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Monitoring

Monitor your self-hosted Primary Site using Prometheus.

Configure Prometheus

The Primary Site services expose various application metrics that Prometheus can scrape and ingest.

The first option is to use one of the major cloud providers' managed integrations:

Alternatively, deploy Prometheus to your cluster directly using the directions below.

Create Helm repositories and namespace

Add Prometheus Helm repositories:

$ helm repo add prometheus-community https://prometheus-community.github.io/helm-charts
$ helm repo update

Create a Kubernetes namespace for Prometheus:

$ kubectl create namespace prometheus

Install Prometheus

Install Prometheus to your Kubernetes cluster:

$ helm install prometheus prometheus-community/prometheus -n prometheus

Configure pods for scraping

Locate the streamService, siteController, and inboxListener sections in your values.yaml file.

For each section, add a pod annotation under deployment instructing Prometheus to scrape the pod:

siteController:
deployment:
podAnnotations:
prometheus.io/scrape: true

Upgrade your deployment with the new configuration. You may need to alter this command with your own namespace, Helm release name, and file path:

$ helm upgrade primary-site -f values.yaml --namespace foxglove

Prometheus will now scrape the metrics endpoints of the deployed services. To confirm this is working, forward the port of the Prometheus UI to view collected metrics:

$ kubectl -n prometheus port-forward service/prometheus-server 9090:80

Visit http://localhost:9090 and enter the query {app="site-controller"}. Executing that should show a list of metrics scraped from the edge controller.

Install custom metrics adapter

Finally, install the Prometheus adapter for the Kubernetes custom metrics API using Helm.

This assumes you have installed Prometheus into the "prometheus" namespace. If you are using a different namespace, replace the second component of the URL accordingly.

$ helm install prometheus-custom-metrics-adapter prometheus-community/prometheus-adapter -n prometheus --set prometheus.url=http://prometheus-server.prometheus.svc.cluster.local

After a couple minutes, you should see custom metrics:

$ kubectl get --raw /apis/custom.metrics.k8s.io/v1beta1

If the output contains metrics, you are ready to create an autoscaler on custom metrics.

Monitor metrics

Once Prometheus is configured, the services expose useful application metrics for monitoring.

Stream service

  • stream_sync_ms - Time between reception of request and establishment of connections to all immediately-required objects in storage (histogram)
  • time_to_first_message_ms - Time between reception of request and first message written out (histogram)
  • files_request_latency_ms - Time to request list of data files from Foxglove API (histogram)

Inbox listener

  • import_success_count - Number of imports successfully processed (counter)
  • import_quarantine_count - Number of imports quarantined (counter)
  • import_input_size_bytes - Size of input files in bytes (histogram)
  • import_output_size_bytes - Size of output files (processed data files) in bytes (histogram)
  • import_processing_time_seconds - Processing time for imports in seconds (histogram)
  • output_file_count - Number of output files per import (histogram)
  • input_message_count - Number of messages per import (histogram)

Site controller

  • unleased_pending_import_count - Number of backlogged pending imports for processing (gauge)
  • oldest_unprocessed_pending_import_age_secs - Age of oldest unprocessed pending import in seconds (gauge)