Remove the project label from histogram metrics

app/services/ci/prometheus_metrics/observe_histograms_service.rb

@@ -40,7 +40,7 @@ module Ci
 
       def observe(data)
         histogram = find_histogram(data[:name])
-        histogram.observe({ project: project.full_path }, data[:value].to_f)
+        histogram.observe({}, data[:value].to_f)
       end
 
       def find_histogram(name)

doc/administration/monitoring/prometheus/gitlab_metrics.md

@@ -119,9 +119,9 @@ The following metrics are available:
 | `gitlab_external_http_duration_seconds`                        | Counter   |  13.8 | Duration in seconds spent on each HTTP call to external systems                                       |                                                         |
 | `gitlab_external_http_exception_total`                         | Counter   |  13.8 | Total number of exceptions raised when making external HTTP calls                                     |                                                         |
 | `ci_report_parser_duration_seconds`                            | Histogram |  13.9 | Time to parse CI/CD report artifacts                                                                  | `parser`                                                |
-| `pipeline_graph_link_calculation_duration_seconds`             | Histogram |  13.9 | Total time spent calculating links, in seconds                                                        | `project`                                               |
-| `pipeline_graph_links_total`                                   | Histogram |  13.9 | Number of links per graph                                                                             | `project`                                               |
-| `pipeline_graph_links_per_job_ratio`                           | Histogram |  13.9 | Ratio of links to job per graph                                                                       | `project`                                               |
+| `pipeline_graph_link_calculation_duration_seconds`             | Histogram |  13.9 | Total time spent calculating links, in seconds                                                        |                                                         |
+| `pipeline_graph_links_total`                                   | Histogram |  13.9 | Number of links per graph                                                                             |                                                         |
+| `pipeline_graph_links_per_job_ratio`                           | Histogram |  13.9 | Ratio of links to job per graph                                                                       |                                                         |
 
 ## Metrics controlled by a feature flag
 

spec/services/ci/prometheus_metrics/observe_histograms_service_spec.rb

@@ -81,6 +81,6 @@ RSpec.describe Ci::PrometheusMetrics::ObserveHistogramsService do
   end
 
   def histogram_data(name = :pipeline_graph_link_calculation_duration_seconds)
-    Gitlab::Metrics.registry.get(name)&.get({ project: project.full_path })
+    Gitlab::Metrics.registry.get(name)&.get({})
   end
 end