Helene
Member³
We are using a TOracleEvent object. This has turned out to be rather problematic. In the smaller installations this works fine, but when there are many users of the application on a database server, it does not work quite as well.
We had problems with this already when using DOA version 3.3, and it got even worse with 3.4.2! Previously each application user got two Oracle session in the database. That became a problem for those of our customers that have 300-400 users. Now, it turns out that each user has got AT LEAST (!) three database connections.
The oracle event is stopped by the application in certain circumstances, and is then restarted. Because of the problems we have had before, there is a system setting which decides wheter this mechanism is to be used at all. Even if the setting was false, the program did start the event and soon after stop it. With 3.4.2 this caused the three sessions to continue their presences, while the same source code with 3.3.1 would cause only one session/user in these installations.
Using the Oracle Monitor I can see that the third session appears when the oracleevent is stopped. There is one OracleEvent_DuplicateSession and one OracleEvent_StopSession. (By the way, I would like to be able to see in the Monitor wheter a session is connected or not - something like the red cross next to objects that have been freed).
I have not been able to reproduce in the test environment the situation in which a user has got more than three sessions. In development we are using Windows NT, while these users have Windows 95 on their clients, however I doubt that this could be related to this problem ?
Why are there now three database sessions in this situation? Are we doing something wrong, or is there any way we can prevent this?
I would really like to know what experience other people have had when using the TOracleEvent component. Is it much used? Do you have any problems with it?
Helene
[This message has been edited by helene (edited 27 October 2000).]
We had problems with this already when using DOA version 3.3, and it got even worse with 3.4.2! Previously each application user got two Oracle session in the database. That became a problem for those of our customers that have 300-400 users. Now, it turns out that each user has got AT LEAST (!) three database connections.
The oracle event is stopped by the application in certain circumstances, and is then restarted. Because of the problems we have had before, there is a system setting which decides wheter this mechanism is to be used at all. Even if the setting was false, the program did start the event and soon after stop it. With 3.4.2 this caused the three sessions to continue their presences, while the same source code with 3.3.1 would cause only one session/user in these installations.
Using the Oracle Monitor I can see that the third session appears when the oracleevent is stopped. There is one OracleEvent_DuplicateSession and one OracleEvent_StopSession. (By the way, I would like to be able to see in the Monitor wheter a session is connected or not - something like the red cross next to objects that have been freed).
I have not been able to reproduce in the test environment the situation in which a user has got more than three sessions. In development we are using Windows NT, while these users have Windows 95 on their clients, however I doubt that this could be related to this problem ?
Why are there now three database sessions in this situation? Are we doing something wrong, or is there any way we can prevent this?
I would really like to know what experience other people have had when using the TOracleEvent component. Is it much used? Do you have any problems with it?
Helene
[This message has been edited by helene (edited 27 October 2000).]
