BSOD SESSION_HAS_VALID_POOL_ON_EXIT (ab)

Currently we get SESSION_HAS_VALID_POOL_ON_EXIT (ab) BSODs regularly on our Windows Server 2012 servers. These servers are used as XenApp servers and therefore a BSOD on such a server is pain in the ass when you have 50 users or even more working on such a server.

Finally Microsoft confirmed that this is a bug and they are now working on a fix. I will update this post as soon as I get a hotfix that resolves the issue.

The windbg output looks as follow:

SESSION_HAS_VALID_POOL_ON_EXIT (ab)

SESSION_HAS_VALID_POOL_ON_EXIT (ab)

Update 05.09.14: I got a private hotfix from Microsoft that definitively fixes the issue. I informed the Microsoft engineer today that they can start to initiate the process to release a public hotfix. We have seen the BSOD 1-2 times per day, and it completely disappeared since we applied the hotfix. There seems to be another bug we discovered by another BSOD that Microsoft is analyzing, but finally no AB BSOD!

Update 11.02.15: The fix has now been released for public:
More Information: https://support.microsoft.com/kb/3036220
Download: http://www.microsoft.com/en-us/download/confirmation.aspx?id=45710

ICA Session Performance counters missing

In case you’re missing the ICA Session performance counters in perfmon, run that command for XenApp/XenDesktop 7.x:

regsvr32 C:\Program files (x86)\Citrix\System32\icaperf.dll

Change the path of the dll according to your install folder, the one above is default. This will register the dll that brings back the counters:

ICASession-PerfCounters

I’m not sure why they suddenly disappeared on my servers, but that might be a side-effect from a Citrix Hotfix.
The performance counters are very useful when troubleshooting issues, especially on WAN connections. You can monitor the network latency and bandwidth used from your XenApp server to all the end clients of the users connected to the server. Also HDX Monitor gets the data from these counters.

Update 08.09.2014: Citrix provided a hotfix that brings the performance counters back: http://support.citrix.com/article/CTX141330