Julian Joswig: IT Blog

Yahoo’s best practices for speeding up websites

Julian Joswig — Sun, 08 Jan 2012 12:55:53 +0000

The load time of a webpage is a crucial factor for keeping the visitor on a webpage. Too long load times cause the visitor to quit the webpage because he expects a fast and responsive webpage. Yahoo published a comprehensive guide of webdevelopment best practices that, if applied, reduce load times of webpages enhancing your user’s experience.

Summary of hints for webdevelopment purposes:

Minimize HTTP requests
Combining files reduces HTTP get requests (e.g. one single CSS/JS file, Image sprites instead of multiple single images).
Put stylesheets at the top, scripts at the bottom
Putting CSS files within tag loads images faster and lets the browser render the webpage progressively.
Reduce DNS lookups
Every different hostname causes a DNS lookup request. Consolidate all files on one hostname to reduce the request count to 1 or use IP addresses instead of hostnames or domains
Minify JavaScript and CSS
“Compress” your JavaScript or CSS files by removing unneccessary content, e.g. comments and white spaces. Many web development frameworks (such as Ruby on Rails or CakePHP) ship their own compressing tool, but there are also third-party tools available that minify content on-the-fly. For example check out Minify.

The whole guide with far more best practices and hints is available here: http://developer.yahoo.com/performance/rules.html

Quick hint: GAget – Google Analytics Widget for Mac OS X Dashboard

Julian Joswig — Sun, 01 Jan 2012 17:36:13 +0000

The award winning widget “GAget” provides instant access to Google Analytics statistics without being logged in to GA in your webbrowser. Once added to your Mac OS X dashboard (also multiple-times usable) it fetches the data in realtime (even from the current day) and visualizes them.

For more information visit the author’s website.

Hint: ssh-copy-id and different ssh port

Julian Joswig — Thu, 29 Dec 2011 10:31:18 +0000

ssh-copy-id is a dedicated tool to set up public key authentication via ssh between two linux machines. You will get a problem, if the ssh daemon is listening on a different port (for example: 2222). The standard ssh-copy-id command in Ubuntu Linux doesn’t support a custom SSH port. According to the man page there are only a few parameters available:

NAME ssh-copy-id - install your public key in a remote machine's autho- rized_keys

SYNOPSIS ssh-copy-id [-i [identity_file]] [user@]machine

There is a trick, that does the deal: ssh-copy-id passes on custom parameters directly to ssh by quoting the custom string:
ssh-copy-id -i /path/to/id_foobar.pub "-p 2222 user@server"

You can see, that it is possible to use all known params from ssh to ssh-copy-id, especially needed for custom ssh ports like in this case.