title: Reliability of atomic counters in DynamoDB
body: <p>I was considering to use <a href="http://aws.amazon.com/dynamodb/">Amazon DynamoDB</a> in my application, and I have a question regarding its <a href="http://docs.amazonwebservices.com/amazondynamodb/latest/developerguide/WorkingWithDDItems.html">atomic counters</a> reliability.</p>
  
  <p>I'm building a distributed application that needs to <strong>concurrently</strong>, and <strong>consistently</strong>, increment/decrement a counter stored in a Dynamo's attribute. 
  I was wondering how reliable the Dynamo's atomic counter is in an heavy concurrent environment, where the concurrency level is extremely high (let's say, for example, an average rate of 20k concurrent hits - to get the idea, that would be almost 52 billions increments/decrements per month). </p>
  
  <p>The counter should be super-reliable and <em>never</em> miss a hit. Has somebody tested DynamoDB in such critical environments?</p>
  
  <p>Thanks</p>