Wierd problem during logon

[Clayton Arends]

I have a curious issue which maybe you might be able to shed some light on.

I have a product built using C++Builder 5 that uses DOA 3.4.5.0. I have a client who has upgraded from build 300 to build 314. The problem is that the client used to be able to logon using build 300 but can no longer logon using build 314. The following error message is returned during logon:

"TNS:unable to connect to destination"

I cannot think of any significant changes that were made in regards to how DOA is accessed. Also, we have many other clients using 314 without any problem. If this client uninstalls 314 and reinstalls 300 the logon works fine again.

I am going to continue to try to find the cause for this in our code but seeing as how I am using a simple Logon dialog at that point all of the work is performed in DOA. Obviously *something* is different but I am at the starting line at diagnosing this right now.

The client uses Oracle 8.1.6 and encrypted SQL*Net.

Thanks,

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Clayton Arends
Sr. Software Developer
Evisions, Inc.http://evisions.com

 

[Marco Kalter]

If this is a multi-threaded application where each thread has its own TOracleSession instance, and threads connect to the Oracle Server simultaneously, you may be running into a Net8 bug. To circumvent it, you can either use a CriticalSection to prevent simultaneous logon operations, or you can upgrade to 3.4.6, which implements this if TOracleSession.ThreadSafe = True.

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Marco Kalter
Allround Automations

 

[Clayton Arends]

Thanks Marco. This is a multi-threaded application but all of the Oracle access is handled by the main application thread. We do not have multiple logons.

The user has since installed our app on another system and it doesn't receive the logon error. So, I am going to assume a bad Oracle installation (which is not uncommon) and leave it at that. Still, it's odd that both builds behave differently and they both use 3.4.5.

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Clayton Arends
Sr. Software Developer
Evisions, Inc.http://evisions.com