diff options
| author | Loïc Hoguin <[email protected]> | 2016-03-28 15:36:42 +0200 |
|---|---|---|
| committer | Loïc Hoguin <[email protected]> | 2016-03-28 15:36:42 +0200 |
| commit | fe3492a98de29942477b061cd02c92246f4bf85a (patch) | |
| tree | 2255b796a657e6e4dfb72beec1141258d17f1220 /docs/en/ranch/1.2/guide/internals | |
| download | ninenines.eu-fe3492a98de29942477b061cd02c92246f4bf85a.tar.gz ninenines.eu-fe3492a98de29942477b061cd02c92246f4bf85a.tar.bz2 ninenines.eu-fe3492a98de29942477b061cd02c92246f4bf85a.zip | |
Initial commit, new website system
Diffstat (limited to 'docs/en/ranch/1.2/guide/internals')
| -rw-r--r-- | docs/en/ranch/1.2/guide/internals/index.html | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/docs/en/ranch/1.2/guide/internals/index.html b/docs/en/ranch/1.2/guide/internals/index.html new file mode 100644 index 00000000..bd7610c7 --- /dev/null +++ b/docs/en/ranch/1.2/guide/internals/index.html @@ -0,0 +1,227 @@ +<!DOCTYPE html> +<html lang="en"> + +<head> + <meta charset="utf-8"> + <meta name="viewport" content="width=device-width, initial-scale=1.0"> + <meta name="description" content=""> + <meta name="author" content="Loïc Hoguin based on a design from (Soft10) Pol Cámara"> + + <meta name="generator" content="Hugo 0.15" /> + + <title>Nine Nines: Internals</title> + + <link href='http://fonts.googleapis.com/css?family=Open+Sans:400,700,400italic' rel='stylesheet' type='text/css'> + + <link href="/css/bootstrap.min.css" rel="stylesheet"> + <link href="/css/99s.css" rel="stylesheet"> + + <link rel="shortcut icon" href="/img/ico/favicon.ico"> + <link rel="apple-touch-icon-precomposed" sizes="114x114" href="/img/ico/apple-touch-icon-114.png"> + <link rel="apple-touch-icon-precomposed" sizes="72x72" href="/img/ico/apple-touch-icon-72.png"> + <link rel="apple-touch-icon-precomposed" href="/img/ico/apple-touch-icon-57.png"> + + +</head> + + +<body class=""> + <header id="page-head"> + <div id="topbar" class="container"> + <div class="row"> + <div class="span2"> + <h1 id="logo"><a href="/" title="99s">99s</a></h1> + </div> + <div class="span10"> + + <div id="side-header"> + <nav> + <ul> + <li><a title="Hear my thoughts" href="/articles">Articles</a></li> + <li><a title="Watch my talks" href="/talks">Talks</a></li> + <li class="active"><a title="Read the docs" href="/docs">Documentation</a></li> + <li><a title="Request my services" href="/services">Consulting & Training</a></li> + </ul> + </nav> + <ul id="social"> + <li> + <a href="https://github.com/ninenines" title="Check my Github repositories"><img src="/img/ico_github.png" data-hover="/img/ico_github_alt.png" alt="Github"></a> + </li> + <li> + <a title="Keep in touch!" href="http://twitter.com/lhoguin"><img src="/img/ico_microblog.png" data-hover="/img/ico_microblog_alt.png"></a> + </li> + <li> + <a title="Contact me" href="mailto:[email protected]"><img src="/img/ico_mail.png" data-hover="/img/ico_mail_alt.png"></a> + </li> + </ul> + </div> + </div> + </div> + </div> + + +</header> + +<div id="contents" class="two_col"> +<div class="container"> +<div class="row"> +<div id="docs" class="span9 maincol"> + +<h1 class="lined-header"><span>Internals</span></h1> + +<div class="paragraph"><p>This chapter may not apply to embedded Ranch as embedding allows you
+to use an architecture specific to your application, which may or may
+not be compatible with the description of the Ranch application.</p></div>
+<div class="paragraph"><p>Note that for everything related to efficiency and performance,
+you should perform the benchmarks yourself to get the numbers that
+matter to you. Generic benchmarks found on the web may or may not
+be of use to you, you can never know until you benchmark your own
+system.</p></div>
+<div class="sect1">
+<h2 id="_architecture">Architecture</h2>
+<div class="sectionbody">
+<div class="paragraph"><p>Ranch is an OTP application.</p></div>
+<div class="paragraph"><p>Like all OTP applications, Ranch has a top supervisor. It is responsible
+for supervising the <code>ranch_server</code> process and all the listeners that
+will be started.</p></div>
+<div class="paragraph"><p>The <code>ranch_server</code> gen_server is a central process keeping track of the
+listeners and their acceptors. It does so through the use of a public ets
+table called <code>ranch_server</code>. The table is owned by the top supervisor
+to improve fault tolerance. This way if the <code>ranch_server</code> gen_server
+fails, it doesn’t lose any information and the restarted process can
+continue as if nothing happened.</p></div>
+<div class="paragraph"><p>Ranch uses a custom supervisor for managing connections. This supervisor
+keeps track of the number of connections and handles connection limits
+directly. While it is heavily optimized to perform the task of creating
+connection processes for accepted connections, it is still following the
+OTP principles and the usual <code>sys</code> and <code>supervisor</code> calls will work on
+it as expected.</p></div>
+<div class="paragraph"><p>Listeners are grouped into the <code>ranch_listener_sup</code> supervisor and
+consist of three kinds of processes: the listener gen_server, the
+acceptor processes and the connection processes, both grouped under
+their own supervisor. All of these processes are registered to the
+<code>ranch_server</code> gen_server with varying amount of information.</p></div>
+<div class="paragraph"><p>All socket operations, including listening for connections, go through
+transport handlers. Accepted connections are given to the protocol handler.
