title: AWS Workflows Not Executing
body: <p>I have about 300 workflows running, about half of them failed soon after I made the call to start workflows. I expected them to fail because one of activities did not return the desired result to proceed the next activity. </p>
  
  <p>BUT another half of them list as Active Executions, for an hour and then all went Time Out (because I set the workflow time out 1hr), during that hour, it seems like the workflows got choked and stop even they are listed as active. </p>
  
  <p>I am trying to understand this behavior but I am not sure why it happened. Is it because the workflow workers get stuck somewhere?</p>