Flemming, This sounds nearly identical to the -709 I see on Windows 2000 Server. I even posted a Win32 testing program to re-create it, and Thomas @ SAP did reproduce the problem.
In our case, it was blamed on a socket issue with the TCP/IP stack of Windows 2000. If you use the same TCP/IP socket to respond to all requests, you can get these. Solution is to not use the same socket, but Thomas indicated this would require major changes to the ODBC driver and XServer interfaces. We were considering moving our servers to Linux to resolve the problem. I am very anxious to see if anyone has done stress testing. The key is lots and lots of: open, small transaction, close. This is very common in web applications. You and I both complained of this back in early November 2002 timeframe. Going to 7.4 has not made any improvement for us. Stephen Gutknecht -----Original Message----- From: Daniel Dittmar [mailto:[EMAIL PROTECTED] Sent: Tuesday, February 11, 2003 3:55 PM To: [EMAIL PROTECTED] Subject: Re: Unable to connect to 7.3.0 DB under load Flemming Frandsen wrote: > I have just been running a stress test on a webapplication that uses SAP > DB (version: X32|LINUX 7.3.0 Build 029-000-087-800), I use DBD:ODBC > compiled against the sapdb driver and the database seemed to keep up > nicely except when it had been running for a while then it started to say: > > [SAP AG][LIBSQLOD SO][SAP DB]Unable to connect to data source;-709 > CONNECT: (cannot create communication semaphore). (SQL-08001)(DBD: > db_login/SQLConnect err=-1) > > ... during connect, it did not work retrying the operation 2 more times. > > There were plenty of room until hitting the roof of 200 connections > (there were about 30). > > Maybe the sapdb client leaks some type or resource? > > Has this been fixed in 7.4 and how dangerous is it to upgrade from 7.3? > Perhaps watching the number of semaphores in use (http://sapdb.2scale.net/moin.cgi/DiagnosingSharedResources) sheds some light on this. Maybe it's a bug in the client libraries, maybe the sessions aren't released properly (at whatever level) and have to wait for a timeout. Daniel Dittmar -- Daniel Dittmar SAP DB, SAP Labs Berlin [EMAIL PROTECTED] http://www.sapdb.org _______________________________________________ sapdb.general mailing list [EMAIL PROTECTED] http://listserv.sap.com/mailman/listinfo/sapdb.general
