Re: 8.4-vintage problem in postmaster.c

On 11/13/2010 06:58 PM, Tom Lane wrote:
> Alvaro Herrera<alvherre(at)alvh(dot)no-ip(dot)org> writes:
>> Stefan Kaltenbrunner reported a problem in postmaster via IM to me. I
>> thought I had nailed down the bug, but after more careful reading of the
>> code, turns out I was wrong.
>
>> The reported problem is that postmaster shuts itself down with this
>> error message:
>
>> 2010-11-12 10:19:05 CET FATAL: no free slots in PMChildFlags array
>
> Just looking at it, I think that the logic in canAcceptConnections got
> broken by somebody in 8.4, and then broken some more in 9.0: in some
> cases it will return an "okay to proceed" status without having checked
> for TOOMANY children. Was this system possibly in PM_WAIT_BACKUP or
> PM_HOT_STANDBY state? What version was actually running?

I don't have too many details on the actual setup (working on that) but
the box in question is running 8.4.2 and had no issues before the
upgrade to 8.4 (ie 8.3 was reported to work fine - so a 8.4+ breakage
looks plausible).

Stefan