10K concurrent connections with nginx
<p>I'm building an app on my own and I'd like for it to handle 10K concurrent connections (tested via local machine and locust script)</p>

<p>Hosted on two ubuntu 14.04 servers with nginx reverse proxy and nodeJS app server.</p>

<p>Currently I get to around 3.3K concurrent users before suffering a spike of 500 connection dropped errors.</p>

<p>I achieved load balancing across port connections by running the app on two separate ports and using an upstream directive to spread requests over ports. </p>

<p>However, this has not shown any demonstrated improvement in my numbers.</p>

<p>Question:</p>

<ol>
<li><p>I know that there is a lot of information missing here (I imagine how much bandwidth each user requires). How do I go about gathering the right information to decide this?</p></li>
<li><p>What other option can I consider/learn/implement to generate the biggest gain in possible concurrent users?</p></li>
</ol>

<p>Thanks a lot!</p>