fix: prometheus counters should have _total suffix (#952)

open-telemetry · Jan 29, 2023 · a82d970 · a82d970
1 parent 01564af
commit a82d970
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Showing 2 changed files with 7 additions and 3 deletions.
diff --git a/opentelemetry-prometheus/src/lib.rs b/opentelemetry-prometheus/src/lib.rs
@@ -106,6 +106,10 @@ mod sanitize;
 
 use sanitize::sanitize;
 
+/// Monotonic Sum metric points MUST have _total added as a suffix to the metric name
+/// https://github.com/open-telemetry/opentelemetry-specification/blob/v1.14.0/specification/metrics/data-model.md#sums-1
+const MONOTONIC_COUNTER_SUFFIX: &str = "_total";
+
 /// Create a new prometheus exporter builder.
 pub fn exporter(controller: BasicController) -> ExporterBuilder {
     ExporterBuilder::new(controller)
@@ -329,7 +333,7 @@ fn build_monotonic_counter(
     m.set_counter(c);
 
     let mut mf = prometheus::proto::MetricFamily::default();
-    mf.set_name(desc.name);
+    mf.set_name(desc.name + MONOTONIC_COUNTER_SUFFIX);
     mf.set_help(desc.help);
     mf.set_field_type(prometheus::proto::MetricType::COUNTER);
     mf.set_metric(protobuf::RepeatedField::from_vec(vec![m]));

diff --git a/opentelemetry-prometheus/tests/integration_test.rs b/opentelemetry-prometheus/tests/integration_test.rs
@@ -30,7 +30,7 @@ fn free_unused_instruments() {
         counter.add(&cx, 10.0, &attributes);
         counter.add(&cx, 5.3, &attributes);
 
-        expected.push(r#"counter{A="B",C="D",R="V"} 15.3"#);
+        expected.push(r#"counter_total{A="B",C="D",R="V"} 15.3"#);
     }
     // Standard export
     compare_export(&exporter, expected.clone());
@@ -67,7 +67,7 @@ fn test_add() {
     counter.add(&cx, 10.0, &attributes);
     counter.add(&cx, 5.3, &attributes);
 
-    expected.push(r#"counter{A="B",C="D",R="V"} 15.3"#);
+    expected.push(r#"counter_total{A="B",C="D",R="V"} 15.3"#);
 
     let cb_attributes = attributes.clone();
     let gauge = meter.i64_observable_gauge("intgauge").init();