By the way, in spite of my questions and concerns, I was *very* impressed by the recovery process. I know it might
seemlike old hat to you guys to watch the WAL in action, and I know on a theoretical level it's supposed to work, but
watchingit recover 150 separate databases, and find and fix a couple of problems was very impressive. It gives me
greatconfidence that I made the right choice to use Postgres.
Richard Huxton wrote:
>>> 2. Why didn't the database recover? Why are there two processes
>>> that couldn't be killed?
>
> I'm guessing it didn't recover *because* there were two processes that
> couldn't be killed. Responsibility for that falls to the
> operating-system. I've seen it most often with faulty drivers or
> hardware that's being communicated with/written to. However, see below.
It can't be a coincidence that these were the only two processes in a SELECT operation. Does the server disable
signalsat critical points?
I'd make a wild guess that this is some sort of deadlock problem -- these two servers have disabled signals for a
criticalsection of SELECT, and are waiting for something from the postmaster, but postmaster is dead.
This is an ordinary system, no hardware problems, stock RH FC3 kernel, stock PG 8.1.4, with 4 GB memory, and at the
momentthe database is running on a single SATA disk. I'm worried that a production server can get into a state that
requiresmanual intervention to recover.
Craig
