SQLUM Thread Safety Bug

Hi, 8)

The sqlum code in file k2usermanager.vb
uses a "Private arrUserNames As New ArrayList".

This is not thread safe and as the number of exported destination queues increase so does the chance of a threads overwriting each others variables. I noticed this in early tests when using the SQLUM.

Example:
The "Public Function ResolveQueue" is being called by the server periodically in a threaded manner. BUT Because arrUserNames is not thread safe 2 different calls can corrupt each others queue resolution. I.e. the destination queues WILL and DO resolve sometimes incorrectly.
After we have exceeded 30 destination queues (say 5 processes with 6 queues in each) it was happening all the time. Before that it was happening only rarely and was impossible to track the bug.

Remedy. I have fixed this problem by sending the arrUserNames variable in the function header as input variables in k2usermanager.vb and removed the private class variable arrUserNames in the top of the file.

Note that this problem is not exclusive to destination queues.

If you are using SQLUM I strongly recommend you to fix it before you use it in a production environment.

Regards,
Gabor Barla-Szabo :P
Fourier Approach
fourier.co.za