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Merged
csmarchbanks merged 1 commit into from
Nov 26, 2025
+94 −27
Merged

Don't interleave histogram metrics in multi-process collector #1148

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51 changes: 32 additions & 19 deletions prometheus_client/multiprocess.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -88,32 +88,42 @@ def _parse_key(key):
@staticmethod
def _accumulate_metrics(metrics, accumulate):
for metric in metrics.values():
samples = defaultdict(float)
sample_timestamps = defaultdict(float)
samples = defaultdict(lambda: defaultdict(float))
sample_timestamps = defaultdict(lambda: defaultdict(float))
buckets = defaultdict(lambda: defaultdict(float))
samples_setdefault = samples.setdefault
for s in metric.samples:
name, labels, value, timestamp, exemplar, native_histogram_value = s

if (
metric.type == 'gauge'
and metric._multiprocess_mode in (
'min', 'livemin',
'max', 'livemax',
'sum', 'livesum',
'mostrecent', 'livemostrecent',
)
):
labels = tuple(l for l in labels if l[0] != 'pid')

if metric.type == 'gauge':
without_pid_key = (name, tuple(l for l in labels if l[0] != 'pid'))
if metric._multiprocess_mode in ('min', 'livemin'):
current = samples_setdefault(without_pid_key, value)
current = samples[labels].setdefault((name, labels), value)
if value < current:
samples[without_pid_key] = value
samples[labels][(name, labels)] = value
elif metric._multiprocess_mode in ('max', 'livemax'):
current = samples_setdefault(without_pid_key, value)
current = samples[labels].setdefault((name, labels), value)
if value > current:
samples[without_pid_key] = value
samples[labels][(name, labels)] = value
elif metric._multiprocess_mode in ('sum', 'livesum'):
samples[without_pid_key] += value
samples[labels][(name, labels)] += value
elif metric._multiprocess_mode in ('mostrecent', 'livemostrecent'):
current_timestamp = sample_timestamps[without_pid_key]
current_timestamp = sample_timestamps[labels][name]
timestamp = float(timestamp or 0)
if current_timestamp < timestamp:
samples[without_pid_key] = value
sample_timestamps[without_pid_key] = timestamp
samples[labels][(name, labels)] = value
sample_timestamps[labels][name] = timestamp
else: # all/liveall
samples[(name, labels)] = value
samples[labels][(name, labels)] = value

elif metric.type == 'histogram':
# A for loop with early exit is faster than a genexpr
Expand All @@ -127,10 +137,10 @@ def _accumulate_metrics(metrics, accumulate):
break
else: # did not find the `le` key
# _sum/_count
samples[(name, labels)] += value
samples[labels][(name, labels)] += value
else:
# Counter and Summary.
samples[(name, labels)] += value
samples[labels][(name, labels)] += value

# Accumulate bucket values.
if metric.type == 'histogram':
Expand All @@ -143,14 +153,17 @@ def _accumulate_metrics(metrics, accumulate):
)
if accumulate:
acc += value
samples[sample_key] = acc
samples[labels][sample_key] = acc
else:
samples[sample_key] = value
samples[labels][sample_key] = value
if accumulate:
samples[(metric.name + '_count', labels)] = acc
samples[labels][(metric.name + '_count', labels)] = acc

# Convert to correct sample format.
metric.samples = [Sample(name_, dict(labels), value) for (name_, labels), value in samples.items()]
metric.samples = []
for _, samples_by_labels in samples.items():
for (name_, labels), value in samples_by_labels.items():
metric.samples.append(Sample(name_, dict(labels), value))
return metrics.values()

def collect(self):
Expand Down
70 changes: 62 additions & 8 deletions tests/test_multiprocess.py
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Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -276,10 +276,8 @@ def add_label(key, value):
Sample('g', add_label('pid', '1'), 1.0),
])

metrics['h'].samples.sort(
key=lambda x: (x[0], float(x[1].get('le', 0)))
)
expected_histogram = [
Sample('h_sum', labels, 6.0),
Sample('h_bucket', add_label('le', '0.005'), 0.0),
Sample('h_bucket', add_label('le', '0.01'), 0.0),
Sample('h_bucket', add_label('le', '0.025'), 0.0),
Expand All @@ -296,7 +294,66 @@ def add_label(key, value):
Sample('h_bucket', add_label('le', '10.0'), 2.0),
Sample('h_bucket', add_label('le', '+Inf'), 2.0),
Sample('h_count', labels, 2.0),
Sample('h_sum', labels, 6.0),
]

self.assertEqual(metrics['h'].samples, expected_histogram)

