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 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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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.