[deploy] Optimization:Break Send User Digest Emails in Single Jobs (#10043)

app/labor/email_digest.rb

@@ -8,19 +8,8 @@ class EmailDigest
   end
 
   def send_periodic_digest_email
-    @users.find_each do |user|
-      user_email_heuristic = EmailLogic.new(user).analyze
-      next unless user_email_heuristic.should_receive_email?
-
-      articles = user_email_heuristic.articles_to_send
-      begin
-        next unless user.email_digest_periodic?
-
-        DigestMailer.with(user: user, articles: articles).digest_email.deliver_now
-      rescue StandardError => e
-        Honeybadger.context({ user_id: user.id, article_ids: articles.map(&:id) })
-        Honeybadger.notify(e)
-      end
+    @users.ids.each do |user_id|
+      Email::SendUserDigestWorker.perform_async(user_id)
     end
   end
 

app/workers/email/enqueue_digest_worker.rb

@@ -0,0 +1,11 @@
+module Email
+  class EnqueueDigestWorker
+    include Sidekiq::Worker
+
+    sidekiq_options queue: :medium_priority, retry: 15
+
+    def perform
+      EmailDigest.send_periodic_digest_email
+    end
+  end
+end

app/workers/email/send_user_digest_worker.rb

@@ -0,0 +1,23 @@
+module Email
+  class SendUserDigestWorker
+    include Sidekiq::Worker
+
+    sidekiq_options queue: :low_priority, retry: 15, lock: :until_executing
+
+    def perform(user_id)
+      user = User.find_by(id: user_id)
+      return unless user&.email_digest_periodic? && user&.registered?
+
+      user_email_heuristic = EmailLogic.new(user).analyze
+      return unless user_email_heuristic.should_receive_email?
+
+      articles = user_email_heuristic.articles_to_send
+      begin
+        DigestMailer.with(user: user, articles: articles).digest_email.deliver_now
+      rescue StandardError => e
+        Honeybadger.context({ user_id: user.id, article_ids: articles.map(&:id) })
+        Honeybadger.notify(e)
+      end
+    end
+  end
+end

app/workers/send_email_digest_worker.rb

@@ -1,9 +0,0 @@
-class SendEmailDigestWorker
-  include Sidekiq::Worker
-
-  sidekiq_options queue: :medium_priority, retry: 15
-
-  def perform
-    EmailDigest.send_periodic_digest_email
-  end
-end

config/schedule.yml

@@ -94,7 +94,7 @@ daily_home_cache_bust:
     - "/"
 send_email_digest:
   cron: "30 11 * * 3,4,5,6" # 11:30 am UTC Wed, Thurs, Fri, Sat, Sun
-  class: "SendEmailDigestWorker"
+  class: "Email::EnqueueDigestWorker"
 remove_old_notifications:
   cron: "0 5 * * *" # daily at 5 am UTC
   class: "Notifications::RemoveOldNotificationsWorker"

spec/labor/email_digest_spec.rb

@@ -1,47 +1,12 @@
 require "rails_helper"
 
 RSpec.describe EmailDigest, type: :labor do
-  let(:user) { create(:user, email_digest_periodic: true) }
-  let(:author) { create(:user) }
-
-  let(:mailer) { double }
-  let(:message_delivery) { double }
-
-  before do
-    allow(DigestMailer).to receive(:with).and_return(mailer)
-    allow(mailer).to receive(:digest_email).and_return(message_delivery)
-    allow(message_delivery).to receive(:deliver_now)
-  end
-
   describe "::send_digest_email" do
-    context "when there's article to be sent" do
-      before { user.follow(author) }
-
-      it "send digest email when there are at least 3 hot articles" do
-        articles = create_list(:article, 3, user_id: author.id, public_reactions_count: 20, score: 20)
-
-        described_class.send_periodic_digest_email
-
-        expect(DigestMailer).to have_received(:with).with(user: user, articles: articles)
-        expect(mailer).to have_received(:digest_email)
-        expect(message_delivery).to have_received(:deliver_now)
-      end
-
-      it "does not send email when user does not have email_digest_periodic" do
-        articles = create_list(:article, 3, user_id: author.id, public_reactions_count: 20, score: 20)
-        user.update_column(:email_digest_periodic, false)
-        described_class.send_periodic_digest_email
-
-        expect(DigestMailer).not_to have_received(:with).with(user: user, articles: articles)
-      end
-
-      it "does not send email when user is not registered" do
-        articles = create_list(:article, 3, user_id: author.id, public_reactions_count: 20, score: 20)
-        user.update_column(:registered, false)
-        described_class.send_periodic_digest_email
-
-        expect(DigestMailer).not_to have_received(:with).with(user: user, articles: articles)
-      end
+    it "enqueues Email::SendUserDigestWorker" do
+      user = create(:user, email_digest_periodic: true)
+      allow(Email::SendUserDigestWorker).to receive(:perform_async)
+      described_class.send_periodic_digest_email
+      expect(Email::SendUserDigestWorker).to have_received(:perform_async).with(user.id)
     end
   end
 end

spec/workers/email/enqueue_digest_worker_spec.rb

@@ -1,6 +1,6 @@
 require "rails_helper"
 
-RSpec.describe SendEmailDigestWorker, type: :worker do
+RSpec.describe Email::EnqueueDigestWorker, type: :worker do
   let(:worker) { subject }
 
   include_examples "#enqueues_on_correct_queue", "medium_priority"

spec/workers/email/send_user_digest_worker_spec.rb

@@ -0,0 +1,49 @@
+require "rails_helper"
+
+RSpec.describe Email::SendUserDigestWorker, type: :worker do
+  let(:worker) { subject }
+  let(:user) { create(:user, email_digest_periodic: true) }
+  let(:author) { create(:user) }
+  let(:mailer) { double }
+  let(:message_delivery) { double }
+
+  before do
+    allow(DigestMailer).to receive(:with).and_return(mailer)
+    allow(mailer).to receive(:digest_email).and_return(message_delivery)
+    allow(message_delivery).to receive(:deliver_now)
+  end
+
+  include_examples "#enqueues_on_correct_queue", "low_priority"
+
+  describe "perform" do
+    context "when there's articles to be sent" do
+      before { user.follow(author) }
+
+      it "send digest email when there are at least 3 hot articles" do
+        articles = create_list(:article, 3, user_id: author.id, public_reactions_count: 20, score: 20)
+
+        worker.perform(user.id)
+
+        expect(DigestMailer).to have_received(:with).with(user: user, articles: articles)
+        expect(mailer).to have_received(:digest_email)
+        expect(message_delivery).to have_received(:deliver_now)
+      end
+
+      it "does not send email when user does not have email_digest_periodic" do
+        articles = create_list(:article, 3, user_id: author.id, public_reactions_count: 20, score: 20)
+        user.update_column(:email_digest_periodic, false)
+        worker.perform(user.id)
+
+        expect(DigestMailer).not_to have_received(:with).with(user: user, articles: articles)
+      end
+
+      it "does not send email when user is not registered" do
+        articles = create_list(:article, 3, user_id: author.id, public_reactions_count: 20, score: 20)
+        user.update_column(:registered, false)
+        worker.perform(user.id)
+
+        expect(DigestMailer).not_to have_received(:with).with(user: user, articles: articles)
+      end
+    end
+  end
+end