Limit URLs, DBUpgrade and HAR beacon in ShowSlow

I added a few features to ShowSlow in a past couple weeks, but being also busy with HowDoable, I didn’t have time to write about them so here you go – a short digest:

Limit URLs using PCRE regexes

You can now limit URLs to be accepted by ShowSlow using PCRE regular expressions (thanks for initial patch from Aaron). All you need to do is to use a regex instead of just prefix in $limitURLs array – ShowSlow will automatically detect that it’s not a URL prefix and match against it using preg_match.

DBUpgrade for easy data schema upgrades

DBUpgradeI’ve started to use another open source project of mine called DBUpgrade to help you with database schema upgrades going from version to version. Going forward, if you’ll need to upgrade the schema, all you’ll have to do is run php dbupgrade.php or just make (which is going to run svn update too). tables.sql will still contain latest schema so feel free to update manually.
DBUpgrade requires MySQLi module to be configured with your PHP, it is also recommended if you’re using MySQL 4.1.3 and later (and you should be).

HAR beacon

And finally, I worked with Jan “Honza” Odvarko who is one of the lead developer of Firebug and related extensions to add HTTP Archive (HAR) support to ShowSlow and beacon support to NetExport Firebug extension (use v0.7b12+) that allows to save contents of Net Panel and later view it. HAR is also supported by HTTPWatch, a tool that created original xml-based export format HAR was based upon.

By default, beacons are sent to but you can reconfigure it to point to your own instance using extensions.firebug.netexport.beaconServerURL Firefox config variable (at about:config).

NetExport beacon menu screenshot

You can see sample result here. For configuration options, see documentation on

That was a lot of stuff – I should be reporting about developments more often.

Go ahead and try it all, let me know how it works and if you have any troubles using these features. If you feel you need more features in ShowSlow, go ahead, submit them to our UserVoice forum and email the mailing list to discuss and gain supporters:

Update: See also post by Honza about this:

3 thoughts on “Limit URLs, DBUpgrade and HAR beacon in ShowSlow”

  1. This is awesome, Honza! What about privacy concerns in posting a HAR file? What should users be concerned about? I can imagine a HTTP trace containing IP addresses, usernames & passwords (esp. for HTTP login pages), cookies, etc. Which of those and other potentially private information are made public? If any of them are, it would be neat if NetExport had an option to strip all of that information. For example, cookies could be replaced with xoxo characters.

  2. Sorry – I meant Honza and Sergey! Can’t wait to hear more from you at Velocity OLC, Sergey. And I hope you’ll join us at the in-real-life Velocity event in June. I’ve been evangelizing to every company I talk to. Great example of open source and crowdsourcing combined.

  3. I agree regarding privacy – it’s probably worth adding extra warning to a beacon similar to YSlow/Page Speed beacons.

    But I also think that it’s important to distinguish being public demo instance and those private installations that people host within their organizations, on private servers and so on. Many users actually have same concerns regarding any data they measure, even non-personalized data, but even actual fact of metering and that’s why they install their own instances.

    Thanks Steve! I very much hope to join you at Velocity – my talk about ShowSlow is accepted so now it’s just a question of getting there ;) Hope Patrick Meenan of AOL Page Test will be there too – there is a lot to share among the projects.

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