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Apache HTTP

Auto-Detection
Health Check
Built-in Metrics
Logs
Tutorial available Monitoring Apache Web Server with Bleemeo
Read the tutorial

Apache HTTP Server is the most widely deployed open-source web server.

Auto-Detection

Section titled “Auto-Detection”

Glouton detects Apache by its process and listening port (default: 80).

To enable metrics gathering, ensure Glouton can access the Apache status page at http://server-address/server-status?auto. This is enabled by default on Ubuntu and Debian. If not, add the following to your default virtual host (e.g. the first file in /etc/apache2/sites-enabled/):

LoadModule status_module /usr/lib/apache2/modules/mod_status.so


<Location /server-status>
    SetHandler server-status
    # You may want to limit access only to Bleemeo agent
    # require ip IP-OF-BLEEMEO-AGENT/32
</Location>
ExtendedStatus On

When using Docker, you can set http_path and http_host via labels:

docker run --label glouton.http_path="/readiness" --label glouton.http_host="my-host" [...]

If auto-detected parameters are incorrect, override them manually:

Terminal window
sudo tee /etc/glouton/conf.d/99-apache.conf > /dev/null << 'EOF'
service:
  # For an Apache running outside a container
  - type: "apache"
    address: "127.0.0.1"
    port: 80   # HTTP listener, agent does not support HTTPS here
    http_path: "/"   # Path used for availability check, not metrics gathering
    http_host: "127.0.0.1:80"   # Host header sent


  # For an additional Apache running outside a container
  - type: "apache"
    instance: "NAME_ASSOCIATED_WITH_YOUR_ADDITIONAL_SERVICE"
    address: "127.0.0.1"
    port: 81
    http_path: "/"
    http_host: "127.0.0.1:80"


  # For an Apache running in a Docker container
  - type: "apache"
    instance: "CONTAINER_NAME"
    address: "172.17.0.2"
    port: 80
    http_path: "/"
    http_host: "127.0.0.1:80"
EOF

Glouton automatically detects configuration changes.

Health Check

Section titled “Health Check”

Glouton performs an HTTP check on the configured port and path to verify that Apache is responding.

Built-in Metrics

Section titled “Built-in Metrics”
Metric Description
service_status Status of Apache
apache_busy_workers Number of busy Apache workers
apache_busy_workers_perc Percentage of busy Apache workers
apache_bytes Network traffic sent by Apache in bytes per second
apache_connections Number of client connections to the Apache server
apache_idle_workers Number of Apache workers waiting for an incoming request
apache_max_workers Maximum number of configured Apache workers
apache_requests Number of requests per second
apache_uptime Time since Apache server start in seconds

Apache tracks server activity in a structure called the scoreboard. Each worker has a slot that holds its current status. The scoreboard size equals the maximum number of concurrent clients Apache can serve.

Metric Description
apache_scoreboard_waiting Number of workers waiting for an incoming request (same as apache_idle_workers)
apache_scoreboard_starting Number of workers starting up
apache_scoreboard_reading Number of workers reading an incoming request
apache_scoreboard_sending Number of workers processing a client request
apache_scoreboard_keepalive Number of workers waiting for another request via keepalive
apache_scoreboard_dnslookup Number of workers looking up a hostname
apache_scoreboard_closing Number of workers closing their connection
apache_scoreboard_logging Number of workers writing to log files
apache_scoreboard_finishing Number of workers gracefully finishing a request
apache_scoreboard_idle_cleanup Number of idle workers being killed
apache_scoreboard_open Number of empty slots with no worker in the scoreboard

Apache does not start all workers when they are not needed — it reuses idle workers instead. The sum of all scoreboard items equals the maximum concurrent requests Apache can serve, stored in the apache_max_workers metric.

Logs

Section titled “Logs”

Glouton collects Apache HTTP access and error logs for analysis in Bleemeo.