nVision hanging problem

By Larry Grey • August 1, 2005

Just saw the following questionon ITTOOLBOX.COM

It’s an interesting problem, and is completely related to how nVision and excel work in conjunction with each other.

Here is background information on the problem:

When nVision runs on the process scheduler, two processes are launched, PSNVS.EXE and EXCEL.EXE. Sometimes, one of the processes crashes or hangs, and the process scheduler doesn’t know how to manage both of them (it only knows about the one it directly launched).

The person posting the question already found the way to clean it up: look on the process scheduler server that is having the problems, and then looking at task manager to see if there’s the same number of PSNVS.EXE and Excel.EXE processes. Then, killing the one that’s out there.Usually, what causes this problem is contention in excel. It’s not truly multi-threaded, and so when it is hung by one nVision instance, others have problems launching.

For customers upgrading from release 7.5, nVision’s architecture was different (and the scheduler would not run more than 1 nVision report at a time). This may explain why the problem only manifested itself after an upgrade.

We did a lot of testing after numerous customer complaints and found that running too many nVision reports in parallel on the same serveris what often causes the hanging to occur (again, related to multithreading issues in Excel). This is also why in PeopleTools 8.2x, it is not recommended to run more than 3 nVision reports on a process scheduler instance at the same time.

PeopleTools 8.44 has enhancements to process scheduler to resolve this situation automatically. Prior to that release, some customers have written a script that kills old PSNVS or Excel processes.

Some customers will also segment existing hardware using windows terminal server to have multiple virtual machines to run nVision reports. You can then configure a process scheduler server for each virtual machine and really run excel in parallel without contention. This approach should virtually eliminate the problem, if I’m right as to what it is.

Labels: ,

Stay Updated

Request a Demo