Add Span.add_metric

ddtrace/contrib/elasticsearch/transport.py

@@ -49,8 +49,7 @@ def perform_request(self, method, url, params=None, body=None):
                 _, data = result
                 took = data.get("took")
                 if took:
-                    # TODO: move that to a metric instead
-                    s.set_tag(metadata.TOOK, took)
+                    s.set_metric(metadata.TOOK, int(took))
 
                 return result
 

ddtrace/contrib/psycopg/connection.py

@@ -64,7 +64,7 @@ def execute(self, query, vars=None):
             try:
                 return super(TracedCursor, self).execute(query, vars)
             finally:
-                s.set_tag("db.rowcount", self.rowcount)
+                s.set_metric("db.rowcount", self.rowcount)
 
     def callproc(self, procname, vars=None):
         """ just wrap the execution in a span """

ddtrace/contrib/redis/tracers.py

@@ -63,9 +63,8 @@ def execute(self, *args, **kwargs):
 
                     s.set_tags(_extract_conn_tags(self.connection_pool.connection_kwargs))
                     s.set_tags(self._datadog_meta)
-                    # FIXME[leo]: convert to metric?
-                    s.set_tag(redisx.PIPELINE_LEN, len(self.command_stack))
-                    s.set_tag(redisx.PIPELINE_AGE, time.time()-self._datadog_pipeline_creation)
+                    s.set_metric(redisx.PIPELINE_LEN, len(self.command_stack))
+                    s.set_metric(redisx.PIPELINE_AGE, time.time()-self._datadog_pipeline_creation)
 
                 return super(TracedPipeline, self).execute(self, *args, **kwargs)
 
@@ -84,8 +83,7 @@ def immediate_execute_command(self, *args, **kwargs):
 
                     s.set_tags(_extract_conn_tags(self.connection_pool.connection_kwargs))
                     s.set_tags(self._datadog_meta)
-                    # FIXME[leo]: convert to metric?
-                    s.set_tag(redisx.ARGS_LEN, len(args))
+                    s.set_metric(redisx.ARGS_LEN, len(args))
 
                     s.set_tag(redisx.IMMEDIATE_PIPELINE, True)
 
@@ -113,8 +111,7 @@ def execute_command(self, *args, **options):
 
                     s.set_tags(_extract_conn_tags(self.connection_pool.connection_kwargs))
                     s.set_tags(self._datadog_meta)
-                    # FIXME[leo]: convert to metric?
-                    s.set_tag(redisx.ARGS_LEN, len(args))
+                    s.set_metric(redisx.ARGS_LEN, len(args))
 
                 return super(TracedRedis, self).execute_command(*args, **options)
 

ddtrace/span.py

@@ -1,4 +1,5 @@
 import logging
+import numbers
 import random
 import sys
 import time
@@ -89,7 +90,7 @@ def set_tag(self, key, value):
         try:
             self.meta[key] = stringify(value)
         except Exception:
-            log.warning("error setting tag. ignoring", exc_info=True)
+            log.warning("error setting tag %s, ignoring it", key, exc_info=True)
 
     def get_tag(self, key):
         """ Return the given tag or None if it doesn't exist.
@@ -110,6 +111,18 @@ def set_meta(self, k, v):
     def set_metas(self, kvs):
         self.set_tags(kvs)
 
+    def set_metric(self, key, value):
+        try:
+            # If the value isn't a typed as a number (ex: a string), try to cast it
+            if not isinstance(value, numbers.Number):
+                value = float(value)
+            self.metrics[key] = value
+        except Exception:
+            log.warning("error setting metric %s, ignoring it", key, exc_info=True)
+
+    def get_metric(self, key):
+        return self.metrics.get(key)
+
     def to_dict(self):
         d = {
             'trace_id' : self.trace_id,
@@ -131,6 +144,9 @@ def to_dict(self):
         if self.meta:
             d['meta'] = self.meta
 
+        if self.metrics:
+            d['metrics'] = self.metrics
+
         if self.span_type:
             d['type'] = self.span_type
 

tests/contrib/elasticsearch/test.py

@@ -88,5 +88,4 @@ def test_elasticsearch(self):
         eq_(span.get_tag(metadata.BODY).replace(" ", ""), '{"query":{"match_all":{}}}')
         eq_(set(span.get_tag(metadata.PARAMS).split('&')), {'sort=name%3Adesc', 'size=100'})
 
-        self.assertTrue(int(span.get_tag(metadata.TOOK)) > 0)
-
+        self.assertTrue(span.get_metric(metadata.TOOK) > 0)

tests/contrib/redis/test.py

@@ -45,12 +45,18 @@ def test_basic_class(self):
         eq_(span.name, 'redis.command')
         eq_(span.span_type, 'redis')
         eq_(span.error, 0)
-        eq_(span.meta, {'out.host': u'localhost', 'redis.raw_command': u'GET cheese', 'out.port': u'6379', 'redis.args_length': u'2', 'out.redis_db': u'0'})
+        eq_(span.meta, {
+            'out.host': u'localhost',
+            'redis.raw_command': u'GET cheese',
+            'out.port': u'6379',
+            'out.redis_db': u'0',
+        })
+        eq_(span.get_metric('redis.args_length'), 2)
         eq_(span.resource, 'GET cheese')
 
         services = writer.pop_services()
         expected = {
-            self.SERVICE: {"app":"redis", "app_type":"db"}
+            self.SERVICE: {"app": "redis", "app_type": "db"}
         }
         eq_(services, expected)
 
@@ -88,15 +94,15 @@ def test_basic_class_pipeline(self):
         span = spans[0]
         eq_(span.service, self.SERVICE)
         eq_(span.name, 'redis.pipeline')
+        eq_(span.resource, u'SET blah 32\nRPUSH foo éé\nHGETALL xxx')
         eq_(span.span_type, 'redis')
         eq_(span.error, 0)
         eq_(span.get_tag('out.redis_db'), '0')
         eq_(span.get_tag('out.host'), 'localhost')
-        ok_(float(span.get_tag('redis.pipeline_age')) > 0)
-        eq_(span.get_tag('redis.pipeline_length'), '3')
         eq_(span.get_tag('out.port'), '6379')
-        eq_(span.resource, u'SET blah 32\nRPUSH foo éé\nHGETALL xxx')
         eq_(span.get_tag('redis.raw_command'), u'SET blah 32\nRPUSH foo éé\nHGETALL xxx')
+        ok_(span.get_metric('redis.pipeline_age') > 0)
+        eq_(span.get_metric('redis.pipeline_length'), 3)
 
     def test_custom_class(self):
         class MyCustomRedis(redis.Redis):

tests/test_span.py

@@ -31,6 +31,32 @@ def test_tags():
     }
     eq_(d["meta"], expected)
 
+def test_set_valid_metrics():
+    s = Span(tracer=None, name="foo")
+    s.set_metric("a", 0)
+    s.set_metric("b", -12)
+    s.set_metric("c", 12.134)
+    s.set_metric("d", 1231543543265475686787869123)
+    s.set_metric("e", "12.34")
+    d = s.to_dict()
+    expected = {
+        "a": 0,
+        "b": -12,
+        "c": 12.134,
+        "d": 1231543543265475686787869123,
+        "e": 12.34,
+    }
+    eq_(d["metrics"], expected)
+
+
+def test_set_invalid_metric():
+    s = Span(tracer=None, name="foo")
+
+    # Set an invalid metric: shouldn't crash nor set any value
+    s.set_metric("a", "forty-twelve")
+
+    eq_(s.get_metric("a"), None)
+
 def test_tags_not_string():
     # ensure we can cast as strings
     class Foo(object):