Metrics: Replace redundant metrics by aliases

src/pretix/base/metrics.py

@@ -1,4 +1,5 @@
 import math
+from collections import defaultdict
 
 from django.apps import apps
 from django.conf import settings
@@ -186,20 +187,28 @@ class Histogram(Metric):
 
 def metric_values():
     """
-    Produces the scrapable textformat to be presented to the monitoring system
+    Produces the the values to be presented to the monitoring system
     """
-    metrics = {}
+    metrics = defaultdict(dict)
 
     # Metrics from redis
     if settings.HAS_REDIS:
         for key, value in redis.hscan_iter(REDIS_KEY):
             dkey = key.decode("utf-8")
+            splitted = dkey.split("{", 2)
             value = float(value.decode("utf-8"))
-            metrics[dkey] = value
+            metrics[splitted[0]]["{" + splitted[1]] = value
+
+    # Aliases
+    aliases = {
+        'pretix_view_requests_total': 'pretix_view_duration_seconds_count'
+    }
+    for a, atarget in aliases.items():
+        metrics[a] = metrics[atarget]
 
     # Throwaway metrics
     for m in apps.get_models():  # Count all models
-        metrics['pretix_model_instances{model="%s"}' % m._meta] = m.objects.count()
+        metrics['pretix_model_instances']['{model="%s"}' % m._meta] = m.objects.count()
 
     return metrics
 
@@ -207,8 +216,6 @@ def metric_values():
 """
 Provided metrics
 """
-pretix_view_requests_total = Counter("pretix_view_requests_total", "Total number of HTTP requests made.",
-                                     ["status_code", "method", "url_name"])
 pretix_view_duration_seconds = Histogram("pretix_view_duration_seconds", "Return time of views.",
                                          ["status_code", "method", "url_name"])
 pretix_task_runs_total = Counter("pretix_task_runs_total", "Total calls to a celery task",

src/pretix/base/views/metrics.py

@@ -38,8 +38,9 @@ def serve_metrics(request):
     m = metrics.metric_values()
 
     output = []
-    for metric, value in m.items():
+    for metric, sub in m.items():
-        output.append("{} {}".format(metric, str(value)))
+        for label, value in sub.items():
+            output.append("{}{} {}".format(metric, label, str(value)))
 
     content = "\n".join(output) + "\n"
 

src/pretix/helpers/metrics/middleware.py

@@ -2,9 +2,7 @@ import time
 
 from django.urls import resolve
 
-from pretix.base.metrics import (
+from pretix.base.metrics import pretix_view_duration_seconds
-    pretix_view_duration_seconds, pretix_view_requests_total,
-)
 
 
 class MetricsMiddleware(object):
@@ -30,8 +28,6 @@ class MetricsMiddleware(object):
         t0 = time.perf_counter()
         resp = self.get_response(request)
         tdiff = time.perf_counter() - t0
-        pretix_view_requests_total.inc(1, status_code=resp.status_code, method=request.method,
-                                       url_name=url.namespace + ':' + url.url_name)
         pretix_view_duration_seconds.observe(tdiff, status_code=resp.status_code, method=request.method,
                                              url_name=url.namespace + ':' + url.url_name)
 

src/tests/base/test_metrics.py

@@ -34,29 +34,31 @@ def test_counter(monkeypatch):
     fake_redis = FakeRedis()
 
     monkeypatch.setattr(metrics, "redis", fake_redis, raising=False)
+    pretix_view_requests_total = metrics.Counter("pretix_view_requests_total", "Total number of HTTP requests made.",
+                                                 ["status_code", "method", "url_name"])
 
     # now test
-    fullname_get = metrics.pretix_view_requests_total._construct_metric_identifier(
+    fullname_get = pretix_view_requests_total._construct_metric_identifier(
         'pretix_view_requests_total', {"status_code": "200", "url_name": "foo", "method": "GET"}
     )
-    fullname_post = metrics.pretix_view_requests_total._construct_metric_identifier(
+    fullname_post = pretix_view_requests_total._construct_metric_identifier(
         'pretix_view_requests_total', {"status_code": "200", "url_name": "foo", "method": "POST"}
     )
-    metrics.pretix_view_requests_total.inc(status_code="200", url_name="foo", method="GET")
+    pretix_view_requests_total.inc(status_code="200", url_name="foo", method="GET")
     assert fake_redis.storage[fullname_get] == 1
-    metrics.pretix_view_requests_total.inc(status_code="200", url_name="foo", method="GET")
+    pretix_view_requests_total.inc(status_code="200", url_name="foo", method="GET")
     assert fake_redis.storage[fullname_get] == 2
-    metrics.pretix_view_requests_total.inc(7, status_code="200", url_name="foo", method="GET")
+    pretix_view_requests_total.inc(7, status_code="200", url_name="foo", method="GET")
     assert fake_redis.storage[fullname_get] == 9
-    metrics.pretix_view_requests_total.inc(7, status_code="200", url_name="foo", method="POST")
+    pretix_view_requests_total.inc(7, status_code="200", url_name="foo", method="POST")
     assert fake_redis.storage[fullname_get] == 9
     assert fake_redis.storage[fullname_post] == 7
 
     with pytest.raises(ValueError):
-        metrics.pretix_view_requests_total.inc(-4, status_code="200", url_name="foo", method="POST")
+        pretix_view_requests_total.inc(-4, status_code="200", url_name="foo", method="POST")
 
     with pytest.raises(ValueError):
-        metrics.pretix_view_requests_total.inc(-4, status_code="200", url_name="foo", method="POST", too="much")
+        pretix_view_requests_total.inc(-4, status_code="200", url_name="foo", method="POST", too="much")
 
     # test dimensionless counters
     dimless_counter = metrics.Counter("dimless_counter", "this is a helpstring")
@@ -166,11 +168,13 @@ def test_metrics_view(monkeypatch, client):
     monkeypatch.setattr(metricsview.metrics, "redis", fake_redis, raising=False)
 
     counter_value = 3
-    fullname = metrics.pretix_view_requests_total._construct_metric_identifier(
+    pretix_view_requests_total = metrics.Counter("pretix_view_requests_total", "Total number of HTTP requests made.",
+                                                 ["status_code", "method", "url_name"])
+    fullname = pretix_view_requests_total._construct_metric_identifier(
         'http_requests_total',
         {"status_code": "200", "url_name": "foo", "method": "GET"}
     )
-    metricsview.metrics.pretix_view_requests_total.inc(counter_value, status_code="200", url_name="foo", method="GET")
+    pretix_view_requests_total.inc(counter_value, status_code="200", url_name="foo", method="GET")
 
     # test unauthorized-page
     assert "You are not authorized" in client.get('/metrics').content.decode('utf-8')