GWT is slow in Development Mode

Question

I'm using Eclipse Galileo with latest GWT 2.0 version in development mode, but it runs really slow (I need to wait about a minute to open one page, but after compilation, my application works very well when I run it using Tomcat 5.5).

My code is not too heavy and I guess there is an OS-related or software inconsistency problem, because I'd this problem before, but when I reinstalled Windows Vista SP2 (I formatted my Windows drive and reinstalled it), my problem was resolved for a few days and then again it became too slow.

I didn't install any special software on my Windows machine, so I really don't know why this problem occurs. Any suggestion ?

Answer 1

First time you load the page, it loads all the necessary javacode (and the JVM). Later, each refresh of the page will only loads the changed javacode then execute the whole (I might be wrong though). So if you're closing the browser then reopening your page each time you want to see the changes you made, yes it's going to be slow. If you refresh the page each time, it SHOULD be fast (if the changes you made weren't huge).

Eclipse + GWT 2.0 is not the reason why it's slow... (by the way Shubhkarman, if I'm correct there is no GWT plugin for netbeans...)

Answer 2

I've found that the performance difference between running the GWT hosted mode in debug vs. non-debug to be large. If you're running with debug, try running without to see if that helps.

The initial page load can be slow, but once you get going just clicking refresh on my browser reloads the updated project in just a few seconds.

Answer 3

If you're using smartgwt make sure firebug or similar is disabled. That will really slow down your browser in dev mode.

And as far as NetBeans is concerned there really is a plugin for GWT called GWT4NB. But the IDE is not your problem :)

Answer 4

Delete gwt cache from temporary folders like images. rpc files..etc. than see the performance. it is one of the cause to slow in hosted mode.

Answer 5

If it has become unusually slow, but was faster previously, and you are debugging, that might be because you have a breakpoint set on a method entry. This can make things extremely slow, even if the breakpoint is not hit. Try clearing your breakpoints.

Answer 6

I had similar kind of issue and I found that it was happening because of number of break points. After reducing number of break points performance got improved.

Answer 7

Even I had the same issue with GWT. I've started testing with firefox now. first time when I ran the debug on firefox, it was slow.

I set the log level to 'info' in the runconfig > gwt tab

So, I restrated my workspace and the firefox. Then 'debug >myGWTapplication '

When you open your application on debug mode, wait for the browser plugin to connect now.

This time it does not write all the log lines in the development mode, and it is faster.

I think the firefox and the logging has made the differance. Now I do not see much lag.

Also as mentioned in the above comments, remove the debug points, i've removed all, and use then when necessary.

Edit: tried it on the IE8 - it is fast event there.