Sybase dbdata9.dll blocking threads and hanging IIS

Question

Apologies if this has already been asked and solved but through numerous searches and lost hair we're getting to the end of our tether!

We have a web server running web services through IIS 6. These web services talk to our database server which has both Sybase SQL Anywhere 9 databases and MS SQL databases. Since a release at the start of December we have been experiencing IIS hanging and can only be made responsive again by re-cycling the default App Pool. Through many investigations, memory dumps and code changes everything seems to be pointing to the Sybase database that is being the culprit. This is backed up by the fact that it is now being accessed a lot more since this release.

We have tried pretty much everything possible but every memory dump we have done when the web server hangs contains the information that "Detected possible blocking or leaked critical section" and that it relates to "dbdata9" which is the main dll used for the Sybase database.

We found that we had not got the latest Sybase .Net Provider and have updated these on the server and in the code but we are still getting these occasional hangs! The latest message that has been reported in the memory dumps a few times is:

"Detected possible blocking or leaked critical section at dbdata9!AsaTransaction_SendTransactionCookie+46640 owned by thread #"

I'm running out of ideas how to get around this and if anyone has any good suggestions on how to progress with this it'd be a great help!

If you need any more information just ask and I will provide.

Thanks in advance.

Answer 1

For anyone who wants to know it seems that the problem was with Sybase itself and was fixed in a later version of its software. Once we updated the dlls to the latest version it seems to have cleared our issues. If anyone wants any more information on this please feel free to ask.