Plugin cURL JSON Cherokee

This page contains some example configurations for the cURL-JSON plugin. This page is meant as a cookbook, so if you have a configuration for an aspect not handled here or a daemon not present, please feel free to add anything that's useful for you.

Cherokee webserver

The Cherokee webserver exposes its statistics as JSON format which make easy to grab the values with collectd using the cURL-JSON plugin. This chapter will explain how to get information about traffic and connections from Cherokee. This is an extract of a small article I wrote on my website.

In my case I just monitor a limited set of values (traffic, numbers of connections and I/O cache), but there are a lot of information provided by this handler. <hint>Feel free to expand the config below!</hint>

In Cherokee, you need to enable the statistics interface. For that you'll need to activate the server info handler in a web directory; as this is beyond the scope of this example I suggest you to have a look at the documentation

Add the following configuration to your collectd.conf.

 # collectd.conf
 LoadPlugin "curl_json"
 …
 <Plugin "curl_json">
   <nowiki><URL "http://localhost/about/info/js"></nowiki>
    Instance "cherokee"

    <Key "traffic/tx">
      Type "httpd_bytes"
    </Key>

    <Key "traffic/rx">
      Type "httpd_bytes"
    </Key>

    <Key "connections/number">
      Type "httpd_connections"
    </Key>

    <Key "iocache/hits">
      Type "percent"
    </Key>
   </URL>
 </Plugin>

URL defines the URL used to retrieve the JSON data, so it is likely to change for you.

You'll need to create a custom types.db(5) and add these types:

 # types.db
 httpd_bytes             count:COUNTER:0:134217728
 httpd_connections       count:GAUGE:0:65535
 httpd_requests          count:COUNTER:0:134217728

Finally add the new types.db to the collectd configuration. Since this overrides the default, you need to explicitly configure the default types.db, too:

 # collectd.conf
 TypesDB "/usr/share/collectd/types.db"
 TypesDB "/etc/collectd/types.db.custom"

References

• Cheroke Webserver http://www.cherokee-project.com/
• Cherokee Server Info Handler http://www.cherokee-project.com/doc/modules_handlers_server_info.html