Monitoring HTTP

This article will help you get the Http plugin for sd-agent configured and returning metrics

Installing the http plugin package

Install the http plugin on Debian/Ubuntu:

sudo apt-get install sd-agent-http-check

Install the http plugin on RHEL/CentOS:

sudo yum install sd-agent-http-check

Read more about agent plugins.

Configuring the agent to collect swap metrics

1. Configure /etc/sd-agent/conf.d/http_check.yaml

init_config:

instances:
  - name: Example website
    url: https://example.com/
    # disable_ssl_validation: false      # default is true, so set false to check SSL validation
    # ca_certs: /path/to/ca/file         # e.g. /etc/ssl/certs/ca-certificates.crt
    # check_certificate_expiration: true # default is true
    # timeout: 3                         # in seconds. Default is 1.
  - name: Example website (staging)
    url: http://staging.example.com/

2. Restart the agent

sudo /etc/init.d/sd-agent restart

or

sudo systemctl restart sd-agent

Verifying the configuration
Execute info to verify the configuration with the following:

sudo /etc/init.d/sd-agent info 

or

/usr/share/python/sd-agent/agent.py info

If the agent has been configured correctly you'll see an output such as:

http
-----
  - instance #0 [OK]
  - Collected * metrics

You can also view the metrics returned with the following command:

sudo -u sd-agent /usr/share/python/sd-agent/agent.py check http_check

Configuring graphs

Click the name of your server from the Devices list in your Server Density account then go to the Metrics tab. Click the + Graph button on the right then choose the http metrics to display the graphs. The metrics will also be available to select when building dashboard graphs.

Monitored metrics

Metric	Values
http.ssl.days_left Days until SSL certificate expiration	day / None Type: float
network.http.response_time The response time of an HTTP request to a given url, tagged by url, e.g. 'url:http://example.com'.	second / None Type: float
network.http.can_connect Whether the check can connect, 1 if true, 0 otherwise. Tagged by url, e.g. 'url:http://example.com'.	None / None Type: int
network.http.cant_connect Whether the check failed to connect, 1 if true, 0 otherwise. Tagged by url, e.g. 'url:http://example.com'.	None / None Type: int