Switched to Redis cache in production (#761)

config/environments/production.rb

@@ -16,7 +16,22 @@ Rails.application.configure do
   config.consider_all_requests_local       = false
   config.action_controller.perform_caching = true
 
-  config.cache_store = :memory_store
+  if ENV['REDIS_URL'].present?
+    # Set up Redis cache store
+    config.cache_store = :redis_cache_store, { url: ENV['REDIS_URL'],
+
+      connect_timeout:    30,  # Defaults to 20 seconds
+      read_timeout:       0.2, # Defaults to 1 second
+      write_timeout:      0.2, # Defaults to 1 second
+      reconnect_attempts: 1,   # Defaults to 0
+
+      error_handler: lambda { |method:, returning:, exception:|
+        config.logger.warn "Support: Redis cache action #{method} failed and returned '#{returning}': #{exception}"
+      } }
+  else
+    config.cache_store = :memory_store
+  end
+
   config.public_file_server.headers = {
     'Cache-Control' => "public, max-age=#{1.years.to_i}"
   }