Re: [OpenMap Users] RPF Memory Issues with CIB

From: Don Dietrick <dietrick_at_bbn.com>
Date: Thu, 4 May 2006 09:55:21 -0400

Hi Chris,

There are a couple of things you can do. The RpfLayer has two caches
- one for frames read off of the disk (each file is about 273k), and
one for subframe images decompressed from the frame information. The
default number of frames held in the frame cache is 4, and the
default number of subframes (256x256 pixel images) is 40. You can
adjust these depending on the I/O and CPU loads your architecture can
afford. Also, there is a default setting that allows the
OMScalingRasters used by the RpfLayer to scale their images based on
map projection scale. If you set that to false, the OMScalingRaster
won't maintain two copies of the image (the original one from the
cache and/or held by the OMScalingRaster in case the cache is dumped,
and the scaled version being rendered), and you might see some
savings there, too.

You can make these settings in the properties file, there are details
in the javadocs. I think there are programmatic settings, too.

The amount of memory used depends on the cache sizes and the map
pixel size - the subframe image sizes are the same regardless of
chart scale or image resolution, and the number of subframe images
needed depends entirely on map pixel size.

Hope this helps,

Don

On May 3, 2006, at 11:27 AM, Chris Paul wrote:

> Hi Don,
>
> The maps are being generated in two scenarios. The first is a thick
> client
> application which generates MapBeans in a standard Swing component.
> The
> second is a JBoss server deployment, which is accessed by the
> client using a
> web browser.
>
> We're having problems in both scenarios where each map displaying CIB
> imagery will take up about 400MB of heap space. This causes the app/
> server
> to quickly run out of memory. This is a concern because the server
> will
> obviously be aimed at hosting several users, with the potential of
> generating several maps.
>
> Thanks in advance,
> Chris
>
> -----Original Message-----
> From: owner-openmap-users_at_bbn.com [mailto:owner-openmap-
> users_at_bbn.com] On
> Behalf Of Don Dietrick
> Sent: Wednesday, May 03, 2006 5:34 AM
> To: Chris Paul
> Cc: openmap-users_at_bbn.com
> Subject: Re: [OpenMap Users] RPF Memory Issues with CIB
>
> Hi Chris,
>
> Can you describe your architecture a little more? What's running on
> your client, and what's running on your server?
>
> - Don
>
>
> On May 1, 2006, at 11:57 AM, Chris Paul wrote:
>
>> Hi all,
>>
>>
>>
>> This is my first email to the list, so please be gentle.
>>
>>
>>
>> I'd like to get some opinions on a memory issue we've run into.
>> When working with satellite imagery and CADRG projections, our
>> server/application frequently runs out of memory. This occurs when
>> a user zooms down into CIB range on several different maps, or when
>> several users zoom into CIB range on different maps. A new RPF
>> layer is created for each user or map display and each of these
>> layers is necessarily very large. We'd like to figure out a way to
>> reduce the memory footprint of the RPF layer (which typically
>> allocates about 400MB). Are there settings available to lower this
>> number? I have 2GB of memory, and have increased my heap size to
>> 1GB, which simply delays the problem, allowing me to get 3-4 maps
>> going, instead of 1-2 (at 512MB).
>>
>>
>>
>> Any other ideas for addressing this issue?
>>
>>
>>
>> (This is similar to the following issues on the mailing list archive:
>>
>> http://openmap.bbn.com/mailArchives/openmap-users/2002-10/1170.html
>>
>> http://openmap.bbn.com/mailArchives/openmap-users/2004-07/3000.html)
>>
>>
>>
>> Thanks in advance,
>>
>> Chris Paul
>>
>> Intelligent Software Solutions (ISS)
>>
>>
>
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Received on Thu May 04 2006 - 09:57:13 EDT

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