We use Windows Task Scheduler on Win2008/R2 to run a small Powershell job every 15 minutes. It creates a small XML file which triggers a BizTalk process to run, so it typically takes under 1 second to run.
A week ago, it skipped two consecutive intervals, such as 3:00 and 3:15am. All other intervals ran as normal. Any idea of how this could happen, and what I might look for. This is based on looking at the history of the job.
This history has now rolled off, but I have a screen shot that I saved:
You can see from above it ran at 2:45 and not again until 3:29 (about 3:30).