diff options
| author | Loïc Hoguin <[email protected]> | 2017-01-22 13:51:38 +0100 |
|---|---|---|
| committer | Loïc Hoguin <[email protected]> | 2017-01-22 13:51:38 +0100 |
| commit | 7bb98d0476dbe4ee5e9317e42ca17e4a7d717e0d (patch) | |
| tree | 29b5fe0d72b65b9382d8b4e1d66a560a55557b77 /articles/dont-let-it-crash/index.html | |
| parent | 1e5b5eb16cd528185246ad2b6cb356696ecafab6 (diff) | |
| download | ninenines.eu-7bb98d0476dbe4ee5e9317e42ca17e4a7d717e0d.tar.gz ninenines.eu-7bb98d0476dbe4ee5e9317e42ca17e4a7d717e0d.tar.bz2 ninenines.eu-7bb98d0476dbe4ee5e9317e42ca17e4a7d717e0d.zip | |
Publish the "Don't let it crash" article
Diffstat (limited to 'articles/dont-let-it-crash/index.html')
| -rw-r--r-- | articles/dont-let-it-crash/index.html | 281 |
1 files changed, 281 insertions, 0 deletions
diff --git a/articles/dont-let-it-crash/index.html b/articles/dont-let-it-crash/index.html new file mode 100644 index 00000000..9fe54196 --- /dev/null +++ b/articles/dont-let-it-crash/index.html @@ -0,0 +1,281 @@ +<!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 0.17" /> + + <title>Nine Nines: Don't let it crash</title> + + <link href='https://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 class="active"><a title="Hear my thoughts" href="/articles">Articles</a></li> + <li><a title="Watch my talks" href="/talks">Talks</a></li> + <li><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"> +<div class="container"> +<div class="row"> +<div class="span9 maincol"> + +<article class="blog_item"> +<header> + <h1 class="lined-header"><span>Don't let it crash</span></h1> + <p class="date"> + <span class="day">22</span> + <span class="month">Jan</span> + </p> +</header> + +<div class="paragraph"><p>We have a specific mindset when writing Erlang
+programs. We focus on the normal execution of the
+program and don’t handle most of the errors that may
+occur. We sometimes call this normal execution the
+<em>happy path</em>.</p></div>
+<div class="paragraph"><p>The general pattern behind writing only for the
+<em>happy path</em>, letting the VM catch errors (writing
+them to a log for future consumption) and then
+having a supervisor restart the processes that
+failed from a clean state, has a name. We call it
+<em>let it crash</em>; and it drives many of our design
+decisions.</p></div>
+<div class="paragraph"><p>It’s a really great way to program and the results
+are fantastic compared to most other programming
+languages. And yet, <em>let it crash</em> barely convinced
+anyone that they should use Erlang. Why would that
+be?</p></div>
+<div class="paragraph"><p>You may already know that Cowboy is capable of
+handling at least 2 million Websocket connections
+on a single server. This is in large part thanks
+to the capabilities of the VM. Still, 2 million
+is good, much better than most other servers can
+do.</p></div>
+<div class="paragraph"><p>Cowboy is not just a Websocket server; it’s also
+an HTTP and HTTP/2 server, and it handles many
+related features like long polling or the parsing
+of most request headers.</p></div>
+<div class="paragraph"><p>Can you guess how large the Cowboy codebase is,
+without looking at the source?</p></div>
+<div class="paragraph"><p>Do make sure you have a clear answer in your mind
+before you go check.</p></div>
+<div class="paragraph"><p>Good, you are back. Now what were the results? If
+I am correct, you overestimated the size of Cowboy.
+Cowboy is in fact about five thousand lines of code.
+You probably thought it was at least ten thousand.
+About eighty percent of readers will have
+overestimated the size of Cowboy. And you did only
+because I mentioned it can handle millions of
+Websocket connections.</p></div>
+<div class="paragraph"><p>Numerous studies show this effect. Just mentioning
+the large number already prepared your mind to think
+in that direction. Repeating the number made you
+focus even more on it. Then the question asked for
+a number, which ended up larger than the reality.</p></div>
+<div class="paragraph"><p>The same effect can be applied to negotiation for
+example. You generally want to start by giving your
+offer (and not let the other party initiate) and
+you want to give a really large number first. You
+can also prepare your customer by mentioning an even
+larger number in the previous discussion.</p></div>
+<div class="paragraph"><p>And it’s not just numbers either. An experiment
+showed that just by looking at an image of clouds,
+customers of a pillow store were buying pillows
+more comfortable (and more expensive) than those
+who didn’t see that image.</p></div>
+<div class="paragraph"><p>This is the power of associations. It is covered in
+much larger detail in the books
+<a href="https://www.amazon.com/Influence-Psychology-Persuasion-Robert-Cialdini/dp/006124189X">Influence</a>
+and
+<a href="https://www.amazon.com/Pre-Suasion-Revolutionary-Way-Influence-Persuade/dp/1501109790">Pre-suasion</a>.
+I highly recommend reading those and applying what
+you learn to your daily life. I’m definitely not
+a professional psychologist so take this post with
+a grain of salt.</p></div>
+<div class="paragraph"><p>When selling Erlang, whether we are selling it to
+a customer or trying to convince a developer friend
+to start using it, we often talk about how Erlang
+<em>lets you sleep at night</em>, that it is auto healing
+and always gets fantastic uptimes.</p></div>
+<div class="paragraph"><p>And then we talk about <em>let it crash</em>.</p></div>
+<div class="paragraph"><p>And we describe what it means.</p></div>
+<div class="paragraph"><p>We might as well just say that Erlang crashes a lot
+and then take the door. It would have the same effect.
