update prompt_queue to expire every after 30 days

on every read or write we update the expiration to 30 days from that point, so it'll only expire after 30 days of inactivity

update prompt_queue to expire every after 30 days
on every read or write we update the expiration to 30 days from that point, so it'll only expire after 30 days of inactivity
Luke Baker
1 parent cf825616
Showing 1 changed file with 7 additions and 2 deletions Show diff stats
app/models/question.rb
@@ -37,6 +37,8 @@ class Question &lt; ActiveRecord::Base
   # regenerating prompts too frequently
   @@percent_full = 0.9
   @@num_prompts = 1000
+  # expire prompts after 30 days of no use
+  @@expire_prompt_cache_in_seconds = 60 * 60 * 24 * 30
   named_scope :created_by, lambda { |id|
     {:conditions => { :local_identifier => id } }
@@ -504,6 +506,7 @@ class Question &lt; ActiveRecord::Base
     # 2 because redis starts indexes at 0
     new_size = (@@num_prompts * @@percent_full - 2).floor
     $redis.ltrim(self.pq_key, 0, new_size)
+    $redis.expire(self.pq_key, @@expire_prompt_cache_in_seconds)
   end
   def add_prompt_to_queue
@@ -518,6 +521,7 @@ class Question &lt; ActiveRecord::Base
       prompts.each do |prompt|
         $redis.rpush(self.pq_key, prompt.id)
       end
+      $redis.expire(self.pq_key, @@expire_prompt_cache_in_seconds)
       return prompts
     end
   end
@@ -526,8 +530,9 @@ class Question &lt; ActiveRecord::Base
     begin
        prompt_id = $redis.lpop(self.pq_key)
        prompt = prompt_id.nil? ? nil : Prompt.find(prompt_id.to_i)
-          end until (prompt.nil? || prompt.active?)
-          prompt
+    end until (prompt.nil? || prompt.active?)
+    $redis.expire(self.pq_key, @@expire_prompt_cache_in_seconds)
+    prompt
   end
   def record_prompt_cache_miss