StatsD Tagged Metrics

The tagged metrics observer emits StatsD-compatible time-series metrics about the performance of your application with tags in the InfluxStatsD format. The tags added to the metrics are configurable: any tags that pass through the span.set_tag() function are filtered through a user-supplied whitelist in the configuration file.


Make sure your service calls configure_observers() during application startup and then add the following to your configuration file to enable and configure the StatsD tagged metrics observer.

Do not include a metrics.namespace parameter in the configuration file, as it incompatible with the service.



# required to enable observer
metrics.tagging = true

# optional: whitelist of tags to allow predefined tags from baseplate separated by commas
# defaults to [ endpoint, success, error ] if no value is provided
metrics.whitelist = endpoint, success, error

# optional: the percent of statsd metrics to sample
# if not specified, it will default to 100% (all metrics sent)
# config must be passed to the `Baseplate` constructor to use this option
metrics_observer.sample_rate = 100%


Whitelist Options

Wavefront supports a maximum of 20 tags per cluster and 1000 distinct time series per metric. Baseplate integrations of frameworks come out of the box with some default tags set via span.set_tag(), but to append them to the metrics they must be present in the configuration file via metrics.whitelist.

In order to find these tags to put in the whitelist, look through the code base for calls to span.set_tag() or check a zipkin trace in Wavefront to see all the tags on a span.


For each span in the application, the metrics observer emits a Timer tracking how long the span took and increments a Counter for success or failure of the span (failure being an unexpected exception).

A key differentiation from the untagged StatsD metrics observer is that the emitted outputs from baseplate no longer contain a namespace prefix. Prepending the namespace must be configured in Telegraf via the name_prefix input plugin configuration.

For the ServerSpan representing the request the server is handling, the timer has a name like baseplate.server,endpoint={route_or_method_name} and the counter looks like baseplate.server,success={true,false},endpoint={route_or_method_name}. If the request timed out an additional tag will be added to make it baseplate.server,success={true,false},endpoint={route_or_method_name},timed_out={true,false} assuming that success, endpoint, and timed_out are all present in the whitelist.

For each span representing a call to a remote service or database, the timer has a name like baseplate.clients,endpoint={method} and the counter baseplate.clients,endpoint={method},success={true,false}.

When using baseplate-serve, various process-level runtime metrics will also be emitted. These are not tied to individual requests but instead give insight into how the whole application is functioning. See Process-level metrics for more information.

Direct Use

When enabled, the metrics observer also adds a Client object as an attribute named metrics to the RequestContext which can take an optional tags parameter in the form of a dict:

def my_handler(request):
    request.metrics.counter("foo", {"bar": "baz"}).increment()

To keep your application more generic, it’s better to use local spans for custom local timers and incr_tag() for custom counters.