within the prometheus receiver configuration, e.g.

receivers:
    prometheus:
      config:
        scrape_configs:
          - job_name: 'otel-collector'
            scrape_interval: 5s
            static_configs:
              - targets: ['0.0.0.0:8888']

[github-actions]

This issue has been inactive for 60 days. It will be closed in 60 days if there is no activity. To ping code owners by adding a component label, see Adding Labels via Comments, or if you are unsure of which component this issue relates to, please ping @open-telemetry/collector-contrib-triagers. If this issue is still relevant, please ping the code owners or leave a comment explaining why it is still relevant. Otherwise, please close it.

Pinging code owners:

• receiver/prometheus: @Aneurysm9 @dashpole

See Adding Labels via Comments if you do not have permissions to add labels yourself.

[dashpole]

Closing. If you still have questions, feel free to reopen.