[mapguide-users] Advice on the use of 300 DWF layers

[lucvanlinden]

Hi All


We are investigating the use of DWF layers from DWF files in MapGuide OS
2.6.

These 300 DWF files are generated from 300 DWG files using AutoCAD MAP 3D
via export to DWF with assigned CS from Modelspace while setting the DPI
appropriately.
The content of these files are all autocad dimension objects for a long
network.
1 single DWG file corresponds actually to a “grid” of 4500 meter by 5000
meter.
Size of the DWF files ranges from 190 kb  to 4 kb.

We tested with a couple of DWF's and they worked really well, also thanks to
the use of Maestro!

The loading of the DWF works quit well with the Load Procedure from Maestro.
300 DWF source files, each containing  a single (autocad) layer of dimension
objects, resulting in 300 data DWF drawing Sources, from which 300 (DWF)
Layer definitions are generated.
BTW, all names are unique.
We added a folder to our map definition which contains those 300 layers.

Although to be able to save the map definition in Maestro, we already had to
increase the
SessionRepositoriesLimit           = 200
to 1000
to avoid having the Error : DBEnv::open: DB_RUNRECOVERY
as mentioned here:

http://forums.autodesk.com/t5/infrastructure-map-server/error-dbenv-open-db-runrecovery/td-p/3126680

Now, once the map is consumed through the flex web layout/Fusion the system
is not capable of returning a map at all given again the error in the
browser:

An exception occurred in DB component. DbEnv::txn_begin: DB_RUNRECOVERY:
Fatal error, run database recovery.

We have to admit, in the initial test with only 5 DWFs we managed to set the
maxscale to 1000 through the XML editor.
I believe here is a small bug in the Maestro interface where the Maxscale is
never inserted into the Layer definition on save, while it does when using
the XML editor.

This brings some questions to the surface on the use or usability of (a
large number of) DWFs in such a context:

1. What would be the quickest way  to include the Maxscale values in the XML
Layer definitions for those 300 DWF layers (without doing this manually)?

2. Would it help the server to avoid "rendering all DWF files on the initial
mapload (given the default maxscale value of infinite)?
With other words, is Mapguide somehow spatially indexing the bounds of the
DWF files and will it only access the appropriate content that it needs
(given a reasonable scale factor)?
A bit like or comparable to principles of the RasterWorkshop (Loading,
creating the ric file ) of Mapguide 6.5?

3. In addition, the CS of the DWF is different from the Pseudo Mercator used
by the Fusion web Layout.
For the initial test we did not had any issue with performance (also I guess
given the maxscale) while the content was transformed consistently on the
fly.
Would it be necessary to have the DWF files pre transformed in the Pseudo
Mercator? Would that be necessary even if MapGuide would have such a RIC
principle in place? 

3. Is there any other advice in using a large number of such files/layers in
MapGuide?

4. Are there any other settings we have to (re)set in the ini files?

5. It seems that restarting the service MAPGUIDE OS takes care of the
DB_RunRecovery stuff or are there any specific actions and or tricks we have
to apply in order to “reset” the server?

Thanks in advance for any input (even if it was on one of the questions
only)

Luc




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