postfinance / apache-exporter

Exports server statistics provided by mod_status of an Apache HTTP server to Prometheus metrics format

Apache Exporter for Prometheus

Exports server statistics provided by mod_status of an Apache HTTP server to Prometheus metrics format

Usage

It can be built with:

mvn clean install

It can be importer in your Maven project with

<dependency>
  <groupId>com.github.postfinance.prometheus</groupId>
  <artifactId>apache-exporter</artifactId>
  <version>VERSION</version>
</dependency>

ModStatus URL

The Apache ModStatus URL where the metrics are read, can be configured with

• A parameter in the ApacheExporter constructor
• A System Property: httpdModStatusUrl
• An Environment Property: HTTPD_MOD_STATUS_URL

The default value is http://localhost/server-status?auto

Apache HTTPD Metrics

To obtain the metrics for apache, an istance of the ApacheExporter class should be created and one of the following methods called:

• First method

public String export() throws IOException
public String export(String interfaceName) throws IOException

returns a String in the format:

# HELP apache_exporter_build_info A metric with a constant '1' value labeled by version, revision, branch, and goversion from which apache_exporter was built.
# TYPE apache_exporter_build_info gauge
apache_exporter_build_info{branch="HEAD",goversion="go1.12.6",revision="6195241a96c02af175ba2842dfd883682133b066",version="0.7.0"} 1
# HELP apache_scoreboard Apache scoreboard statuses
# TYPE apache_scoreboard gauge
apache_scoreboard{state="closing"} 0
apache_scoreboard{state="dns"} 0
apache_scoreboard{state="graceful_stop"} 0
apache_scoreboard{state="idle"} 6
apache_scoreboard{state="idle_cleanup"} 0
apache_scoreboard{state="keepalive"} 1
apache_scoreboard{state="logging"} 0
apache_scoreboard{state="open_slot"} 142
apache_scoreboard{state="read"} 0
apache_scoreboard{state="reply"} 1
apache_scoreboard{state="startup"} 0
# HELP apache_sent_kilobytes_total Current total kbytes sent (*)
# TYPE apache_sent_kilobytes_total counter
apache_sent_kilobytes_total 5721
# HELP apache_up Could the apache server be reached
# TYPE apache_up gauge
apache_up 1
# HELP apache_uptime_seconds_total Current uptime in seconds (*)
# TYPE apache_uptime_seconds_total counter
apache_uptime_seconds_total 9255
# HELP apache_workers Apache worker statuses
# TYPE apache_workers gauge
apache_workers{state="busy"} 2
apache_workers{state="idle"} 6

Example:

  ApacheExporter exporter = new ApacheExporter("http://myhost:7070/midw-status?auto");
  String result = exporter.export()

• Second method

public ArrayList<Collector.MetricFamilySamples> exportSamplesList()
public ArrayList<Collector.MetricFamilySamples> exportSamplesList(String interfaceName)

It returns a list of samples of type Collector.MetricFamilySamples

Example:

  ApacheExporter exporter = new ApacheExporter("http://myhost:7070/midw-status?auto");
  List<Collector.MetricFamilySamples> mfsList = exporter.exportSamplesList("eth0")

apache-exporter's Issues

Configurable URL to mod_status

The URL for getting the statistic data of mod_status must be configurable. Default is http://localhost/server-status?auto

A different value can be provided by an environment variable and a system property

https://github.com/postfinance/apache_exporter/blob/c6538f4eb32e0fd11f0478c50c618a453084fbd7/src/main/java/ch/postfinance/prometheus/ApacheExporter.java#L139

Add interface selection

Add the possibility to bind a specific interface in the httpclient

Add server functionality

Provide server functionality so that this project can be executed as a standalone server.

• Create a listener (Hostname and Port are configurable)
• Define a scrape interval, this value is configurable