title: AWS Elastic beanstalk requests suddenly started failing
body: <p>Recently my elb environment have decided to not respond to some of the requests. It happens periodically and gets fixed somehow when restart the app servers.
  I am getting below warning in my "var/log/healthd/daemon.log"-</p>
  
  <pre><code>W, [2018-11-03T05:29:56.816559 #7415]  WARN -- : discarding statistic item after validation error (Invalid timestamp): {:id=&gt;"0", :namespace=&gt;"application", :timestamp=&gt;1541222570, :data=&gt;"{\"duration\":10,\"latency_histogram\":[[59.201,1],[59.522,1],[59.556,1],[59.696,1]],\"http_counters\":{\"status_499\":4,\"request_count\":4}}"}
  </code></pre>
  
  <p>I did some searching on this issue and found that it is related to vpc but i am not using one.</p>
  
  <p>Nginx logs have reported HTTP 499 errors. but i guess that is because client is rejecting the requests because of timeout.</p>
  
  <p>Nodejs logs just have some unresponded requests and no errors related to the code or anything else.</p>
  
  <p>Note - I don't know if this is relevant or not but the requests failing are mostly the requests which have some kind of database query. </p>