Add InfluxDB example.

docs/examples.rst

@@ -16,3 +16,22 @@ as a base class.
 
 .. literalinclude:: ../examples/statsd.py
    :pyobject: SimpleHandler
+
+Sending measurements to InfluxDB
+--------------------------------
+This simple application sends per-request measurements to an InfluxDB
+server listening on ``localhost``.  The mix-in is configured by passing
+a ``sprockets.mixins.metrics.influxdb`` key into the application settings
+as shown below.
+
+.. literalinclude:: ../examples/influxdb.py
+   :pyobject: make_application
+
+The InfluxDB database and measurement name are also configured in the
+application settings object.  The request handler is responsible for
+providing the tag and value portions of the measurement.  The standard
+:class:`Metric Mixin API<sprockets.mixins.metrics.Mixin>` is used to set
+tagged values.
+
+.. literalinclude:: ../examples/influxdb.py
+   :pyobject: SimpleHandler

examples/influxdb.py

@@ -0,0 +1,76 @@
+import os
+import signal
+
+from sprockets.mixins import metrics
+from tornado import gen, ioloop, web
+
+
+class SimpleHandler(metrics.InfluxDBMixin, web.RequestHandler):
+    """
+    Simply emits a few metrics around the GET method.
+
+    The ``InfluxDBMixin`` sends all of the metrics gathered during
+    the processing of a request as a single measurement when the
+    request is finished.  Each request of this sample will result
+    in a single measurement using the service name as the key.
+
+    The following tag keys are defined by default:
+
+        handler="examples.influxdb.SimpleHandler"
+        host="$HOSTNAME"
+        method="GET"
+
+    and the following values are written:
+
+        duration=0.2573668956756592
+        sleepytime=0.255108118057251
+        slept=42
+        status_code=204
+
+    The duration and status_code values are handled by the mix-in
+    and the slept and sleepytime values are added in the method.
+
+    """
+
+    @gen.coroutine
+    def get(self):
+        with self.execution_timer('sleepytime'):
+            yield gen.sleep(0.25)
+            self.increase_counter('slept', amount=42)
+        self.set_status(204)
+        self.finish()
+
+
+def _sig_handler(*args_):
+    iol = ioloop.IOLoop.instance()
+    iol.add_callback_from_signal(iol.stop)
+
+
+def make_application():
+    """
+    Create a application configured to send metrics.
+
+    Measurements will be sent to the ``testing`` database on the
+    configured InfluxDB instance.  The measurement name is set
+    by the ``service`` setting.
+
+    """
+    influx_url = 'http://{}:{}/write'.format(
+        os.environ.get('INFLUX_HOST', '127.0.0.1'),
+        os.environ.get('INFLUX_PORT', 8086))
+    settings = {
+        metrics.InfluxDBMixin.SETTINGS_KEY: {
+            'measurement': 'cli',
+            'database': 'testing',
+            'write_url': influx_url,
+        }
+    }
+    return web.Application([web.url('/', SimpleHandler)], **settings)
+
+
+if __name__ == '__main__':
+    app = make_application()
+    app.listen(8000)
+    signal.signal(signal.SIGINT, _sig_handler)
+    signal.signal(signal.SIGTERM, _sig_handler)
+    ioloop.IOLoop.instance().start()