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-module(mongoose_instrument_prometheus). |
| 2 |
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| 3 |
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-behaviour(mongoose_instrument). |
| 4 |
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| 5 |
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-export([set_up/3, handle_event/4]). |
| 6 |
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| 7 |
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-spec set_up(mongoose_instrument:event_name(), mongoose_instrument:labels(), |
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mongoose_instrument:config()) -> boolean(). |
| 9 |
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set_up(EventName, Labels, #{metrics := Metrics}) -> |
| 10 |
:-( |
LabelKeys = labels_to_keys(Labels), |
| 11 |
:-( |
maps:foreach(fun(MetricName, MetricType) -> |
| 12 |
:-( |
set_up_metric(EventName, LabelKeys, MetricName, MetricType) |
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end, Metrics), |
| 14 |
:-( |
true; |
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set_up(_EventName, _Labels, #{}) -> |
| 16 |
:-( |
false. |
| 17 |
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| 18 |
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-spec handle_event(mongoose_instrument:event_name(), mongoose_instrument:labels(), |
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mongoose_instrument:config(), mongoose_instrument:measurements()) -> ok. |
| 20 |
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handle_event(EventName, Labels, #{metrics := Metrics}, Measurements) -> |
| 21 |
:-( |
LabelValues = labels_to_values(Labels), |
| 22 |
:-( |
maps:foreach(fun(MetricName, MetricType) -> |
| 23 |
:-( |
handle_metric_event(EventName, LabelValues, MetricName, MetricType, Measurements) |
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end, Metrics). |
| 25 |
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| 26 |
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set_up_metric(EventName, LabelKeys, MetricName, MetricType) -> |
| 27 |
:-( |
MetricSpec = metric_spec(EventName, LabelKeys, MetricName), |
| 28 |
:-( |
declare_metric(MetricSpec, MetricType). |
| 29 |
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declare_metric(MetricSpec, spiral) -> |
| 31 |
:-( |
prometheus_counter:declare(MetricSpec); |
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declare_metric(MetricSpec, histogram) -> |
| 33 |
:-( |
prometheus_histogram:declare([{buckets, histogram_buckets()} | MetricSpec]). |
| 34 |
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metric_spec(EventName, LabelKeys, MetricName) -> |
| 36 |
:-( |
[{name, full_metric_name(EventName, MetricName)}, |
| 37 |
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{help, metric_help(EventName, MetricName)}, |
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{labels, LabelKeys}]. |
| 39 |
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| 40 |
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histogram_buckets() -> |
| 41 |
:-( |
histogram_buckets([], 1 bsl 30). % ~1.07 * 10^9 |
| 42 |
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histogram_buckets(AccBuckets, Val) when Val > 0 -> |
| 44 |
:-( |
histogram_buckets([Val | AccBuckets], Val bsr 1); |
| 45 |
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histogram_buckets(AccBuckets, _Val) -> |
| 46 |
:-( |
AccBuckets. |
| 47 |
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| 48 |
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handle_metric_event(EventName, LabelValues, MetricName, MetricType, Measurements) -> |
| 49 |
:-( |
case Measurements of |
| 50 |
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#{MetricName := MetricValue} -> |
| 51 |
:-( |
FullName = full_metric_name(EventName, MetricName), |
| 52 |
:-( |
update_metric(FullName, LabelValues, MetricType, MetricValue); |
| 53 |
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#{} -> |
| 54 |
:-( |
ok |
| 55 |
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end. |
| 56 |
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| 57 |
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metric_help(EventName, MetricName) -> |
| 58 |
:-( |
lists:flatten(io_lib:format("Event: ~p, Metric: ~p", [EventName, MetricName])). |
| 59 |
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| 60 |
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full_metric_name(EventName, MetricName) -> |
| 61 |
:-( |
list_to_atom(atom_to_list(EventName) ++ "_" ++ atom_to_list(MetricName)). |
| 62 |
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| 63 |
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labels_to_keys(Labels) -> |
| 64 |
:-( |
lists:sort(maps:keys(Labels)). |
| 65 |
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labels_to_values(Labels) -> |
| 67 |
:-( |
[V || {_K, V} <- lists:keysort(1, maps:to_list(Labels))]. |
| 68 |
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| 69 |
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update_metric(Name, Labels, spiral, Value) when is_integer(Value), Value >= 0 -> |
| 70 |
:-( |
prometheus_counter:inc(Name, Labels, Value); |
| 71 |
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update_metric(Name, Labels, histogram, Value) when is_integer(Value) -> |
| 72 |
:-( |
prometheus_histogram:observe(Name, Labels, Value). |