ece785ff92
Use this middleware and its helpers to accumulate custom New Relic metrics on a per-request basis. If, while handling a request, the app does not accumulate any metrics, this middleware is a very lightweight no-op. This commit also enables the middleware! PERF-354
63 lines
1.9 KiB
Python
63 lines
1.9 KiB
Python
"""
|
|
Middleware for handling the storage, aggregation, and reporing of custom New
|
|
Relic metrics.
|
|
|
|
This middleware will only call on the newrelic agent if there are any metrics
|
|
to report for this request, so it will not incur any processing overhead for
|
|
request handlers which do not record custom metrics.
|
|
"""
|
|
import newrelic.agent
|
|
import request_cache
|
|
|
|
REQUEST_CACHE_KEY = 'newrelic_custom_metrics'
|
|
|
|
|
|
class NewRelicCustomMetrics(object):
|
|
"""
|
|
The middleware class. Make sure to add below the request cache in
|
|
MIDDLEWARE_CLASSES.
|
|
"""
|
|
|
|
@classmethod
|
|
def _get_metrics_cache(cls):
|
|
"""
|
|
Get a reference to the part of the request cache wherein we store New
|
|
Relic custom metrics related to the current request.
|
|
"""
|
|
return request_cache.get_cache(name=REQUEST_CACHE_KEY)
|
|
|
|
@classmethod
|
|
def accumulate_metric(cls, name, value):
|
|
"""
|
|
Accumulate a custom metric (name and value) in the metrics cache.
|
|
"""
|
|
metrics_cache = cls._get_metrics_cache()
|
|
metrics_cache.setdefault(name, 0)
|
|
metrics_cache[name] += value
|
|
|
|
@classmethod
|
|
def _batch_report(cls):
|
|
"""
|
|
Report the collected custom metrics to New Relic.
|
|
"""
|
|
metrics_cache = cls._get_metrics_cache()
|
|
for metric_name, metric_value in metrics_cache.iteritems():
|
|
newrelic.agent.add_custom_parameter(metric_name, metric_value)
|
|
|
|
# Whether or not there was an exception, report any custom NR metrics that
|
|
# may have been collected.
|
|
|
|
def process_response(self, request, response): # pylint: disable=unused-argument
|
|
"""
|
|
Django middleware handler to process a response
|
|
"""
|
|
self._batch_report()
|
|
return response
|
|
|
|
def process_exception(self, request, exception): # pylint: disable=unused-argument
|
|
"""
|
|
Django middleware handler to process an exception
|
|
"""
|
|
self._batch_report()
|
|
return None
|