Move Prometheus initialization after preloading the remaining app

config/application.rb

@@ -34,5 +34,10 @@ module CodeOcean
     config.action_cable.mount_path = '/cable'
 
     config.telegraf.tags = { application: 'codeocean' }
+
+    config.after_initialize do
+      # Initialize the counters according to the db
+      Prometheus::Controller.initialize_metrics
+    end
   end
 end

config/initializers/prometheus.rb

@@ -6,5 +6,4 @@ return if %w[db: assets:].any? { |task| Rake.application.top_level_tasks.to_s.in
 # Add metric callbacks to all models
 ApplicationRecord.include Prometheus::Record
 
-# Initialize the counters according to the db
+# Initialization is performed in config/application.rb
-Prometheus::Controller.initialize_metrics

lib/prometheus/controller.rb

@@ -12,7 +12,6 @@ module Prometheus
       def initialize_metrics
         register_metrics
 
-        Rails.application.eager_load!
         Rails.application.executor.wrap do
           Thread.new do
             initialize_instance_count