Re: PANIC caused by open_sync on Linux

On Fri, 26 Oct 2007, Andrew Sullivan wrote:

> Sort of a filthy hack, but what about always having an _extra_
> segment around?  The bgwriter could do that, no?

Now it could.  The bgwriter in <=8.2 stops executing when there's a 
checkpoint going on, and needing more WAL segments because a checkpoint is 
taking too long is one of the major failure cases where proactively 
creating additional segments would be most helpful.

The 8.3 bgwriter keeps running even during checkpoints, so it's feasible 
to add such a feature now.  But that only became true well into the 8.3 
feature freeze, after some changes Heikki made just before the "load 
distributed checkpoint" patch was commited.  Before that, it was hard to 
implement this feature; afterwards, it was too late to fit the change into 
the 8.3 release.  Should be easy enough to add to 8.4 one day.

--
* Greg Smith gsmith@gregsmith.com http://www.gregsmith.com Baltimore, MD