Bad interaction: win task scheduler running PHP code accessing QODBC DSN
From testing the following replicable behavior occurred when running a .bat file via the Windows task scheduler that in turn runs ForceField PHP code that accesses QB tables via QODBC (using win server 2008):
1. PHP code runs fine for about 5 successive scheduled iterations, then crashes. Note that the same PHP code runs flawlessly when run manually.
2. crashes with "Cannot create DCOM instance" errors.
3. subsequent execution of code fails because process can't write to sync_log.txt.
4. Running the .bat manually from the task scheduler doesn't work.
4. RDP session crashes.
5. upon re-boot, .bat run manually works fine.
6. Item #1 recurs.
Solved all of these problems by using a shareware task scheduler at:
Apparently there are serious flaws in the MS task scheduler interacting with DCOM, UAC, and RDP.
I've seen variations on this theme and suspect that a third party task scheduler could be very helpful.