[mapguide-users] ODBC Point features failure

Mon Jul 9 16:19:51 EDT 2007

We’ve never supported or tested with the native driver that I am aware of so I can’t help on that front.

I’m not sure how to tackle this since we don’t know the conditions to reproduce the original communication link failure error.

The following MS article may yield something:

http://support.microsoft.com/kb/827422/en-us

Are you using IP address or name to connect to the server? Is the port the default 1433? I assume your SQL Server is configured to listen on TCP/IP.

What version of MDAC is on your server? It’s supposed to be 2.8 in 2003.

If the timeout is really only a minute then that doesn’t match any MapGuide timeouts that I’m aware of.

Dave

From: mapguide-users-bounces at lists.osgeo.org [mailto:mapguide-users-bounces at lists.osgeo.org] On Behalf Of IElsinga at fac.bm
Sent: Monday, July 09, 2007 7:17 AM
To: MapGuide Users Mail List
Subject: RE: [mapguide-users] ODBC Point features failure

Hi Dave, 

I tried turning off the ODBC connection pooling - this has no affect - still times out after about 1 minute with that error message.    I will experiment with the various timeouts in mapguide and see if that helps.   

Meanwhile,   I am using the SQL Server ODBC driver, not the Native SQL Server driver - the latter cannot be used because of a problem identified by someone else recently - the Native driver has a problem reading SQL Server tables.   I was thinking that the Native driver may solve this issue, but it doesn't work at all.  Here's the error: 

<2007-07-06T16:37:40>                         Administrator 
 Error: An exception occurred in FDO component. 
        Invalid length 0 for column type VARCHAR, must be &gt; 0 
 StackTrace: 
  - MgFeatureServiceHandler.ProcessOperation line 83 file c:\build_bond_area\mapguide_open_source_v1.2\build_18.1\mgdev\server\src\services\feature\FeatureServiceHandler.cpp 
  - MgOpDescribeSchemaAsXml.Execute line 107 file c:\build_bond_area\mapguide_open_source_v1.2\build_18.1\mgdev\server\src\services\feature\OpDescribeSchemaAsXml.cpp 
  - MgServerDescribeSchema.DescribeSchema line 500 file c:\build_bond_area\mapguide_open_source_v1.2\build_18.1\mgdev\server\src\services\feature\ServerDescribeSchema.cpp 
  - MgServerDescribeSchema.ExecuteDescribeSchema line 173 file c:\build_bond_area\mapguide_open_source_v1.2\build_18.1\mgdev\server\src\services\feature\ServerDescribeSchema.cpp        An exception occurred in FDO component. 
Invalid length 0 for column type VARCHAR, must be &gt; 0 

This one does seem to be a mapguide bug - there are no tables in our schema which have a varchar length less than 10 - it seems not to be able to read the varchar type properly.   

Any ideas on this one? 

Thanks 

Ian Elsinga

"Dave Wilson" <dave.wilson at autodesk.com> 
Sent by: mapguide-users-bounces at lists.osgeo.org 

07/06/2007 12:50 PM 

Please respond to
MapGuide Users Mail List <mapguide-users at lists.osgeo.org>

To

"MapGuide Users Mail List" <mapguide-users at lists.osgeo.org> 

cc

Subject

RE: [mapguide-users] ODBC Point features failure

By default there are a series of timeouts that are set that could be affecting what you are seeing. Adjusting the timeouts completely depends on the behavior of the users. 

For example as a developer working on a map you may want to significantly increase the timeout settings to allow connections to last for 20 min or more whereas a user on the production server may spend no more than 5 or 10 min querying a map so holding connections for too long is a waste or can potentially not free up resources for other users. 

Most of the default settings hold a session for about 20 min. So after you let your map sit for 20 min you will have to refresh it. However below the main timeout settings there is Connection Pooling taking place within FDO. These connections are held for 10 min (600 seconds) and then released. You may want to try and up this to 20 min to match the other timeouts. However in testing we have never seen the link failure error that I am aware of. 

A communication link failure seems more like something external to FDO has dropped the connection rather than FDO dropping the connection. FDO is trying to use a connection that is no longer valid for some reason. Is there a proxy server or firewall or router in between your MapGuide server and your database server that could be dropping the connection? I’ve done some Google searches and one possibility is that your DSN has connection pooling enabled and it may be that the connection is dropped by SQLServer by the time you try to reuse it. It’s not clear yet if it’s actually a MapGuide bug. 