+Transport handlers are simple callback modules for performing operations on
+sockets. Protocol handlers start a new process, which receives socket
+ownership, with no requirements on how the code should be written inside
+that new process.</p></div>
+</div>
+</div>
+<div class="sect1">
+<h2 id="_number_of_acceptors">Number of acceptors</h2>
+<div class="sectionbody">
+<div class="paragraph"><p>The second argument to <code>ranch:start_listener/6</code> is the number of
+processes that will be accepting connections. Care should be taken
+when choosing this number.</p></div>
+<div class="paragraph"><p>First of all, it should not be confused with the maximum number
+of connections. Acceptor processes are only used for accepting and
+have nothing else in common with connection processes. Therefore
+there is nothing to be gained from setting this number too high,
+in fact it can slow everything else down.</p></div>
+<div class="paragraph"><p>Second, this number should be high enough to allow Ranch to accept
+connections concurrently. But the number of cores available doesn’t
+seem to be the only factor for choosing this number, as we can
+observe faster accepts if we have more acceptors than cores. It
+might be entirely dependent on the protocol, however.</p></div>
+<div class="paragraph"><p>Our observations suggest that using 100 acceptors on modern hardware
+is a good solution, as it’s big enough to always have acceptors ready
+and it’s low enough that it doesn’t have a negative impact on the
+system’s performances.</p></div>
+</div>
+</div>
+<div class="sect1">
+<h2 id="_platform_specific_tcp_features">Platform-specific TCP features</h2>
+<div class="sectionbody">
+<div class="paragraph"><p>Some socket options are platform-specific and not supported by <code>inet</code>.
+They can be of interest because they generally are related to
+optimizations provided by the underlying OS. They can still be enabled
+thanks to the <code>raw</code> option, for which we will see an example.</p></div>
+<div class="paragraph"><p>One of these features is <code>TCP_DEFER_ACCEPT</code> on Linux. It is a simplified
+accept mechanism which will wait for application data to come in before
+handing out the connection to the Erlang process.</p></div>
+<div class="paragraph"><p>This is especially useful if you expect many connections to be mostly
+idle, perhaps part of a connection pool. They can be handled by the
+kernel directly until they send any real data, instead of allocating
+resources to idle connections.</p></div>
+<div class="paragraph"><p>To enable this mechanism, the following option can be used.</p></div>
+<div class="listingblock">
+<div class="title">Using raw transport options</div>
+<div class="content"><!-- Generator: GNU source-highlight 3.1.8
+by Lorenzo Bettini
+http://www.lorenzobettini.it
+http://www.gnu.org/software/src-highlite -->
+<pre><tt>{<span style="color: #FF6600">raw</span>, <span style="color: #993399">6</span>, <span style="color: #993399">9</span>, <span style="color: #990000"><<</span> <span style="font-weight: bold"><span style="color: #000000">30:32</span></span><span style="color: #990000">/</span><span style="color: #FF6600">native</span> <span style="color: #990000">>></span>}</tt></pre></div></div>
+<div class="paragraph"><p>It means go on layer 6, turn on option 9 with the given integer parameter.</p></div>
+</div>
+</div>
+ + + +</div> + +<div class="span3 sidecol"> + + +<h3> + Ranch + 1.2 + + User Guide +</h3> + +<ul> + + <li><a href="/docs/en/ranch/1.2/guide">User Guide</a></li> + + + <li><a href="/docs/en/ranch/1.2/manual">Function Reference</a></li> + + +</ul> + +<h4 id="docs-nav">Navigation</h4> + +<h4>Version select</h4> +<ul> + + + + <li><a href="/docs/en/ranch/1.2/guide">1.2</a></li> + +</ul> + +</div> +</div> +</div> +</div> + + <footer> + <div class="container"> + <div class="row"> + <div class="span6"> + <p id="scroll-top"><a href="#">↑ Scroll to top</a></p> + <nav> + <ul> + <li><a href="mailto:[email protected]" title="Contact us">Contact us</a></li><li><a href="https://github.com/ninenines/ninenines.github.io" title="Github repository">Contribute to this site</a></li> + </ul> + </nav> + </div> + <div class="span6 credits"> + <p><img src="/img/footer_logo.png"></p> + <p>Copyright © Loïc Hoguin 2012-2016</p> + </div> + </div> + </div> + </footer> + + + <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js"></script> + <script src="/js/bootstrap-carousel.js"></script> + <script src="/js/bootstrap-dropdown.js"></script> + <script src="/js/custom.js"></script> + </body> +</html> + + |