fix: add explicit histogram boundaries to metrics

This commit introduces predefined boundary constants for histograms and applies them in several test cases within the Prometheus exporter integration test. It eliminates the use of the experimental metrics view feature by removing its configuration from the SdkMeterProvider setup and the dependencies.

Change taken from @ttys3, thanks :)

Co-authored-by: ttys3 <[email protected]>

Author: kudlatyamroth

opentelemetry-prometheus/Cargo.toml

@@ -22,7 +22,7 @@ rustdoc-args = ["--cfg", "docsrs"]
 [dependencies]
 once_cell = { workspace = true }
 opentelemetry = { version = "0.27", default-features = false, features = ["metrics"] }
-opentelemetry_sdk = { version = "0.27", default-features = false, features = ["metrics", "spec_unstable_metrics_views"] }
+opentelemetry_sdk = { version = "0.27", default-features = false, features = ["metrics"] }
 prometheus = "0.13"
 protobuf = "2.14"
 tracing = {workspace = true, optional = true} # optional for opentelemetry internal logging

opentelemetry-prometheus/tests/integration_test.rs

@@ -7,14 +7,23 @@ use opentelemetry::metrics::{Meter, MeterProvider as _};
 use opentelemetry::KeyValue;
 use opentelemetry::{InstrumentationScope, Key};
 use opentelemetry_prometheus::{ExporterBuilder, ResourceSelector};
-use opentelemetry_sdk::metrics::{new_view, Aggregation, Instrument, SdkMeterProvider, Stream};
+use opentelemetry_sdk::metrics::SdkMeterProvider;
 use opentelemetry_sdk::resource::{
     EnvResourceDetector, SdkProvidedResourceDetector, TelemetryResourceDetector,
 };
 use opentelemetry_sdk::Resource;
 use opentelemetry_semantic_conventions::resource::{SERVICE_NAME, TELEMETRY_SDK_VERSION};
 use prometheus::{Encoder, TextEncoder};
 
+const BOUNDARIES: &[f64] = &[
+    0.0, 5.0, 10.0, 25.0, 50.0, 75.0, 100.0, 250.0, 500.0, 1000.0,
+];
+
+const BYTES_BOUNDARIES: &[f64] = &[
+    0.0, 5.0, 10.0, 25.0, 50.0, 75.0, 100.0, 250.0, 500.0, 750.0, 1000.0, 2500.0, 5000.0, 7500.0,
+    10000.0,
+];
+
 #[ignore = "https://github.com/open-telemetry/opentelemetry-rust/pull/2224"]
 #[test]
 fn prometheus_exporter_integration() {
@@ -123,6 +132,7 @@ fn prometheus_exporter_integration() {
                     .f64_histogram("histogram_baz")
                     .with_description("a very nice histogram")
                     .with_unit("By")
+                    .with_boundaries(BOUNDARIES.to_vec())
                     .build();
                 histogram.record(23.0, &attrs);
                 histogram.record(7.0, &attrs);
@@ -185,6 +195,7 @@ fn prometheus_exporter_integration() {
                 let histogram = meter
                     .f64_histogram("invalid.hist.name")
                     .with_description("a histogram with an invalid name")
+                    .with_boundaries(BOUNDARIES.to_vec())
                     .build();
                 histogram.record(23.0, &attrs);
             }),
@@ -374,18 +385,6 @@ fn prometheus_exporter_integration() {
         let provider = SdkMeterProvider::builder()
             .with_resource(res)
             .with_reader(exporter)
-            .with_view(
-                new_view(
-                    Instrument::new().name("histogram_*"),
-                    Stream::new().aggregation(Aggregation::ExplicitBucketHistogram {
-                        boundaries: vec![
-                            0.0, 5.0, 10.0, 25.0, 50.0, 75.0, 100.0, 250.0, 500.0, 1000.0,
-                        ],
-                        record_min_max: true,
-                    }),
-                )
-                .unwrap(),
-            )
             .build();
 
         let scope = InstrumentationScope::builder("testmeter")
@@ -559,6 +558,7 @@ fn duplicate_metrics() {
                     .u64_histogram("foo")
                     .with_unit("By")
                     .with_description("meter histogram foo")
+                    .with_boundaries(BYTES_BOUNDARIES.to_vec())
                     .build();
 
                 foo_a.record(100, &[KeyValue::new("A", "B")]);
@@ -567,6 +567,7 @@ fn duplicate_metrics() {
                     .u64_histogram("foo")
                     .with_unit("By")
                     .with_description("meter histogram foo")
+                    .with_boundaries(BYTES_BOUNDARIES.to_vec())
                     .build();
 
                 foo_b.record(100, &[KeyValue::new("A", "B")]);
@@ -631,6 +632,7 @@ fn duplicate_metrics() {
                     .u64_histogram("bar")
                     .with_unit("By")
                     .with_description("meter a bar")
+                    .with_boundaries(BYTES_BOUNDARIES.to_vec())
                     .build();
 
                 bar_a.record(100, &[KeyValue::new("A", "B")]);
@@ -639,6 +641,7 @@ fn duplicate_metrics() {
                     .u64_histogram("bar")
                     .with_unit("By")
                     .with_description("meter b bar")
+                    .with_boundaries(BYTES_BOUNDARIES.to_vec())
                     .build();
 
                 bar_b.record(100, &[KeyValue::new("A", "B")]);
@@ -702,6 +705,7 @@ fn duplicate_metrics() {
                     .u64_histogram("bar")
                     .with_unit("By")
                     .with_description("meter histogram bar")
+                    .with_boundaries(BYTES_BOUNDARIES.to_vec())
                     .build();
 
                 bar_a.record(100, &[KeyValue::new("A", "B")]);
@@ -710,6 +714,7 @@ fn duplicate_metrics() {
                     .u64_histogram("bar")
                     .with_unit("ms")
                     .with_description("meter histogram bar")
+                    .with_boundaries(BYTES_BOUNDARIES.to_vec())
                     .build();
 
                 bar_b.record(100, &[KeyValue::new("A", "B")]);
@@ -759,6 +764,7 @@ fn duplicate_metrics() {
                     .u64_histogram("foo")
                     .with_unit("By")
                     .with_description("meter histogram foo")
+                    .with_boundaries(BOUNDARIES.to_vec())
                     .build();
 
                 foo_histogram_a.record(100, &[KeyValue::new("A", "B")]);