Re: Postgres server crash

Richard Huxton <dev@archonet.com>

From: Richard Huxton <dev@archonet.com>
To: "Craig A. James" <cjames@modgraph-usa.com>
Cc: Russell Smith <mr-russ@pws.com.au>, pgsql-performance@postgresql.org
Date: 2006-11-16T17:29:58Z
Lists: pgsql-performance
Craig A. James wrote:
> By the way, in spite of my questions and concerns, I was *very* 
> impressed by the recovery process.  I know it might seem like old hat to 
> you guys to watch the WAL in action, and I know on a theoretical level 
> it's supposed to work, but watching it recover 150 separate databases, 
> and find and fix a couple of problems was very impressive.  It gives me 
> great confidence 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 signals at critical points?

If a "kill -9" as root doesn't get rid of them, I think I'm right in 
saying that it's a kernel-level problem rather than something else.

-- 
   Richard Huxton
   Archonet Ltd