The Google searches weren’t very informative. You might try to search msdn instead. 

Dave 

From: mapguide-users-bounces at lists.osgeo.org [mailto:mapguide-users-bounces at lists.osgeo.org] On Behalf Of IElsinga at fac.bm
Sent: Thursday, July 05, 2007 11:05 AM
To: MapGuide Users Mail List
Subject: RE: [mapguide-users] ODBC Point features failure 

Hi Dave, thanks for the responses... 

I didn't know about the error log - there are indeed error messages like the following: 

<2007-07-05T13:54:45>                         fac 
Error: Failed to stylize layer: Points 
       An exception occurred in FDO component. 
       RDBMS: [Microsoft][ODBC SQL Server Driver]Communication link failure 
StackTrace: 
 - MgStylizationUtil.StylizeLayers line 923 file c:\build_bond_area\mapguide_open_source_v1.2\build_18.1\mgdev\server\src\services\mapping\StylizationUtil.cpp        Failed to stylize layer: Points 
An exception occurred in FDO component. 
RDBMS: [Microsoft][ODBC SQL Server Driver]Communication link failure 

Why would there be a Communications link failure?  We have lots of processes which communicate to that particular database continually.   It seems that something inside the FDO provider times out and it thinks it can no longer access SQL Server.   

If I restart the mapguide service and re-open the site, it initially works.  If I let it just sit there for a few minutes, without doing any zooming or panning or clicking, then when I try to zoom after that, the points disappear - and that error message above is in the error log.   So it seems that something in the FDO provider is timing out - it is allowing the connection to timeout perhaps and it doesn't re-establish it? 

Thanks for your help, 

Ian Elsinga

"Dave Wilson" <dave.wilson at autodesk.com> 
Sent by: mapguide-users-bounces at lists.osgeo.org 

07/05/2007 11:36 AM 

Please respond to
MapGuide Users Mail List <mapguide-users at lists.osgeo.org>

To

"MapGuide Users Mail List" <mapguide-users at lists.osgeo.org> 

cc

Subject

RE: [mapguide-users] ODBC Point features failure

Are there any errors logged in the server error log? It seems to me something is causing the provider to die? Usually there is at least 1 error logged before something like this can happen. 

What coordinate system is your data in and what coordinate system is your map in? 

Have you tried using the DWF Viewer/Autodesk Design Review? I’m curious if it’s the data or something in the viewer behavior. 

Regards, 
Dave 

"Dave Wilson" <dave.wilson at autodesk.com> 
Sent by: mapguide-users-bounces at lists.osgeo.org 

07/04/2007 06:47 PM 

Please respond to
MapGuide Users Mail List <mapguide-users at lists.osgeo.org>

To

"MapGuide Users Mail List" <mapguide-users at lists.osgeo.org> 

cc

Subject

RE: [mapguide-users] ODBC Point features failure

In house testing with a feature source containing almost 10,000 features appears to work fine. 

How much memory on your system? What is the OS? Do you have properties selected on your layer? How many other layers are in your map? 

Regards, 
Dave 

From: mapguide-users-bounces at lists.osgeo.org [mailto:mapguide-users-bounces at lists.osgeo.org] On Behalf Of IElsinga at fac.bm
Sent: Wednesday, July 04, 2007 10:33 AM
To: mapguide-users at lists.osgeo.org
Subject: [mapguide-users] ODBC Point features failure 

I am using MGOS 1.2 RC2 and am experiencing a problem with an ODBC connected to SQL Server point source.    Points are displayed initially, but then eventually they are not displayed any longer.  Opening a new web browser does not help.  The only way I can get them to come back is to restart the MapGuide windows service - then the points will come back - for a few minutes of interaction.   

I am bringing back 1000 points from a SQL Server database.    This behaviour was the same in 1.2 RC1. 

This will obviously make mapguide unusable for our purposes - is there a problem with the ODBC FDO?   

I will be grateful for any assistance!   

Ian Elsinga_______________________________________________
mapguide-users mailing list
mapguide-users at lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/mapguide-users
_______________________________________________
mapguide-users mailing list
mapguide-users at lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/mapguide-users_______________________________________________
mapguide-users mailing list
mapguide-users at lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/mapguide-users_______________________________________________
mapguide-users mailing list
mapguide-users at lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/mapguide-users

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.osgeo.org/pipermail/mapguide-users/attachments/20070709/b70551ff/attachment.html