title: MongoDB caching counters
body: <p>I'm writing a visit counter for products on a website which uses MongoDB as its' DB-Engine.</p>
  
  <p><a href="http://www.mongodb.org/display/DOCS/Caching" rel="nofollow">Here</a> it says that Mongo keeps frequently accessed stuff in memory and has an integrated in-memory caching engine.</p>
  
  <p>So can I just relay on this integrated caching system and dumbly set the counters up on every visit or does one still need another caching layer on a high-traffic environment?</p>