title: Getting failed requests with apache benchmark on a load balanced Tornado site but none logged
body: <p>Perhaps this is a question about ab rather than about Tornado but something doesn't make sense. </p>
  
  <p>I run the benchmark like this:</p>
  
  <pre><code>$ ab -n 100 http://localdomainname/ # 2 tornados being 1 nginx
   ...
  Concurrency Level:      1
  Time taken for tests:   0.162 seconds
  Complete requests:      100
  Failed requests:        17
     (Connect: 0, Receive: 0, Length: 17, Exceptions: 0)
  Write errors:           0
  </code></pre>
  
  <p>So according to that 17 of 100 requests failed. </p>
  
  <p>Prior to running the benchamark I reset the log files and look at them again:</p>
  
  <pre><code>$ wc -l /tmp/gkc.access.log 
  100 /tmp/gkc.access.log
  $ cat /tmp/gkc.access.log | grep ' 200 ' | wc -l
  100
  </code></pre>
  
  <p>So, according to Nginx no requests failed! Why is ab saying 17 of 100 failed? </p>
  
  <p>(By the way, 17 out of 100 was just one example. it goes up and down but never 0 which I'd expect)</p>
  
  <p>UPDATE</p>
  
  <p>Having tested with httperf without touching the Tornado+Nginx setup I get 0 failed requests. </p>