= !MapGuide RFC 19 - Concurrent FDO provider connections =

This page contains a change request (RFC) for the !MapGuide Open Source project.  
More !MapGuide RFCs can be found on the [wiki:MapGuideRfcs RFCs] page.


== Status == 
 
||RFC Template Version||(1.0)|| 
||Submission Date||Apr 13, 2007||
||Last Modified||Bruce Dechant [[Timestamp]]||
||Author||Bruce Dechant||
||RFC Status||Draft||
||Implementation Status||Pending||
||Proposed Milestone||1.2||
||Assigned PSC guide(s)||Robert Bray||
||'''Voting History'''||||
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||+0||||
||-0||||
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== Overview ==

The purpose of this RFC is to support a way to limit the # of concurrent FDO connections to a specific provider. By allowing for a limit to the # of concurrent FDO connections the server can support single threaded providers and any provider that has a limit on the # of client connections (ie: Oracle, etc...).

== Motivation ==

Currently, the server only supports FDO providers that support a thread-per-connection or better thread model. Although not ideal there is no support for single-threaded providers or for restriction the # of concurrent FDO connections. This needs to be addressed.

== Proposed Solution ==

The server will be modified to allow for a way to specify a default maximum # of concurrent FDO provider connections and for a way to specify a specific # of concurrent FDO provider connections for a specific provider.

{{{
# DataConnectionMaxConcurrent          Default # of allowed FDO connections per provider
#                                      0 < Value <= 100
# DataConnectionMaxConcurrentCustom    Custom # of allowed FDO connections for specified provider
#                                      0 <= Value <= 1024
#                                      Example: OSGeo.SDF:10,OSGeo.SHP:10
DataConnectionMaxConcurrent        = 20
DataConnectionMaxConcurrentCustom  = OSGeo.SDF:10
}}}

The server will also check the thread model supported by the underlying FDO provider and if it is single-threaded then the maximum # of concurrent FDO provider connections will be limited to 1 regardless of the above settings.

== Implications ==



== Test Plan ==

Test concurrent access to various FDO providers.
Test single threaded FDO provider, example GDAL.

== Funding/Resources ==

Autodesk to provide resources / funding.