From fbdbbc1bb157fcd40327d220c512cecfce59b30c Mon Sep 17 00:00:00 2001
From: Punya Biswal <punya@google.com>
Date: Fri, 22 Sep 2023 14:56:05 -0400
Subject: [PATCH] [exporters/prometheus] Remove explicit timestamps from metric
 points

Fixes #2316
---
 CHANGELOG.md                                  |  2 ++
 .../exporters/prometheus/exporter_utils.h     |  3 ---
 exporters/prometheus/src/exporter_utils.cc    | 19 +++++++------------
 3 files changed, 9 insertions(+), 15 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index f09553ce70..5b2e80326e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -17,6 +17,8 @@ Increment the:
 
 * [DEPRECATION] Deprecate ZPAGES
   [#2291](https://github.com/open-telemetry/opentelemetry-cpp/pull/2291)
+* [EXPORTER] Remove explicit timestamps from metric points exported by Prometheus
+  [#2324](https://github.com/open-telemetry/opentelemetry-cpp/pull/2324)
 
 ## [1.11.0] 2023-08-21
 
diff --git a/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_utils.h b/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_utils.h
index ce7f0a1191..cb7da0b2b5 100644
--- a/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_utils.h
+++ b/exporters/prometheus/include/opentelemetry/exporters/prometheus/exporter_utils.h
@@ -58,7 +58,6 @@ class PrometheusExporterUtils
   static void SetData(std::vector<T> values,
                       const opentelemetry::sdk::metrics::PointAttributes &labels,
                       ::prometheus::MetricType type,
-                      std::chrono::nanoseconds time,
                       ::prometheus::MetricFamily *metric_family);
 
   /**
@@ -70,14 +69,12 @@ class PrometheusExporterUtils
                       const std::vector<double> &boundaries,
                       const std::vector<uint64_t> &counts,
                       const opentelemetry::sdk::metrics::PointAttributes &labels,
-                      std::chrono::nanoseconds time,
                       ::prometheus::MetricFamily *metric_family);
 
   /**
    * Set time and labels to metric data
    */
   static void SetMetricBasic(::prometheus::ClientMetric &metric,
-                             std::chrono::nanoseconds time,
                              const opentelemetry::sdk::metrics::PointAttributes &labels);
 
   /**
diff --git a/exporters/prometheus/src/exporter_utils.cc b/exporters/prometheus/src/exporter_utils.cc
index 966d665df6..6a71ee79b7 100644
--- a/exporters/prometheus/src/exporter_utils.cc
+++ b/exporters/prometheus/src/exporter_utils.cc
@@ -72,7 +72,7 @@ std::vector<prometheus_client::MetricFamily> PrometheusExporterUtils::TranslateT
             sum = nostd::get<int64_t>(histogram_point_data.sum_);
           }
           SetData(std::vector<double>{sum, (double)histogram_point_data.count_}, boundaries, counts,
-                  point_data_attr.attributes, time, &metric_family);
+                  point_data_attr.attributes, &metric_family);
         }
         else if (type == prometheus_client::MetricType::Gauge)
         {
@@ -82,14 +82,14 @@ std::vector<prometheus_client::MetricFamily> PrometheusExporterUtils::TranslateT
             auto last_value_point_data =
                 nostd::get<sdk::metrics::LastValuePointData>(point_data_attr.point_data);
             std::vector<metric_sdk::ValueType> values{last_value_point_data.value_};
-            SetData(values, point_data_attr.attributes, type, time, &metric_family);
+            SetData(values, point_data_attr.attributes, type, &metric_family);
           }
           else if (nostd::holds_alternative<sdk::metrics::SumPointData>(point_data_attr.point_data))
           {
             auto sum_point_data =
                 nostd::get<sdk::metrics::SumPointData>(point_data_attr.point_data);
             std::vector<metric_sdk::ValueType> values{sum_point_data.value_};
-            SetData(values, point_data_attr.attributes, type, time, &metric_family);
+            SetData(values, point_data_attr.attributes, type, &metric_family);
           }
           else
           {
@@ -105,7 +105,7 @@ std::vector<prometheus_client::MetricFamily> PrometheusExporterUtils::TranslateT
             auto sum_point_data =
                 nostd::get<sdk::metrics::SumPointData>(point_data_attr.point_data);
             std::vector<metric_sdk::ValueType> values{sum_point_data.value_};
-            SetData(values, point_data_attr.attributes, type, time, &metric_family);
+            SetData(values, point_data_attr.attributes, type, &metric_family);
           }
           else
           {
@@ -228,12 +228,11 @@ template <typename T>
 void PrometheusExporterUtils::SetData(std::vector<T> values,
                                       const metric_sdk::PointAttributes &labels,
                                       prometheus_client::MetricType type,
-                                      std::chrono::nanoseconds time,
                                       prometheus_client::MetricFamily *metric_family)
 {
   metric_family->metric.emplace_back();
   prometheus_client::ClientMetric &metric = metric_family->metric.back();
-  SetMetricBasic(metric, time, labels);
+  SetMetricBasic(metric, labels);
   SetValue(values, type, &metric);
 }
 
@@ -246,24 +245,20 @@ void PrometheusExporterUtils::SetData(std::vector<T> values,
                                       const std::vector<double> &boundaries,
                                       const std::vector<uint64_t> &counts,
                                       const metric_sdk::PointAttributes &labels,
-                                      std::chrono::nanoseconds time,
                                       prometheus_client::MetricFamily *metric_family)
 {
   metric_family->metric.emplace_back();
   prometheus_client::ClientMetric &metric = metric_family->metric.back();
-  SetMetricBasic(metric, time, labels);
+  SetMetricBasic(metric, labels);
   SetValue(values, boundaries, counts, &metric);
 }
 
 /**
- * Set time and labels to metric data
+ * Set labels to metric data
  */
 void PrometheusExporterUtils::SetMetricBasic(prometheus_client::ClientMetric &metric,
-                                             std::chrono::nanoseconds time,
                                              const metric_sdk::PointAttributes &labels)
 {
-  metric.timestamp_ms = time.count() / 1000000;
-
   // auto label_pairs = ParseLabel(labels);
   if (!labels.empty())
   {