Re: 8.4-vintage problem in postmaster.c

Stefan Kaltenbrunner <stefan(at)kaltenbrunner(dot)cc> writes:
> On 11/13/2010 06:58 PM, Tom Lane wrote:
>> 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).

Well, this failure would certainly involve a flood of connection
attempts, so it's possible it's a pre-existing bug that they just did
not happen to trip over before. But the sequence of events that I'm
thinking about is a smart shutdown attempt (SIGTERM to postmaster)
while an online backup is in progress, followed by a flood of
near-simultaneous connection attempts while the backup is still active.

regards, tom lane