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Apache HTTP Server

Collect request rate, worker utilisation, scoreboard state, and traffic metrics from Apache HTTP Server using apache_exporter.

Pattern: apache_exporter → Prometheus scrape → xScaler remote_write

Dashboard​

Dashboard

Prerequisites​

  • Apache HTTP Server 2.4 or later with mod_status enabled
  • Prometheus or Grafana Alloy
  • xScaler tenant credentials

Step 1 — Enable mod_status​

Add or verify the following in your Apache config (e.g. /etc/apache2/conf-available/status.conf):

<Location "/server-status">
  SetHandler server-status
  Require local
</Location>

ExtendedStatus On

Enable the config and reload:

# Debian/Ubuntu
a2enmod status
a2enconf status
systemctl reload apache2

# RHEL/CentOS
systemctl reload httpd

Verify:

curl http://localhost/server-status?auto
# Total Accesses: 1234
# Total kBytes: 5678
# ...

Step 2 — Run apache_exporter​

docker run --rm -d \
  --name apache-exporter \
  --network host \
  -p 9117:9117 \
  lusotycoon/apache-exporter \
  --scrape_uri=http://localhost/server-status?auto

Verify:

curl -s http://localhost:9117/metrics | grep apache_up
# apache_up 1

Step 3 — Scrape and forward to xScaler​

Prometheus​

scrape_configs:
  - job_name: apache
    static_configs:
      - targets: ['localhost:9117']
        labels:
          instance: web-01

remote_write:
  - url: https://euw1-01.m.xscalerlabs.com/api/v1/push
    authorization:
      credentials: <token>
    headers:
      X-Scope-OrgID: <tenant-id>

Grafana Alloy​

prometheus.scrape "apache" {
  targets    = [{"__address__" = "localhost:9117"}]
  forward_to = [prometheus.remote_write.xscaler.receiver]
}

prometheus.remote_write "xscaler" {
  endpoint {
    url = "https://euw1-01.m.xscalerlabs.com/api/v1/push"
    authorization {
      type        = "Bearer"
      credentials = "<token>"
    }
    headers = { "X-Scope-OrgID" = "<tenant-id>" }
  }
}

OpenTelemetry Collector​

receivers:
  apache:
    endpoint: http://localhost/server-status?auto
    collection_interval: 15s

processors:
  memory_limiter:
    check_interval: 1s
    limit_mib: 256
  batch:
    timeout: 10s

exporters:
  otlphttp/xscaler:
    endpoint: https://euw1-01.m.xscalerlabs.com
    headers:
      Authorization: "Bearer <token>"
      X-Scope-OrgID: "<tenant-id>"

service:
  pipelines:
    metrics:
      receivers:  [apache]
      processors: [memory_limiter, batch]
      exporters:  [otlphttp/xscaler]

Logs​

Collect Apache access log and error log. Add the following to your Alloy config:

local.file_match "apache_logs" {
  path_targets = [{
    __address__ = "localhost",
    __path__    = "/var/log/apache2/access.log",
    instance    = constants.hostname,
    job         = "integrations/apache_http",
  }]
}

loki.source.file "apache_logs" {
  targets    = local.file_match.apache_logs.targets
  forward_to = [loki.write.xscaler.receiver]
}

loki.write "xscaler" {
  endpoint {
    url = "https://euw1-01.l.xscalerlabs.com/api/v1/logs/push"

    http_client_config {
      authorization {
        type        = "Bearer"
        credentials = env("XSCALER_TOKEN")
      }
    }

    headers = { "X-Scope-OrgID" = env("XSCALER_TENANT_ID") }
  }
}

Key metrics​

MetricDescription
apache_upExporter reachability (1 = up)
apache_accesses_totalTotal number of HTTP accesses
apache_sent_kilobytes_totalTotal kBytes sent
apache_workersWorker count by state (busy, idle)
apache_scoreboardScoreboard slot counts by state
apache_cpuloadCPU load of the Apache process
apache_uptime_seconds_totalServer uptime

Useful PromQL queries​

# Request rate/sec
rate(apache_accesses_total[5m])

# Busy vs idle workers
apache_workers{state="busy"}
apache_workers{state="idle"}

# Worker utilisation % (busy / total)
apache_workers{state="busy"}
/ (apache_workers{state="busy"} + apache_workers{state="idle"}) * 100

# Throughput (KB/s)
rate(apache_sent_kilobytes_total[5m])

# CPU load
apache_cpuload

Troubleshooting​

apache_up 0

  • Check mod_status is enabled: apachectl -M | grep status
  • Confirm the server-status location is accessible: curl http://localhost/server-status?auto
  • Ensure Require local allows connections from the exporter's IP

All workers appear busy

  • Check apache_scoreboard for workers in closing or logging state — may indicate slow clients
  • Review MaxRequestWorkers / ServerLimit in your Apache config