MapGuide RFC 19 - Client/Web/Server Compatibility

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	March 7, 2007
Last Modified	Bruce Dechant Timestamp
Author	Bruce Dechant
RFC Status	draft
Implementation Status	pending
Proposed Milestone	1.2
Assigned PSC guide(s)	(when determined)
Voting History	March 7, 2007
+1
+0
-0
-1

Overview

WORK IN PROGRESS WORK IN PROGRESS WORK IN PROGRESS WORK IN PROGRESS WORK IN PROGRESS

There is currently no mechanism in place to allow older clients to communicate with a newer MapGuide web tier or server and vice versa. This needs to be addressed in order to allow easier upgrade paths for end-users.

Motivation

There needs to be someway for a client to be able to identify the version it is so that the web tier and server can properly communicate with it. This proposal hopes to add some form of forwards/backwards compatibility to MapGuide in order to solve this.

Proposed Solution

Client Changes:

Clients like MapGuide Studio will need to add the following HTTP parameter:

CVER=MajorVersion.MinorVersion

Example:

CVER=1.2

The web tier and server will be able to use this information in order to do the operation that uses that version. This will allow schema changes to take place and for multiple versions of the schema to be supported because the client tells us what version it is and therefore what schema version it supports.

This solution only helps with newer releases of MapGuide as existing releases will not contain this forwards/backwards compatibility logic. However, the web tier/server will assume that if a CVER is not included in the HTTP operation that it is an older client and to use the oldest supported version of the operation.

The web tier and server must always be the same version because there could be changes to the TCP/IP protocol between them that could cause them to no longer comuunicate. There is already logic in place to identify this i

Implications

The web tier and server will now be able to recognize clients and will be able to give the proper response, as long as, they support the version of the client.

Test Plan

Simulate old client and new client operations to the web tier/server.

Funding/Resources

Autodesk to provide resources / funding.