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1 files changed, 91 insertions, 88 deletions
diff --git a/docs/en/ranch/1.2/guide/internals/index.html b/docs/en/ranch/1.2/guide/internals/index.html index 88466f8e..0f731816 100644 --- a/docs/en/ranch/1.2/guide/internals/index.html +++ b/docs/en/ranch/1.2/guide/internals/index.html @@ -7,7 +7,7 @@ <meta name="description" content=""> <meta name="author" content="Loïc Hoguin based on a design from (Soft10) Pol Cámara"> - <meta name="generator" content="Hugo 0.17" /> + <meta name="generator" content="Hugo 0.26" /> <title>Nine Nines: Internals</title> @@ -67,99 +67,102 @@ <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 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> + + + <nav style="margin:1em 0"> |