Firebug is the web developer’s best friend. Obviously, its Javascript related capabilities are awesome but combined with direct CSS editing, it simply saves a lot of pain for an CSS amatuer like me. Even has autocomplete for CSS. Yet, like all software, it has bugs and I think Firebug has some serious performance issues on Ubuntu.
Before discussing my high CPU usage, I want to point out another thing that annoys me at getfirebug.com. Both Firebug and Firefox are open source and Joe Hewitt, the main Firebug developer, is a strong proponent of open source. Right? Then why does the screenshot on the front page show Firebug running on a Windows XP computer (look below; notice the scrollbars). I am not saying this is wrong but I hope they would change their screenshots to show the better things in this world.
I run Firefox 2.x on Ubuntu Edgy and I found that the CPU usage for Firefox increases as I continue using Firebug. When I am working on a javascript intensive project, the CPU usage starts increasing slowly and after one hour, the computer starts lagging, Firefox’s CPU usage jumps to about 80% and the whole system becomes unusable. Following this, I am forced to restart my computer, reopen all my files and applications. Really irritating when you have to restart your computer 10 times a day!!
I found out that there are others who have had a similar problem but Firebug developers do not seem to have responded to this problem yet. Stefan Scholl says this at the Firebug discussion group:
The last weeks I have encountered a high load for Firefox 2.0.0.x
(Mozilla.org’s binary distribution, installed under KUbuntu LTS). First everything is OK. But after some time the machine gets slower and slower. top is showing me a high cpu usage for the firefox process. Even when I then load “about:” in every open tab (one to three open tabs) and do nothing.
I really hope this issue is fixed in the final 1.0 release. Otherwise, I might have to start looking for alternatives. Although they may not be equally capable, it is impossible to work when you have to restart your box every hour.
18 Comments
January 1, 2007 at 11:18 pm
This isn’t a bug in FireBug. I’ve tested it and wrote a response into the FireBug blog.
The message you refer to didn’t show up in the Google group for a long time. Not a good place for real discussions, so I haven’t read the group after waiting quite some time.
Just start a new Firefox, find the process ID of firefox-bin and then “strace -p -o tracefile”. Hit CTRL-C after about half a minute. Firefox is really busy. In high load situations (after running Firefox for a longer time) the trace-file gets significant bigger in the same amount of time.
I’ve searched Mozilla.org’s bugzilla and there are many(!) different CPU-hogging stories there. Over the last few years and with different versions of Firefox.
January 1, 2007 at 11:24 pm
The comment system killed parts of my strace-example. There has to be the process ID after option “-p”.
January 2, 2007 at 8:10 am
I have to agree with Stefan that this doesn’t look like a Firebug bug. Firebug is written in 100% pure JavaScript, and there is no platform specific code. While it’s very possible I’m doing something wrong in the script, if it manifests in a CPU overheating only on Linux, then that is a bug in Firefox’s Linux-specific internals.
A few other notes in response to your post…
There is no “they” when it comes to Firebug (yet), it’s a one man project. I stress this so that you understand that I have limited time to test under every possible configuration. Part of why I open sourced it was to find help in this area.
As far as the screen shots go… I do not use Linux and I have yet to find the desire to do so, but I also do not use Windows. Firebug was developed entirely on Mac OS X, my OS of choice for 4 years and counting. The real question should be, “Why didn’t you take the screen shots on a Mac?” The answer is, more people use Windows, and I wanted the screen shots to appear relevant to the majority.
I’m really sorry that Firebug has become troublesome on Ubuntu and I hope that those of you who use it can help me to identify the problem so we can fix it.
January 5, 2007 at 10:31 am
Thanks for the response, Joe (woohoo…this is so cool..i am a fan of you and Blake Ross..so cool) and Stefan. I was away for a while so I just looked at your comments.If it’s not a firebug issue, I will try to figure out the problem on my system soon. Sorry for the false accusations (the screenshots, too). I was frustrated when I wrote this.
January 20, 2007 at 5:56 am
you are lucky firebug sorta works for you – even though pressing f12 does nothing on 64bit firefox, though merely having the extension loaded is enough to break JQuery’s AJAX, and proably AJAX in general (noticed it on amazon’s book preview pages too). hopefully some kind of profiling/debugging guru can get firebug working properly on linux..i realize its free, but getting on without firebug doing web development is significantly more time-consuming..
January 20, 2007 at 5:58 am
and yeah. mozilla is a CPU hog? who knew?!?!
January 20, 2007 at 6:00 am
odd logic there Joe – i’d suspect most web developers are using MAcBookPros and are lined up to buy their iPhones
January 20, 2007 at 6:02 am
and re the firefox mem usage – yeah, ive got a ulimit script to kill it when it hits 800 mb, any higher, and the swap hell happens – the only way to get out of that is a hard power. the other problem is merely quitting firefox is not enough, since X will still be using like 400 mb of ram that it never gives back . so you have to kill all of X too.. god. what a sad state of affairs open source web browsers are in 2007…im about to get a job at STarbucks so i can pay someone to add CSS and JS to Dillo..
February 23, 2007 at 11:11 pm
I’ve also noticed problems with CPU usage in Windows XP.
May 2, 2007 at 3:39 pm
I have noticed the same symptoms on Windows XP in firefox 2.0.0.3 When firebug is enabled firefox cpu usage averages between 10 and 30% jumping to 50 on js heavy pages. Furthermore, when firebug is enabled pages rendered considerbly slower. When it’s disabled pages render faster and cpu usage for firefox hovers between
May 2, 2007 at 3:39 pm
May 2, 2007 at 3:41 pm
<1% and 4%, spiking to 25% on page renders
June 24, 2007 at 6:50 pm
Massive issues for me under ubuntu and windows xp for me. Constant restarts of firefox on both platforms. Gmail under ubuntu/firefox is unbearable as well.
I love firefox though, and I deal with it.
June 19, 2008 at 4:26 am
Firebug works great on Firefox 3. Everything seems to be fixed.
November 15, 2008 at 10:35 pm
I get the same problem on Max OS X 10.5.5 with Firefox 3.04 using Google’s gmail or slashdot.org with firebug freshly installed. It goes to 99% CPU and the pages never load–I have to kill the firefox process. They work as expected when I uninstall firebug.
Other simpler websites I use don’t have this problem. Wherever the fault lies, I cannot leave firebug installed.
November 16, 2008 at 8:55 am
Bill: I’m not sure what the exact problem is but Firebug does warn that enabling it for GMail will slow down the page considerably. Since you can enable/disable Firebug for each site independently, I think you can continue using Firebug despite these annoyances.
April 27, 2009 at 6:00 am
You are a very smart person!
October 20, 2009 at 11:59 pm
I am having a few CPU usage issues with firebug on CentOS 5.3. If I disable the add-on, then my CPU usage returns to normal, if I leave the add-on enabled but disable firebug for all websites, I get quite heavy spikes.
More than happy to help debug if you want and find out exactly where it seems to be CPU heavy, is there a debugger for a debugger