Track historical active user count.

app/models/historical_data.rb

+class HistoricalData < ActiveRecord::Base
+  validate :date, presence: true
+
+  # HistoricalData.during((Date.today - 1.year)..Date.today).average(:active_user_count)
+  scope :during, ->(range) { where(date: range) }
+
+  class << self
+    def track!
+      create!(
+        date:               Date.today,
+        active_user_count:  User.active.count
+      )
+    end
+
+    # HistoricalData.at(Date.new(2014, 1, 1)).active_user_count
+    def at(date)
+      find_by(date: date)
+    end
+  end
+end

app/workers/historical_data_worker.rb

+class HistoricalDataWorker
+  include Sidekiq::Worker
+  include Sidetiq::Schedulable
+
+  recurrence { daily.hour_of_day(12) }
+
+  def perform
+    HistoricalData.track!
+  end
+end

app/workers/ldap_sync_worker.rb

@@ -2,9 +2,7 @@ class LdapSyncWorker
   include Sidekiq::Worker
   include Sidetiq::Schedulable
 
-  # We check if we are in a Sidekiq server process because of a bug in Sidetiq
-  # 0.6.1 which was giving Unicorn trouble (throwing a Redis::InheritedError).
-  if Gitlab.config.ldap.enabled && Sidekiq.server?
+  if Gitlab.config.ldap.enabled
     HOUR = Gitlab.config.ldap.schedule_sync_hour
     MINUTE = Gitlab.config.ldap.schedule_sync_minute
 

db/migrate/20150507194350_create_historical_data.rb

+class CreateHistoricalData < ActiveRecord::Migration
+  def change
+    create_table :historical_data do |t|
+      t.date :date, null: false
+      t.integer :active_user_count
+
+      t.timestamps
+    end
+  end
+end

db/schema.rb

@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20150502064022) do
+ActiveRecord::Schema.define(version: 20150507194350) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -132,6 +132,13 @@ ActiveRecord::Schema.define(version: 20150502064022) do
     t.boolean  "is_sample",            default: false
   end
 
+  create_table "historical_data", force: true do |t|
+    t.date     "date",              null: false
+    t.integer  "active_user_count"
+    t.datetime "created_at"
+    t.datetime "updated_at"
+  end
+
   create_table "identities", force: true do |t|
     t.string   "extern_uid"
     t.string   "provider"

spec/models/historical_data_spec.rb

+require 'spec_helper'
+
+describe HistoricalData do
+  before do
+    (1..12).each do |i|
+      HistoricalData.create!(date: Date.new(2014, i, 1), active_user_count: i * 100)
+    end
+  end
+
+  describe ".during" do
+    it "returns the historical data during the given period" do
+      expect(HistoricalData.during(Date.new(2014, 1, 1)..Date.new(2014, 12, 31)).average(:active_user_count)).to eq(650)
+    end
+  end
+
+  describe ".at" do
+    it "returns the historical data at the given date" do
+      expect(HistoricalData.at(Date.new(2014, 8, 1)).active_user_count).to eq(800)
+    end
+  end
+
+  describe ".track!" do
+    before do
+      allow(User).to receive(:active).and_return([1,2,3,4,5])
+    end
+
+    it "creates a new historical data record" do
+      HistoricalData.track!
+
+      data = HistoricalData.last
+      expect(data.date).to eq(Date.today)
+      expect(data.active_user_count).to eq(5)
+    end
+  end
+end