def test_collect_histogram_ordering(self):
pid = 0
values.ValueClass = MultiProcessValue(lambda: pid)
labels = {i: i for i in 'abcd'}

def add_label(key, value):
l = labels.copy()
l[key] = value
return l

h = Histogram('h', 'help', labelnames=['view'], registry=None)

h.labels(view='view1').observe(1)

pid = 1

h.labels(view='view1').observe(5)
h.labels(view='view2').observe(1)

metrics = {m.name: m for m in self.collector.collect()}

expected_histogram = [
Sample('h_sum', {'view': 'view1'}, 6.0),
Sample('h_bucket', {'view': 'view1', 'le': '0.005'}, 0.0),
Sample('h_bucket', {'view': 'view1', 'le': '0.01'}, 0.0),
Sample('h_bucket', {'view': 'view1', 'le': '0.025'}, 0.0),
Sample('h_bucket', {'view': 'view1', 'le': '0.05'}, 0.0),
Sample('h_bucket', {'view': 'view1', 'le': '0.075'}, 0.0),
Sample('h_bucket', {'view': 'view1', 'le': '0.1'}, 0.0),
Sample('h_bucket', {'view': 'view1', 'le': '0.25'}, 0.0),
Sample('h_bucket', {'view': 'view1', 'le': '0.5'}, 0.0),
Sample('h_bucket', {'view': 'view1', 'le': '0.75'}, 0.0),
Sample('h_bucket', {'view': 'view1', 'le': '1.0'}, 1.0),
Sample('h_bucket', {'view': 'view1', 'le': '2.5'}, 1.0),
Sample('h_bucket', {'view': 'view1', 'le': '5.0'}, 2.0),
Sample('h_bucket', {'view': 'view1', 'le': '7.5'}, 2.0),
Sample('h_bucket', {'view': 'view1', 'le': '10.0'}, 2.0),
Sample('h_bucket', {'view': 'view1', 'le': '+Inf'}, 2.0),
Sample('h_count', {'view': 'view1'}, 2.0),
Sample('h_sum', {'view': 'view2'}, 1.0),
Sample('h_bucket', {'view': 'view2', 'le': '0.005'}, 0.0),
Sample('h_bucket', {'view': 'view2', 'le': '0.01'}, 0.0),
Sample('h_bucket', {'view': 'view2', 'le': '0.025'}, 0.0),
Sample('h_bucket', {'view': 'view2', 'le': '0.05'}, 0.0),
Sample('h_bucket', {'view': 'view2', 'le': '0.075'}, 0.0),
Sample('h_bucket', {'view': 'view2', 'le': '0.1'}, 0.0),
Sample('h_bucket', {'view': 'view2', 'le': '0.25'}, 0.0),
Sample('h_bucket', {'view': 'view2', 'le': '0.5'}, 0.0),
Sample('h_bucket', {'view': 'view2', 'le': '0.75'}, 0.0),
Sample('h_bucket', {'view': 'view2', 'le': '1.0'}, 1.0),
Sample('h_bucket', {'view': 'view2', 'le': '2.5'}, 1.0),
Sample('h_bucket', {'view': 'view2', 'le': '5.0'}, 1.0),
Sample('h_bucket', {'view': 'view2', 'le': '7.5'}, 1.0),
Sample('h_bucket', {'view': 'view2', 'le': '10.0'}, 1.0),
Sample('h_bucket', {'view': 'view2', 'le': '+Inf'}, 1.0),
Sample('h_count', {'view': 'view2'}, 1.0),
]

self.assertEqual(metrics['h'].samples, expected_histogram)
Expand Down Expand Up @@ -347,10 +404,8 @@ def add_label(key, value):
m.name: m for m in self.collector.merge(files, accumulate=False)
}

metrics['h'].samples.sort(
key=lambda x: (x[0], float(x[1].get('le', 0)))
)
expected_histogram = [
Sample('h_sum', labels, 6.0),
Sample('h_bucket', add_label('le', '0.005'), 0.0),
Sample('h_bucket', add_label('le', '0.01'), 0.0),
Sample('h_bucket', add_label('le', '0.025'), 0.0),
Expand All @@ -366,7 +421,6 @@ def add_label(key, value):
Sample('h_bucket', add_label('le', '7.5'), 0.0),
Sample('h_bucket', add_label('le', '10.0'), 0.0),
Sample('h_bucket', add_label('le', '+Inf'), 0.0),
Sample('h_sum', labels, 6.0),
]

self.assertEqual(metrics['h'].samples, expected_histogram)
Expand Down