Return from Geo::ProjectSyncWorker#perform if storage is unhealthy

ee/app/workers/geo/project_sync_worker.rb

@@ -21,6 +21,12 @@ module Geo
         return
       end
 
+      shard_name = project.repository_storage
+      unless Gitlab::Geo::ShardHealthCache.healthy_shard?(shard_name)
+        log_error("Project shard '#{shard_name}' is unhealthy, skipping syncing", project_id: project_id)
+        return
+      end
+
       mark_disabled_wiki_as_synced(registry)
 
       Geo::RepositorySyncService.new(project).execute if registry.repository_sync_due?(scheduled_time)

ee/changelogs/unreleased/4957-projectsyncworker-should-skip-projects-that-have-a-broken-gitaly-shard.yml

+---
+title: Prevent Geo from unnecessarily syncing expired CI job artifacts
+merge_request:
+author:
+type: performance

ee/spec/workers/geo/project_sync_worker_spec.rb

@@ -3,10 +3,17 @@ require 'rails_helper'
 RSpec.describe Geo::ProjectSyncWorker do
   describe '#perform' do
     let(:project) { create(:project) }
+    let(:project_with_broken_storage) { create(:project, :broken_storage) }
     let(:repository_sync_service) { spy }
     let(:wiki_sync_service) { spy }
 
     before do
+      allow(Gitlab::Geo::ShardHealthCache).to receive(:healthy_shard?)
+        .with(project.repository_storage).once.and_return(true)
+
+      allow(Gitlab::Geo::ShardHealthCache).to receive(:healthy_shard?)
+        .with(project_with_broken_storage.repository_storage).once.and_return(false)
+
       allow(Geo::RepositorySyncService).to receive(:new)
         .with(instance_of(Project)).once.and_return(repository_sync_service)
 
@@ -20,6 +27,16 @@ RSpec.describe Geo::ProjectSyncWorker do
       end
     end
 
+    context 'when the shard associated to the project is unhealthy' do
+      it 'logs an error and returns' do
+        expect(subject).to receive(:log_error).with("Project shard '#{project_with_broken_storage.repository_storage}' is unhealthy, skipping syncing", project_id: project_with_broken_storage.id)
+        expect(repository_sync_service).not_to receive(:execute)
+        expect(wiki_sync_service).not_to receive(:execute)
+
+        subject.perform(project_with_broken_storage.id, Time.now)
+      end
+    end
+
     context 'when project repositories has never been synced' do
       it 'performs Geo::RepositorySyncService for the given project' do
         subject.perform(project.id, Time.now)