Release 10.1A: OpenEdge Development:
Debugging and Troubleshooting

Compatibility issues

Changes in the Debugger over time have lead to certain incompatibilities when debugging in a distributed environment when a client and an AppServer are running on different software releases.

The client and AppServer use a protocol to communicate during debugging. There have been changes to this protocol such that an AppServer running on an earlier or later release cannot communicate effectively with the client in some configurations.

Added features in a later release introduce new commands to support these feature requests. An AppServer running on an earlier release cannot service the new feature requests because it does not recognize the commands introduced in the later release.

The Debugger reconciles release discrepancies sufficiently in some cases to continue executing, and in others, to provide feedback on why it cannot continue. Table 1–1 summarizes what happens when attempting client/AppServer debugging with different software releases.

Table 1–1: The Debugger and mixed client/AppServer releases 

Client	AppServer	Results
9.1D05/06/07	9.1D05/06/07	The client and AppServer must be running on identical releases, that is, 9.1D05 to 9.1D05, 9.1D06 to 9.1D06, and 9.1D07 to 9.1D07 to debug successfully; otherwise, results are unpredictable.
9.1D08	9.1D07 or earlier	Incompatible protocols prevent the client and AppServer from communicating. The Debugger displays an error message to this effect; the procedure executes without debugging.
10.0A	9.1D07 or earlier	Incompatible protocols prevent the client and AppServer from communicating. The Debugger displays an error message to this effect; the procedure executes without debugging.
10.0A and later	9.1D08 and later	The client protocol adapts to the protocol of the AppServer. Debugging proceeds as expected. When debugging on a 9.1D08 AppServer, feature requests dependent on the later release will not execute. For example, conditional breakpoints fire, without first testing the condition; error breakpoints do not fire at all. Other cases might result in an error message from the AppServer because it does not recognize a command new to the later release.
9.1D08	10.0A and later	The client protocol adapts to the protocol of the AppServer for debugging purposes, but cannot take advantage of the features in the later release.