A couple quick answers...

There really should not be a memory leak :-) Have you tested with a
profiler to see what is holding onto the memory? I know we can control
how many rows the jdbc driver gulps down at a time (default is 200 or
something). Is it a constant memory leak - or does it get worse over
time ... each pan or zoom etc should issue a new request; so the
metric of 6 megs per layer does not make much sense to me right now.

Upgrading to 1.2 should not help or hinder this issue; but until we
find the cause I cannot tell for sure.

The best way to plan for a stable 1.2 release is to help out in the
code sprint Jesse is planning. This will both give you a feel for
where the code base is at; and give you a first hand impression of
where we are at. I am doing a tutorial around uDig 1.2 at FOSS4G this
year; and I have a set feature list in mind - however I am willing to
cut scope to get a release out so your volunteer efforts would be
helpful :-)

Jody




On Wed, Jun 3, 2009 at 5:57 AM, David Middlecamp
<[email protected]> wrote:
> Hi Everybody,
>
>  Having done some research, it seemed like the time to ask the
> experts...  (it's a development question, really)
>
> I'm currently developing a application based on the uDig 1.1.1 sdk, and
> I think I've spotted a memory leak during some recent performance testing.
> The strange part is that it's such a typical use case that I'm
> sure someone must have spotted it ages ago.  I tried to find references
> to it across the archives (the last 6 months), the bug tracking for
> Geotools, and the bug tracking for uDig over the last five years, and I
> think I've found a few candidates (about 10 known issues), but I'm not
> sure if they apply.
>
> Here's our test scenario:
> I tested this across uDig 1.1.1, and uDig 1.2-M4, and our application
> based on 1.1.1
> Our test map had 2 shapefile layers (small shapefiles, unprojected)
> And 2 postgis layers, a basic table, no filters, etc.
>
> only step:  Cause the map to redraw (and, in theory, query the
> datastore)...  (panning, zooming, hitting refresh, etc)  (this can't
> be right, right?)
>
> I rigged up our application to output actual used heap space, but for
> uDig 1.1.1, and 1.2-M4 I used the Task Manager...
>
>  During my tests, doing the same number of refreshes, etc, both uDig
> 1.1.1, and my application (no surprise), leaked about 6 megs per postgis
> layer in the span of a few minutes.  I know the vm heap size in the
> task manager doesn't reflect the actual memory used, so it's not
> helpful when trying to diagnose a leak like this.
> I would really like to upgrade to 1.2, but without actually heavily
> modifying my application to work with 1.2, I can't tell if this
> particular issue was fixed or not.
>
>  We're really excited here to use the fixes and new features in the 1.2
> release, but is it too soon to merge 1.2-M4 into our production code?
> (Is there a date in mind for a 1.2 stable release?)  Also what uDig
> best practices have people used to minimize their footprint,
> and increase stability over long running times?
>
> Thanks,
> David
>
>
> _______________________________________________
> User-friendly Desktop Internet GIS (uDig)
> http://udig.refractions.net
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>
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