Re: Make mesage at end-of-recovery less scary.

At Sat, 19 Feb 2022 09:31:33 +0530, Ashutosh Sharma <ashu(dot)coek88(at)gmail(dot)com> wrote in
> The changes looks good. thanks.!

Thanks!

Some recent core change changed WAL insertion speed during the TAP
test and revealed one forgotton case of EndOfWAL. When a record
header flows into the next page, XLogReadRecord does separate check
from ValidXLogRecordHeader by itself.

> * If the whole record header is on this page, validate it immediately.
> * Otherwise do just a basic sanity check on xl_tot_len, and validate the
> * rest of the header after reading it from the next page. The xl_tot_len
> * check is necessary here to ensure that we enter the "Need to reassemble
> * record" code path below; otherwise we might fail to apply
> * ValidXLogRecordHeader at all.
> */
> if (targetRecOff <= XLOG_BLCKSZ - SizeOfXLogRecord)
> {
...
> }
> else
> {
> /* XXX: more validation should be done here */
> if (total_len < SizeOfXLogRecord)
> {

I could simplly copy-in a part of ValidXLogRecordHeader there but that
results in rather large duplicate code. I could have
ValidXLogRecordHeader handle the partial header case but it seems to
me complex.

So in this version I split the xl_tot_len part of
ValidXLogRecordHeader into ValidXLogRecordLength.

regards.

--
Kyotaro Horiguchi
NTT Open Source Software Center