[Engine-devel] GWT Dev Mode unbearably slow in WebAdmin

[Vojtech Szocs]

----- Original Message -----
> From: "Martin Betak" <mbetak at redhat.com>
> To: "Greg Sheremeta" <gshereme at redhat.com>
> Cc: "engine-devel" <engine-devel at ovirt.org>
> Sent: Monday, February 17, 2014 12:15:47 PM
> Subject: Re: [Engine-devel] GWT Dev Mode unbearably slow in WebAdmin
> 
> Yes, this has been my developer experience since I joined the project.
> The 5-6 minute page-loads are a standard but the GWT Dev Mode gets
> progressively
> slower after each "refresh" that involves frontend recompilation. Also the
> memory
> consumption increases and after 5-th "refresh" or so I have to kill it and
> recompile the whole engine.

AFAIK classic GWT Dev Mode is slow because it does recompilation on the fly.

Not sure if related, but debugging GUI code with "gwtdev" Maven profile
(activated through "gwt-debug" Makefile target) downgrades gwt-maven-plugin
version to 2.4.0, see http://gerrit.ovirt.org/#/c/22108/ for details.

We could try several things here:

1, use gwt-maven-plugin 2.5.1 instead of 2.4.0
   in root pom.xml change
   <gwt-maven-plugin.workingRefresh.version>2.4.0</gwt-maven-plugin.workingRefresh.version>
   to
   <gwt-maven-plugin.workingRefresh.version>${gwt.version}</gwt-maven-plugin.workingRefresh.version>

2, disable GWT persistent unit cache
   in frontend/webadmin/modules/pom.xml find <artifactId>gwt-maven-plugin</artifactId>
   add <persistentunitcache>false</persistentunitcache> to <configuration>
   -or-
   make gwt-debug [usual options] DEV_EXTRA_BUILD_FLAGS="-Dgwt.persistentunitcache=false"

3, avoid using method-entry breakpoints as these are very slow [1]
   disable Firebug during initial page load

[1] https://blogs.sourceallies.com/2013/04/java-method-breakpoints-are-evil/

> 
> Any improvement to current status would be much appreciated.

I'd like to push towards GWT Super Dev Mode [2] that avoids on-the-fly
recompilation, i.e. precompiled permutation debugged directly inside
given browser.

[2] http://www.gwtproject.org/articles/superdevmode.html

(Putting above on my GWT improvement task list.)

> 
> Martin
> 
> 
> 
> ----- Original Message -----
> > From: "Greg Sheremeta" <gshereme at redhat.com>
> > To: "engine-devel" <engine-devel at ovirt.org>
> > Sent: Friday, February 14, 2014 4:50:46 PM
> > Subject: [Engine-devel] GWT Dev Mode unbearably slow in WebAdmin
> > 
> > Has anyone else noticed that GWT Dev Mode is unbearably slow for WebAdmin?
> > On
> > my machine, it's to the point where I might as well rebuild the entire
> > application for every change and not bother with Dev Mode. Pages take 4 or
> > 5
> > minutes to render. Sometimes after 5 minutes, I just give up, close
> > everything, and rebuild the app.
> > 
> > For now, I want to see if others have this issue. If we confirm that it's
> > widespread, we can discuss ways to mitigate.
> > 
> > Greg Sheremeta
> > Red Hat, Inc.
> > Sr. Software Engineer, RHEV
> > Cell: 919-807-1086
> > gshereme at redhat.com
> > _______________________________________________
> > Engine-devel mailing list
> > Engine-devel at ovirt.org
> > http://lists.ovirt.org/mailman/listinfo/engine-devel
> > 
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