A hard one! DCOM/MTS

[TheWarnster]

O.K. here is the scenario.

I have a client/server based application that uses a VB6 front end a VB6 ActiveX DLL in MTS as a buisness layer and a SQL 7 database using Stored procedures to access the data.

This all works fine on a local area network.

We are currently trying to roll this out on a WAN. the WAN uses ISDN lines and routers to route the machines on to the LAN.

When trying to run the application. it generates an error on the Buisness layer/MTS server.

The error is reported in the Event Viewer.

The error relates to the class that calls the stored procedure via an ODBC DSN. The strange things is the error is saying that one of the parameters for the stored procedure, passed by the client, is not there.

The parameters are passed by the client via a ADOR recordset. Its as if the recordset is empty when it gets to the server although it is deffinetly populated before the remote call.

Any help would be appreciated!

[Bill Crawley]

This is indeed a strange one. First off I'd check permissions. Make sure you are also checking the ADO error collection since this may also give an indication.

I'd also drop ODBC and use the native data provider, since it may be that the ODBC layer is causing the problem. If you are committed to using ODBC make sure all machines have the same version of the ODBC Driver (i.e. has the remote machine got the same version as the local machine where it works).

Design issue - Since your going WAN I'd also introduce MSMQ if I were you since this handles passing the data from one machine to another and ensures delivery. THis may make the system appear to work faster to the user and also make the app scale better. It may also help solve the problem you have.

[TheWarnster]

Many Thanks for the info,

I had already sorted out the problem though!!

The remote machines had an old version of MDAC on them and this was causing the problem.

All works fine now!!