Use approximate counts for big tables

3 files changed, 16 insertions, 6 deletions

diff --git a/lib/gitlab/database/count.rb b/lib/gitlab/database/count.rb
index c996d786909..f3d37ccd72a 100644
--- a/lib/gitlab/database/count.rb
+++ b/lib/gitlab/database/count.rb
@@ -40,7 +40,7 @@ module Gitlab
           if strategy.enabled?
             models_with_missing_counts = models - counts_by_model.keys
 
-            break if models_with_missing_counts.empty?
+            break counts_by_model if models_with_missing_counts.empty?
 
             counts = strategy.new(models_with_missing_counts).count
 
diff --git a/lib/gitlab/database/count/exact_count_strategy.rb b/lib/gitlab/database/count/exact_count_strategy.rb
index 0276fe2b54f..fa6951eda22 100644
--- a/lib/gitlab/database/count/exact_count_strategy.rb
+++ b/lib/gitlab/database/count/exact_count_strategy.rb
@@ -20,6 +20,8 @@ module Gitlab
           models.each_with_object({}) do |model, data|
             data[model] = model.count
           end
+        rescue *CONNECTION_ERRORS
+          {}
         end
 
         def self.enabled?
diff --git a/lib/gitlab/usage_data.rb b/lib/gitlab/usage_data.rb
index bfcc8efdc96..008e9cd1d24 100644
--- a/lib/gitlab/usage_data.rb
+++ b/lib/gitlab/usage_data.rb
@@ -2,6 +2,8 @@
 
 module Gitlab
   class UsageData
+    APPROXIMATE_COUNT_MODELS = [Label, MergeRequest, Note, Todo].freeze
+
     class << self
       def data(force_refresh: false)
         Rails.cache.fetch('usage_data', force: force_refresh, expires_in: 2.weeks) { uncached_data }
@@ -73,12 +75,9 @@ module Gitlab
             issues: count(Issue),
             keys: count(Key),
             label_lists: count(List.label),
-            labels: count(Label),
             lfs_objects: count(LfsObject),
-            merge_requests: count(MergeRequest),
             milestone_lists: count(List.milestone),
             milestones: count(Milestone),
-            notes: count(Note),
             pages_domains: count(PagesDomain),
             projects: count(Project),
             projects_imported_from_github: count(Project.where(import_type: 'github')),
@@ -86,10 +85,9 @@ module Gitlab
             releases: count(Release),
             remote_mirrors: count(RemoteMirror),
             snippets: count(Snippet),
-            todos: count(Todo),
             uploads: count(Upload),
             web_hooks: count(WebHook)
-          }.merge(services_usage)
+          }.merge(services_usage).merge(approximate_counts)
         }
       end
       # rubocop: enable CodeReuse/ActiveRecord
@@ -164,6 +162,16 @@ module Gitlab
         fallback
       end
       # rubocop: enable CodeReuse/ActiveRecord
+
+      def approximate_counts
+        approx_counts = Gitlab::Database::Count.approximate_counts(APPROXIMATE_COUNT_MODELS)
+
+        APPROXIMATE_COUNT_MODELS.each_with_object({}) do |model, result|
+          key = model.name.underscore.pluralize.to_sym
+
+          result[key] = approx_counts[model] || -1
+        end
+      end
     end
   end
 end