Re: pg15b4: FailedAssertion("TransactionIdIsValid(xmax)

On Sat, Sep 10, 2022 at 5:01 PM Justin Pryzby <pryzby@telsasoft.com> wrote:
> BTW, after a number of sigabrt's, I started seeing these during
> recovery:
>
> < 2022-09-09 19:44:04.180 CDT  >LOG:  unexpected pageaddr 1214/AF0FE000 in log segment 0000000100001214000000B4,
offset1040384
 
> < 2022-09-09 23:20:50.830 CDT  >LOG:  unexpected pageaddr 1214/CF65C000 in log segment 0000000100001214000000D8,
offset6668288
 

That's just what it looks like when we discover the end of the WAL by
hitting a page that hasn't been overwritten yet in a recycled WAL
segment, so the pageaddr is off by a multiple of 16MB.  Depending on
timing and chance you might be more used to seeing the error where we
hit zeroes in a partially filled page, the famous 'wanted 24, got 0',
and you can also hit a fully zero-initialised page 'invalid magic
number 0000'.  All of these are expected, and more exotic errors are
possible with power loss torn writes or on crash of a streaming
standbys where we currently fail to zero the rest of overwritten
pages.