We have a powerbuilder module in PB 12.6 Classic which runs as multiple parallel background tasks.
While this runs efficiently on Windows 7 Pro - when we moved it to Windows Server 2012 R2 - it ran much slower regardless of the performance of the servers and database it was running with.
We seemed to be throttled at about 8 background tasks - adding more tasks just slowed down the overall throughput. And the CPU resource never got past 20% no matter what we threw at it - a huge bottleneck
We spent weeks investigating the OS configurations, Database tuning, Fairshare Scheduling, BIOS adjustments - all to no avail.
I noticed that our tasks were gaining memory size as they ran - and we investigated memory leaks of various types.
Talking with SAP support about a separate issue, I happened to bring up the memory issue, the tech mentioned a case about how datastores were using windows handles and that it could be turned off. He send me the following.
The following url is to the article that explains the issue with datastores and handles.
http://search.sybase.com/kbx/solvedcases?id_number=11689586
The following is what you would put in the pb.ini file.
[DataStore Behavior]
UseHwnd=no
As the article mentions, there is no known side effect to turning off Windows Handles on Datastores.
This turned out to be a miracle cure for the throughput problem with our application. Now we can run 24 tasks or more at 4-5 times the throughput utilizing 80-100% of the CPU if we need it.
I see various posts about unexplained slow performance when moving non-visual background apps to Windows Server 2012 - perhaps this is the cure.
As this is not a well known fix I hope everyone in the community can share the discovery. Also I feel that Engineering should have fixed the problem rather than issue an obscure getaround.
Glenn Barber