title: What causes sudden delays in AWS SNS?
body: <p>I experience a sudden appearance of huge delays of SNS notifications being pushed to a http endpoint. This started pretty much immediately on June 12, 2017 at around 5pm CET and has not disappeared until now. There are still some immediate deliveries, but since then 10% of all notifications take more than 10 minutes until delivery, 33% more than 1 minute.</p>
  
  <p>Nothing on our code base regarding this behaviour changed around that time. It was even an extremly slow period with only very minor changes because the majority of our developers were on vacation.</p>
  
  <p>What could be the cause of this?</p>
  
  <p>The message amount is small, between 200-1000 per day. Each message is less than 1KB.</p>
  
  <p><a href="https://i.stack.imgur.com/rN42b.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/rN42b.png" alt="Graph ov average SNS delay in seconds"></a></p>