instrumentation.md

Instrumentation

Bjoern can export connection and request metrics to statsd. If you want support for instrumentation you must compile bjoern manually with

BJOERN_WANT_STATSD=yes python setup.py install
# or
WANT_STATSD=yes make all

you can also enable Dogstatsd tags support by compiling with

BJOERN_WANT_STATSD=yes BJOERN_WANT_STATSD_TAGS=yes python setup.py install
# or
WANT_STATSD=yes WANT_STATSD_TAGS=yes make all

After building with statsd support you can enable statsd metrics on server boot by setting enable_statsd=True, e.g.

bjoern.listen(wsgi_application, host, port)
bjoern.run(statsd={'enable': True, 'host': '...', port: ..., ns: 'bjoern'})

# With tags
# Note that the tags parameter takes a comma separated string of tags, not a list of strings.
bjoern.run(statsd={'enable': True, 'host': '...', port: ..., ns: 'bjoern', 'tags': 'app:my-app-name,zone:central-europe'})

Following metrics are exposed:

Name	Type	Description
conn.accept.error	increment	Incremented if bjoern fails to accept the socket connection from client
conn.accept.success	increment	Incremented when a socket connection is accepted successfully
req.error.client_disconnected	increment	Incremented if client disconnects before bjoern could read request
req.error.read	increment	Incremented if bjoern fails to read request data from a valid connection
req.error.parse	increment	Incremented if bjoern fails to parse the content as valid HTTP request
req.success.read	increment	Incremented every time a request is read and parsed successfully
req.error.internal	increment	Incremented if bjoern fails to successfully call the WSGI application
req.active	increment	Incremented when a request is accepted as a valid one and bjoern is expecting more data from client
req.done	increment	Incremented when a request is read and parsed completely and no more data is expected from client, server is expected to send response now
req.aborted	increment	Incremented if the request is aborted before it was read or parsed completely. At the moment this is same as req.error.read but logically these are two different things and will diverge in future
resp.active	increment	Incremented when bjoern is sending response and
resp.done	increment	Incremented when bjoern is done sending the response
resp.done.keepalive	increment	Incremented when the response is sent but the connection is kept alive
resp.conn.close	increment	Incremented when the response is sent and connection is closed
resp.aborted	increment	Incremented when there is an error in sending response. At this point the connection is also closed