Write HTTP plug-in

The Write HTTP plug-in of SSC Serv allows you to send metrics to a web service. Metrics are encoded in JSON and sent via POST requests.

Configuration

Main window of SSC Serv's Write HTTP plug-in configuration: You can add, edit and remove Web servers using the appropriate buttons below the list of servers.

Dialog box for adding or editing a single Web server. If you have worked with collectd's Write HTTP plug-in before, you should feel right at home. You can specify the following settings:

URL: The HTTP or HTTPS address to which POST requests are sent.
Username: If specified, this username is used for HTTP basic authentication. Otherwise no authentication is provided to the server.
Password: If specified, this password is used for HTTP basic authentication. Otherwise, if Username is non-empty, an empty password is used to authenticate.
Store rates: Controls how values are sent to the web server.
If enabled, the default, counters are converted to a rate before being POSTed. The ds_types array will still list “derive” for converted rates.
If disabled, counters are forwarded to the web server as-is and will have to be converted to a rate by another mean before creating meaningful graphs.

Data format

The JSON structure emitted by this plug-in is identical to the JSON schema used by collectd's Write HTTP plugin. An example metric is printed below.

[
  {
    "values": [70.8, 0],
    "dstypes": ["derive", "derive"],
    "dsnames": ["rx", "tx"],
    "time": 1387438858.000,
    "interval": 10.000,
    "host": "dido.octo.it",
    "plugin": "interface",
    "plugin_instance": "Sitecom 300N Wireless USB Adapter WL-352v3",
    "type": "if_packets",
    "type_instance": ""
  },
  ...
]

Registry

The Write HTTP plug-in stores its configuration in the Windows Registry under the HKEY_LOCAL_MACHINE\SOFTWARE\octo\SSC Serv\Write_HTTP key. Each server is configured under its own subkey. The name of the subkey is not relevant, by default the configuration utility will use a GUID, for example {e8aa71c2-6a5c-11e3-a2ef-0019d10dfc65}. Each subkey can have the following values which directly correspond to the options listed above:

HKEY_LOCAL_MACHINE\SOFTWARE\octo\SSC Serv\
  Write_HTTP\
    {e8aa71c2-6a5c-11e3-a2ef-0019d10dfc65}\
      URL                "https://api.example.com/put"
      Username           "myuser"
      Password           "mypassword"
      StoreRates         "true"

SSC Serv