Re: WIP: WAL prefetch (another approach) - Mailing list pgsql-hackers

From Andres Freund
Subject Re: WIP: WAL prefetch (another approach)
Date
Msg-id 20210428163245.ff67pb2ii5irr5zr@alap3.anarazel.de
Whole thread Raw
In response to Re: WIP: WAL prefetch (another approach)  (Thomas Munro <thomas.munro@gmail.com>)
Responses Re: WIP: WAL prefetch (another approach)  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
Hi,

On 2021-04-22 13:59:58 +1200, Thomas Munro wrote:
> On Thu, Apr 22, 2021 at 1:21 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
> > I've also tried to reproduce on 32-bit and 64-bit Intel, without
> > success.  So if this is real, maybe it's related to being big-endian
> > hardware?  But it's also quite sensitive to $dunno-what, maybe the
> > history of WAL records that have already been replayed.
> 
> Ah, that's interesting.  There are a couple of sparc64 failures and a
> ppc64 failure in the build farm, but I couldn't immediately spot what
> was wrong with them or whether it might be related to this stuff.
> 
> Thanks for the clues.  I'll see what unusual systems I can find to try
> this on....

FWIW, I've run 32 and 64 bit x86 through several hundred regression
cycles, without hitting an issue. For a lot of them I set
checkpoint_timeout to a lower value as I thought that might make it more
likely to reproduce an issue.

Tom, any chance you could check if your machine repros the issue before
these commits?

Greetings,

Andres Freund



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