+It doesn’t even stop at programs crashing. You know
+what else crashes? Cars, planes, trains. Often with
+disastrous consequences. Is that really the message
+we want to convey?</p></div>
+<div class="paragraph"><p>They even <a href="https://img.youtube.com/vi/oEUBW2lCkIk/0.jpg">printed it on a t-shirt</a>!
+Keep calm and let it crash. It’s the kind of t-shirt
+you probably shouldn’t wear in an airport, and for good
+reasons. A few people did, then realized what they were
+wearing and were not too smug about it.</p></div>
+<div class="paragraph"><p>And yet this is how we sell Erlang.</p></div>
+<div class="paragraph"><p>A better way would be to focus on the positives, of
+course, but also to make sure that those positives
+are phrased in a way that prevents bad associations
+to be formed in people’s minds.</p></div>
+<div class="paragraph"><p>Instead of <em>let it crash</em>, you can say that Erlang
+has <em>auto healing mechanisms</em>. Healing is a good
+thing and accurately describes what happens in the
+system.</p></div>
+<div class="paragraph"><p>Should you need to go into more details, you will
+probably want to avoid <em>recover from crashes</em> and
+instead say <em>recover from exceptions</em>. Exceptions
+are a pretty neutral word and, should you explain
+what you mean by that, you can talk about exceptions
+that occur for reasons unrelated to Erlang, like
+hardware failure or network instability.</p></div>
+<div class="paragraph"><p>The trick is to always use positive words and
+phrases to describe Erlang, and to use external
+factors to explain how Erlang deals with failures.
+Never mention the failures internal to Erlang
+systems unless you are asked specifically, in
+which case you can say that the auto healing
+applies to all exceptions.</p></div>
+<div class="paragraph"><p>The <em>let it crash</em> philosophy is great when
+learning Erlang or when writing fault-tolerant
+systems. But it’s not going to convince anyone
+to use it unless they were already looking for
+it.</p></div>
+<div class="paragraph"><p>Do you like this post? Tell me on Twitter. I might
+make more.</p></div>
+ +</article> +</div> + +<div class="span3 sidecol"> +<h3>More articles</h3> +<ul id="articles-nav" class="extra_margin"> + + <li><a href="https://ninenines.eu/articles/dont-let-it-crash/">Don't let it crash</a></li> + + <li><a href="https://ninenines.eu/articles/cowboy-2.0.0-pre.4/">Cowboy 2.0 pre-release 4</a></li> + + <li><a href="https://ninenines.eu/articles/ranch-1.3/">Ranch 1.3</a></li> + + <li><a href="https://ninenines.eu/articles/ml-archives/">Mailing list archived</a></li> + + <li><a href="https://ninenines.eu/articles/website-update/">Website update</a></li> + + <li><a href="https://ninenines.eu/articles/erlanger-playbook-september-2015-update/">The Erlanger Playbook September 2015 Update</a></li> + + <li><a href="https://ninenines.eu/articles/erlanger-playbook/">The Erlanger Playbook</a></li> + + <li><a href="https://ninenines.eu/articles/erlang-validate-utf8/">Validating UTF-8 binaries with Erlang</a></li> + + <li><a href="https://ninenines.eu/articles/on-open-source/">On open source</a></li> + + <li><a href="https://ninenines.eu/articles/the-story-so-far/">The story so far</a></li> + + <li><a href="https://ninenines.eu/articles/cowboy2-qs/">Cowboy 2.0 and query strings</a></li> + + <li><a href="https://ninenines.eu/articles/january-2014-status/">January 2014 status</a></li> + + <li><a href="https://ninenines.eu/articles/farwest-funded/">Farwest got funded!</a></li> + + <li><a href="https://ninenines.eu/articles/erlang.mk-and-relx/">Build Erlang releases with Erlang.mk and Relx</a></li> + + <li><a href="https://ninenines.eu/articles/xerl-0.5-intermediate-module/">Xerl: intermediate module</a></li> + + <li><a href="https://ninenines.eu/articles/xerl-0.4-expression-separator/">Xerl: expression separator</a></li> + + <li><a href="https://ninenines.eu/articles/erlang-scalability/">Erlang Scalability</a></li> + + <li><a href="https://ninenines.eu/articles/xerl-0.3-atomic-expressions/">Xerl: atomic expressions</a></li> + + <li><a href="https://ninenines.eu/articles/xerl-0.2-two-modules/">Xerl: two modules</a></li> + + <li><a href="https://ninenines.eu/articles/xerl-0.1-empty-modules/">Xerl: empty modules</a></li> + + <li><a href="https://ninenines.eu/articles/ranch-ftp/">Build an FTP Server with Ranch in 30 Minutes</a></li> + + <li><a href="https://ninenines.eu/articles/tictactoe/">Erlang Tic Tac Toe</a></li> + +</ul> + +<h3>Feedback</h3> +<p>Feel free to <a href="mailto:[email protected]">email us</a> +if you found any mistake or need clarification on any of the +articles.</p> + +</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> + |