GWT In Eclipse Debug Mode All Of A Sudden is Super Slow

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Apr 6, 2011, 3:15:45 PM4/6/11
to Google Web Toolkit
Recently I was running my GWT application in devmode via the Eclipse
plugin in the Google Chrome Browser. Chrome stopped responding and my
browser completely crashed, requiring me to restart my computer. I
restarted my computer and tried to run my GWT application again, but
this time it was SUPER slow. Devmode has always been a little slow,
but now it's at the point where it is not even usable anymore. The
weird part is that it is only when running in debug mode via the
Eclipse plugin, standard run (not debug) via eclipse, the devmode Ant
target, and production depoyment (WAR) work fine.

I have tried to run other GWT applications and now they are all
running unbearably slow now as well. I uninstalled/reinstalled the
Google Plugin, upgraded to Eclipse Helios (was using Galileo),
upgraded to GWT 2.2.0 (was using 2.0.3), etc and nothing has worked.
I am the only one on my team having this issue and we are all running
the EXACT same codebase.

Has anyone encountered this issue before? Any help would be greatly
appreciated. I have spent ~2 days straight trying to figure out this

Environment (at this point I have tried a number of different versions
of the below libraries, all produced the same issue of being too slow
in devmode debugging via Eclipse):
-GWT 2.2.0
-Eclipse Helios w/ Google Plugin for Eclipse 3.6 & GWT SDK 2.2.0
-Google Chrome 10.0.648.204
-GXT 2.2.3 (for GWT 2.2)

Paul J.

Chris Conroy

Apr 7, 2011, 12:27:15 PM4/7/11
to, PTJ
Eclipse's debug hooks can sometimes cause pathological slowdowns if you have a breakpoint set on a method entry point. This can happen for regular java (read: non-GWT) programs as well. Try removing any breakpoints you have set (or at least, removing any on the method entry--you can set them just fine on the first line of the function instead)

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Apr 11, 2011, 9:54:44 AM4/11/11
to Google Web Toolkit
No breakpoints and it is slow as hell. This is some code issue as I
see that after each reload of debug , it takes longer and longer to
reload application or maybe it depends of how long it runs...

Jorn Nordahl

Oct 19, 2012, 12:52:40 PM10/19/12
Ok - I just think I figured it out: I had 6 break points set in eclipse - these break points would not be hit at all during launch - but once I removed them all (right click - remove all) then FF + Chrome launches at 'normal' development speed.


On Friday, October 19, 2012 9:43:55 AM UTC-7, Jorn Nordahl wrote:
I get this from time to time... it is sooooo slow all of a sudden and it usually happens when I am debugging away using FireFox as the browser... (we only use FF as the browser to debug). When restarting after a code change - there it is - slow as heck.... FF eventually allows me into the app - but Chrome tells me to kill the page over and over since it times out. 

I try to build, rebuild, rebuild again.... restart the box, clear out cache, run mvn clean untill I'm blue in the face..... don't know what is going on...  Then - all of a sudden - it's ok again... 

If I connect directly to the tomcat server (production mode) then everything is smooth and quick as it normally is - if I then switch over to starting the app in eclipse - then attach to the eclipsed debugger - it is slow as heck.....

Any ideas?

On Monday, August 27, 2012 1:42:00 PM UTC-7, Adam Sas wrote:

Recently I experienced the same problem. Have you figured out how to solve it?

Best regards


Nov 30, 2012, 7:30:39 AM11/30/12
I had the same problem. There was a breakpoint at Command.execute() that resulted in long waiting times (minutes) running my web application in dev mode.
Removing all the breakpoints helped. Thanks for the hint!


Jul 3, 2013, 11:14:10 AM7/3/13
Breakpoints! That's it. I've had on and off slow performance when debugging my GWT app. Removing all breakpoints snapped performance right back to normal!

excellent! thanks for posting.


Sep 4, 2013, 2:29:25 PM9/4/13
Also, for the beginners, you might have to set the log level to 'info' in the run configurations of the GWT. This is another reason why the debug on the GWT takes so long, initially when you run the application it will be set to 'All'. 

Juan Pablo Gardella

Sep 4, 2013, 2:33:18 PM9/4/13
You have to delete some temp files too.

2013/9/4 SaiP <>

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Anjali Shrivastava

Oct 23, 2013, 5:13:16 AM10/23/13
Thanks for solution, removing break points (although they were never going to be reached) helped me too in speeding up my application from super slow mode.
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