PureLB exposes Prometheus metrics from both the Allocator and LBNodeAgent on port 7472 at /metrics.

Metrics#

All metrics are documented in the Metrics Reference. Key metrics to watch:

• Pool exhaustion: purelb_address_pool_addresses_in_use vs purelb_address_pool_size
• Election health: purelb_election_lease_healthy, purelb_election_member_count
• Node agent activity: purelb_lbnodeagent_garp_errors_total, purelb_lbnodeagent_address_additions_total

Setting Up Prometheus#

ServiceMonitor (Prometheus Operator)#

If using the Prometheus Operator, enable ServiceMonitors via Helm:

Prometheus:
  allocator:
    Metrics:
      enabled: true
    serviceMonitor:
      enabled: true
  lbnodeagent:
    Metrics:
      enabled: true
    serviceMonitor:
      enabled: true

Or apply the ServiceMonitor manifests directly from the repository’s monitoring/service-monitors.yaml.

PrometheusRules#

Example alert for pool exhaustion:

Prometheus:
  allocator:
    prometheusRules:
      enabled: true
      rules:
      - alert: PureLBPoolNearlyExhausted
        expr: purelb_address_pool_addresses_in_use / purelb_address_pool_size > 0.9
        for: 5m
        labels:
          severity: warning
        annotations:
          summary: "Pool {{ $labels.pool }} is over 90% utilized"

Useful PromQL Queries#

Pool utilization percentage:

purelb_address_pool_addresses_in_use / purelb_address_pool_size * 100

Unhealthy nodes:

purelb_election_lease_healthy == 0

GARP error rate:

rate(purelb_lbnodeagent_garp_errors_total[5m])

Address churn rate:

rate(purelb_lbnodeagent_address_additions_total[5m]) + rate(purelb_lbnodeagent_address_withdrawals_total[5m])

Grafana Dashboard#

A pre-built Grafana dashboard is available at monitoring/dashboard.json in the PureLB repository. It shows pool utilization tables and node agent health.

Terminal Monitoring#

For quick monitoring without Prometheus:

kubectl purelb dashboard

This shows a live terminal view of pool status, election health, and BGP sessions.