Nginx cache, redis_pass
<p>I have been banging my head against a wall all day.</p>

<p>I am using the following nginx configuration to test something</p>

<pre><code>location  /help {
  set $redis_key "cache:$scheme://$host$request_uri";
  default_type   text/html;
  redis_pass 127.0.0.1:6379;
  error_page 404 = @upstream;
</code></pre>

<p>}</p>

<p>There is a key and value inside my redis instance for the cache:$scheme.... (in my case cache:<a href="http://localhost/help" rel="nofollow">http://localhost/help</a>)</p>

<p>I know they exist because I can monitor redis-cli for the nginx redis request, copy the <code>"get" "cache:http://localhost/help"</code>, paste it into another redis-cli window and get the expected response.</p>

<p>The problem comes with nginx, it's not getting the response. Again I can see it connect from inside <code>redis-cli -&gt; monitor</code> and I know the key and value exist.</p>

<p>From the nginx error log I can see this</p>

<pre><code>2016/04/08 16:52:42 [notice] 9304#0: worker process 6328 exited with  code 0
2016/04/08 16:52:42 [notice] 9304#0: signal 29 (SIGIO) received
terminate called after throwing an instance of 'std::length_error'
  what():  basic_string::append
2016/04/08 16:52:49 [notice] 9304#0: signal 17 (SIGCHLD) received
2016/04/08 16:52:49 [alert] 9304#0: worker process 7328 exited on signal 6 (core dumped)
2016/04/08 16:52:49 [notice] 9304#0: start worker process 7516
2016/04/08 16:52:49 [notice] 9304#0: signal 29 (SIGIO) received
terminate called after throwing an instance of 'std::length_error'
  what():  basic_string::append
2016/04/08 16:52:50 [notice] 9304#0: signal 17 (SIGCHLD) received
2016/04/08 16:52:50 [alert] 9304#0: worker process 7335 exited on signal 6 (core dumped)
2016/04/08 16:52:50 [notice] 9304#0: start worker process 7544
2016/04/08 16:52:50 [notice] 9304#0: signal 29 (SIGIO) received
terminate called after throwing an instance of 'std::length_error'
  what():  basic_string::append
</code></pre>

<p>Has this appened to anyone else or can someone kick me in the right direction?</p>

<p>Thanks in advance</p>