Re: Standby got invalid primary checkpoint after crashed right after promoted.

Found this issue is duplicated to [1], after applied that patch, I cannot reproduce it anymore.

[1] https://www.postgresql.org/message-id/flat/20220316.102444.2193181487576617583.horikyota.ntt%40gmail.com<https://www.postgresql.org/message-id/flat/20220316(dot)102444(dot)2193181487576617583(dot)horikyota(dot)ntt(at)gmail(dot)com>

2022年3月16日 下午3:16，hao harry <harry-hao(at)outlook(dot)com<mailto:harry-hao(at)outlook(dot)com>> 写道：

Hi, pgsql-hackers,

I think I found a case that database is not recoverable, would you please give a look?

Here is how it happens:

- setup primary/standby
- do a lots INSERT at primary
- create a checkpoint at primary
- wait until standby start doing restart point, it take about 3mins syncing buffers to complete
- before the restart point update ControlFile, promote the standby, that changed ControlFile
->state to DB_IN_PRODUCTION, this will skip update to ControlFile, leaving the ControlFile
->checkPoint pointing to a removed file
- before the promoted standby request the post-recovery checkpoint (fast promoted),
one backend crashed, it will kill other server process, so the post-recovery checkpoint skipped
- the database restart startup process, which report: "could not locate a valid checkpoint record"

I attached a test to reproduce it, it does not fail every time, it fails every 10 times to me.
To increase the chance CreateRestartPoint skip update ControlFile and to simulate a crash,
the patch 0001 is needed.

Best Regard.

Harry Hao

<0001-Patched-CreateRestartPoint-to-reproduce-invalid-chec.patch><reprod_crash_right_after_promoted.pl>