FIX: Jobs.cancel_scheduled_job wasn't working anymore due to our move to using multiple queues

FIX: Don't queue more than 1 'update_gravatar' job per user

app/jobs/base.rb

@@ -244,7 +244,10 @@ module Jobs
   def self.scheduled_for(job_name, params={})
     params = params.with_indifferent_access
     job_class = "Jobs::#{job_name.to_s.camelcase}"
-    Sidekiq::ScheduledSet.new.select do |scheduled_job|
+
+    scheduled_jobs = []
+    Sidekiq::Queue.all.each do |queue|
+      queue.each do |scheduled_job|
         if scheduled_job.klass.to_s == job_class
           matched = true
           job_params = scheduled_job.item["args"][0].with_indifferent_access
@@ -254,12 +257,13 @@ module Jobs
               break
             end
           end
-        matched
-      else
-        false
+          scheduled_jobs << scheduled_job if matched
         end
       end
     end
+
+    scheduled_jobs
+  end
 end
 
 Dir["#{Rails.root}/app/jobs/onceoff/*.rb"].each {|file| require_dependency file }

app/jobs/scheduled/create_missing_avatars.rb

@@ -7,9 +7,10 @@ module Jobs
       UserAvatar.includes(:user)
                 .where(last_gravatar_download_attempt: nil)
                 .order("users.last_posted_at DESC")
-                .limit(5000)
-                .each do |u|
-        u.user.refresh_avatar
+                .find_in_batches(batch_size: 5000) do |user_avatars|
+        user_avatars.each do |user_avatar|
+          user_avatar.user.refresh_avatar
+        end
       end
     end
   end

app/models/user.rb

@@ -753,6 +753,7 @@ class User < ActiveRecord::Base
     avatar = user_avatar || create_user_avatar
 
     if SiteSetting.automatically_download_gravatars? && !avatar.last_gravatar_download_attempt
+      Jobs.cancel_scheduled_job(:update_gravatar, user_id: self.id, avatar_id: avatar.id)
       Jobs.enqueue(:update_gravatar, user_id: self.id, avatar_id: avatar.id)
     end