Instrument other Gitlab::Elastic classes

CHANGELOG-EE

 Please view this file on the master branch, on stable branches it's out of date.
 v 8.12.0 (Unreleased)
   - [ES] Instrument Elasticsearch::Git::Repository
+  - [ES] Instrument other Gitlab::Elastic classes
 
 v 8.11.5
   - API: Restore backward-compatibility for POST /projects/:id/members when membership is locked

config/initializers/metrics.rb

@@ -154,8 +154,13 @@ if Gitlab::Metrics.enabled?
 
     config.instrument_instance_methods(Search::GlobalService)
     config.instrument_instance_methods(Search::ProjectService)
+
     config.instrument_instance_methods(Gitlab::Elastic::SearchResults)
     config.instrument_instance_methods(Gitlab::Elastic::ProjectSearchResults)
+    config.instrument_instance_methods(Gitlab::Elastic::Indexer)
+    config.instrument_instance_methods(Gitlab::Elastic::SnippetSearchResults)
+    config.instrument_methods(Gitlab::Elastic::Helper)
+
     config.instrument_instance_methods(Elastic::ApplicationSearch)
     config.instrument_instance_methods(Elastic::IssuesSearch)
     config.instrument_instance_methods(Elastic::MergeRequestsSearch)