Remove user activities table and use redis instead of PG for recording activities

Refactored specs and added a post deployment migration to remove the activity users table.

3 files changed, 9 insertions, 26 deletions

diff --git a/app/models/user.rb b/app/models/user.rb
index 1dde5c89699..83e17bcb04e 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -101,7 +101,6 @@ class User < ActiveRecord::Base
 
   has_many :assigned_issues,          dependent: :nullify, foreign_key: :assignee_id, class_name: "Issue"
   has_many :assigned_merge_requests,  dependent: :nullify, foreign_key: :assignee_id, class_name: "MergeRequest"
-  has_one :user_activity, dependent: :destroy
 
   # Issues that a user owns are expected to be moved to the "ghost" user before
   # the user is destroyed. If the user owns any issues during deletion, this
@@ -159,7 +158,6 @@ class User < ActiveRecord::Base
   alias_attribute :private_token, :authentication_token
 
   delegate :path, to: :namespace, allow_nil: true, prefix: true
-  delegate :last_activity_at, to: :user_activity, allow_nil: true
 
   state_machine :state, initial: :active do
     event :block do
@@ -951,6 +949,14 @@ class User < ActiveRecord::Base
     end
   end
 
+  def record_activity
+    Gitlab::Redis.with do |redis|
+      redis.zadd('user/activities', Time.now.to_i, self.username)
+    end
+  end
+
+  private
+
   def access_level=(new_level)
     new_level = new_level.to_s
     return unless %w(admin regular).include?(new_level)
diff --git a/app/models/user_activity.rb b/app/models/user_activity.rb
deleted file mode 100644
index c5fdbff0feb..00000000000
--- a/app/models/user_activity.rb
+++ /dev/null
@@ -1,19 +0,0 @@
-class UserActivity < ActiveRecord::Base
-  belongs_to :user, inverse_of: :user_activity
-
-  validates :user, uniqueness: true, presence: true
-  validates :last_activity_at, presence: true
-
-  # Updated version of http://apidock.com/rails/ActiveRecord/Timestamp/touch
-  # That accepts a new record.
-  def touch
-    current_time = current_time_from_proper_timezone
-
-    if persisted?
-      update_column(:last_activity_at, current_time)
-    else
-      self.last_activity_at = current_time
-      save!(validate: false)
-    end
-  end
-end
diff --git a/app/services/users/activity_service.rb b/app/services/users/activity_service.rb
index b81f947cd01..483821b7f01 100644
--- a/app/services/users/activity_service.rb
+++ b/app/services/users/activity_service.rb
@@ -14,13 +14,9 @@ module Users
     private
 
     def record_activity
-      user_activity.touch
+      @author.record_activity
 
       Rails.logger.debug("Recorded activity: #{@activity} for User ID: #{@author.id} (username: #{@author.username}")
     end
-
-    def user_activity
-      UserActivity.find_or_initialize_by(user: @author)
-    end
   end
 end