prometheus · ratanboddu · May 22, 2019
diff --git a/prometheus_client/metrics.py b/prometheus_client/metrics.py
@@ -412,12 +412,15 @@ def _metric_init(self):
        self._count = values.ValueClass(self._type, self._name, self._name + '_count', self._labelnames,
                                        self._labelvalues)
        self._sum = values.ValueClass(self._type, self._name, self._name + '_sum', self._labelnames, self._labelvalues)
+        self._delta = 0.0
        self._created = time.time()

+
    def observe(self, amount):
        """Observe the given amount."""
        self._count.inc(1)
        self._sum.inc(amount)
+        self._delta = amount

    def time(self):
        """Time a block of code or function, and observe the duration in seconds.
@@ -430,7 +433,8 @@ def _child_samples(self):
        return (
            ('_count', {}, self._count.get()),
            ('_sum', {}, self._sum.get()),
-            ('_created', {}, self._created))
+            ('_created', {}, self._created),
+            ('_delta', {}, self._delta))


 class Histogram(MetricWrapperBase):
@@ -511,6 +515,7 @@ def _prepare_buckets(self, buckets):
    def _metric_init(self):
        self._buckets = []
        self._created = time.time()
+        self._delta = 0.0
        bucket_labelnames = self._labelnames + ('le',)
        self._sum = values.ValueClass(self._type, self._name, self._name + '_sum', self._labelnames, self._labelvalues)
        for b in self._upper_bounds:
@@ -525,6 +530,7 @@ def _metric_init(self):
    def observe(self, amount):
        """Observe the given amount."""
        self._sum.inc(amount)
+        self._delta = amount
        for i, bound in enumerate(self._upper_bounds):
            if amount <= bound:
                self._buckets[i].inc(1)
@@ -546,6 +552,8 @@ def _child_samples(self):
        samples.append(('_count', {}, acc))
        samples.append(('_sum', {}, self._sum.get()))
        samples.append(('_created', {}, self._created))
+        samples.append(('_delta', {}, self._delta))
+
        return tuple(samples)



diff --git a/tests/openmetrics/test_exposition.py b/tests/openmetrics/test_exposition.py
@@ -61,6 +61,7 @@ def test_summary(self):
 ss_count{a="c",b="d"} 1.0
 ss_sum{a="c",b="d"} 17.0
 ss_created{a="c",b="d"} 123.456
+ss_delta{a="c",b="d"} 17.0
 # EOF
 """, generate_latest(self.registry))

@@ -88,6 +89,7 @@ def test_histogram(self):
 hh_count 1.0
 hh_sum 0.05
 hh_created 123.456
+hh_delta 0.05
 # EOF
 """, generate_latest(self.registry))


diff --git a/tests/test_exposition.py b/tests/test_exposition.py
@@ -82,6 +82,7 @@ def test_summary(self):
 # TYPE ss summary
 ss_count{a="c",b="d"} 1.0
 ss_sum{a="c",b="d"} 17.0
+ss_delta{a="c",b="d"} 17.0
 # TYPE ss_created gauge
 ss_created{a="c",b="d"} 123.456
 """, generate_latest(self.registry))
@@ -109,6 +110,7 @@ def test_histogram(self):
 hh_bucket{le="+Inf"} 1.0
 hh_count 1.0
 hh_sum 0.05
+hh_delta 0.05
 # TYPE hh_created gauge
 hh_created 123.456
 """, generate_latest(self.registry))