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Apache HTTP Server

The OpenTelemetry Collector's Apache receiver collects 13 metrics from Apache HTTP Server 2.4.13+, including request rates, traffic throughput, worker status, CPU usage, and system load averages. This guide configures the receiver, enables the required mod_status endpoint, and ships metrics to base14 Scout.

Prerequisites​

RequirementMinimumRecommended
Apache HTTP Server2.4.132.4.x
OTel Collector Contrib0.90.0latest
base14 ScoutAny—

Before starting:

  • Apache must be accessible from the host running the Collector
  • mod_status module loaded with ExtendedStatus On
  • OTel Collector installed — see Docker Compose Setup

What You'll Monitor​

  • Requests: total request count, request processing time
  • Traffic: bytes served, current connections, async connection states
  • Workers: busy/idle workers, scoreboard slot states
  • CPU: CPU load percentage, user/system CPU time
  • System: 1/5/15-minute load averages, server uptime

Full metric reference: OTel Apache Receiver

Access Setup​

Enable mod_status in your Apache configuration:

httpd-status.conf
# Enable extended status for full metrics
ExtendedStatus On

# Expose the status endpoint
<Location "/server-status">
    SetHandler server-status
    # Restrict access to monitoring network
    Require ip 10.0.0.0/8 172.16.0.0/12 192.168.0.0/16
</Location>

mod_status is loaded by default in most Apache installations. If not, add LoadModule status_module modules/mod_status.so before the block above.

Verify the endpoint returns machine-readable data:

curl -s http://localhost/server-status?auto

Configuration​

config/otel-collector.yaml
receivers:
  apache:
    endpoint: http://localhost/server-status?auto   # Change to your Apache URL
    collection_interval: 30s

    metrics:
      # Connections
      apache.connections.async:
        enabled: true
      apache.current_connections:
        enabled: true

      # Requests and traffic
      apache.requests:
        enabled: true
      apache.request.time:
        enabled: true
      apache.traffic:
        enabled: true

      # Workers
      apache.workers:
        enabled: true
      apache.scoreboard:
        enabled: true

      # CPU
      apache.cpu.load:
        enabled: true
      apache.cpu.time:
        enabled: true

      # System load
      apache.load.1:
        enabled: true
      apache.load.5:
        enabled: true
      apache.load.15:
        enabled: true

      # Uptime
      apache.uptime:
        enabled: true

processors:
  resource:
    attributes:
      - key: environment
        value: ${env:ENVIRONMENT}
        action: upsert
      - key: service.name
        value: ${env:SERVICE_NAME}
        action: upsert

  batch:
    timeout: 10s
    send_batch_size: 1024

# Export to base14 Scout
exporters:
  otlphttp/b14:
    endpoint: ${env:OTEL_EXPORTER_OTLP_ENDPOINT}
    tls:
      insecure_skip_verify: true

service:
  pipelines:
    metrics:
      receivers: [apache]
      processors: [resource, batch]
      exporters: [otlphttp/b14]

Environment Variables​

.env
ENVIRONMENT=your_environment
SERVICE_NAME=your_service_name
OTEL_EXPORTER_OTLP_ENDPOINT=https://<your-tenant>.base14.io

Verify the Setup​

Start the Collector and check for metrics within 60 seconds:

# Check Collector logs for successful scrape
docker logs otel-collector 2>&1 | grep -i "apache"

# Verify server-status endpoint responds
curl -s http://localhost/server-status?auto

# Check mod_status is loaded
apachectl -M 2>&1 | grep status

Troubleshooting​

403 Forbidden on server-status​

Cause: The Require directive restricts access and the Collector's IP is not allowed.

Fix:

  1. Add the Collector's IP to the Require ip list in the <Location> block
  2. For Docker setups, use the container network CIDR (e.g., Require ip 172.16.0.0/12)
  3. Restart Apache after changing the config: apachectl graceful

No metrics or partial metrics​

Cause: ExtendedStatus is not enabled, so only basic metrics are returned.

Fix:

  1. Add ExtendedStatus On before the <Location> block
  2. Verify by checking the output of curl -s http://localhost/server-status?auto — it should include Total Accesses, CPULoad, and ReqPerSec
  3. Restart Apache: apachectl graceful

No metrics appearing in Scout​

Cause: Metrics are collected but not exported.

Fix:

  1. Check Collector logs for export errors: docker logs otel-collector
  2. Verify OTEL_EXPORTER_OTLP_ENDPOINT is set correctly
  3. Confirm the pipeline includes both the receiver and exporter

Load average metrics showing zero on non-Linux​

Cause: apache.load.1, apache.load.5, and apache.load.15 rely on system load averages exposed by Apache, which may not be available on all operating systems.

Fix:

  1. These metrics are populated on Linux systems where Apache reports system load in server-status
  2. On macOS or Windows, these may report zero — this is expected behavior
  3. Use OS-level monitoring for load averages on non-Linux platforms

FAQ​

Does this work with Apache running in Kubernetes?

Yes. Set endpoint to the Apache service DNS (e.g., http://apache.default.svc.cluster.local/server-status?auto) and ensure mod_status allows access from the Collector pod's network. The Collector can run as a sidecar or DaemonSet.

How do I monitor multiple Apache instances?

Add multiple receiver blocks with distinct names:

receivers:
  apache/web1:
    endpoint: http://web-1/server-status?auto
  apache/web2:
    endpoint: http://web-2/server-status?auto

Then include both in the pipeline: receivers: [apache/web1, apache/web2]

Is mod_status already loaded by default?

In most Apache installations (including the official Docker image), mod_status is loaded by default. You only need to add the <Location> block and ExtendedStatus On. Check with apachectl -M | grep status.

What is the scoreboard metric?

apache.scoreboard tracks the state of each Apache worker slot: waiting, reading, sending, keepalive, DNS lookup, closing, logging, graceful finish, idle cleanup, or open. It gives a real-time view of how Apache is distributing work across its worker pool.

What's Next?​

  • Create Dashboards: Explore pre-built dashboards or build your own. See Create Your First Dashboard
  • Monitor More Components: Add monitoring for NGINX, HAProxy, and other components
  • Fine-tune Collection: Adjust collection_interval based on your traffic patterns
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