My distinguished and decidedly sexy colleague Josh Barratt recently noted that you can use multiple -p flags with strace in order to simultaneously attach to multiple process. This is very useful when you’re trying to debug something like Nginx where there are likely multiple child processes that you want to monitor. If this is something that you think you might find useful, here’s a bash snippet that will make an easy to use straceall command: function straceall { strace $(pidof “${1}” | sed ‘s/\([0-9]*\)/-p \1/g’) } Just put this in your .bashrc, and then you can easily monitor a family of processes with a command such as: straceall php5-fpm if you’re trying to debug say a PHP issue.
Upgrading from Node.js 0.8.x to 0.10.0 From my PPA
The Node.js project recently pushed out a new stable version with the 0.10.0 release. This release supersedes the 0.8.x line and has a bunch of new features and enhancements. In particular, there’s a new Streams API you’ll probably want to check out. Also, the domain module has been elevated to “unstable” status, so you can start checking it out for your error handling. A lot of people seem to use my node PPA to install node on their systems, so I wanted to make a quick note about performing this upgrade.
Proxying WebSockets with Nginx
WebSockets are an exciting new technology designed to make it easier to create real time applications by providing a full-duplex communication channel between the browser and the server. In layman’s terms that means that information can be sent and received by the application at the same time. One of the easiest ways to write apps using WebSockets is to make use of the excellent Socket.io library, which is used in conjunction with Node. The usual strategy when building a Node app is to put Nginx in front of Node as a reverse proxy that serves any static content. This was a problem if you wanted to use WebSockets though, as Nginx didn’t know how to proxy those requests. Until now…
Speed Up Your Site with SPDY and Nginx
Speed is a Good Thing ™ when it comes to your site loading. Generally speaking, if people can’t start interacting with your site quickly, meaning within a few seconds of when they first get there, your engagement numbers are going to plummet. The folks over at Google are keenly aware of this and have therefore introduced a new protocol called SPDY which is designed to make the initial load time of modern web pages faster. It’s already in use at places such as GMail and Twitter, so this is not just a theoretical endeavor. My friends over at Automattic sponsored an initial implementation of SPDY for the Nginx web server, and I’ll explain how to use this cool new tech on your own sites.