Sean Gallardy troubleshoots an error:
The symptoms of this issue were interesting, every so often the instance would just kind of get “stuck” – at least that is how it was described to me. Nothing would work, cancelling queries, attempting to kill queries, submitting anything new, nothing seemed to really do anything except restarting the service. Once the service was restarted, the instance (and AG) would hum along nicely… until some random time later when submitting different queries would just grind to a halt. Fun.
The answer is just as dumb as you’d think. But I won’t spoil the punch line here.