Re: logical decoding and replication of sequences

At Mon, 08 Aug 2022 17:33:22 +0900 (JST), Kyotaro Horiguchi <horikyota.ntt@gmail.com> wrote in 
> If WaitForWALToBecomeAvailable returned by promotion, ReadPageInteral
> misses the chance to inavlidate reader-state.  That state is not an
> error while in StandbyMode.

Mmm... Maybe I wanted to say:  (Still I'm not sure the rewrite works..)

If WaitForWALToBecomeAvailable returned by promotion, ReadPageInteral
would miss the chance to invalidate reader-state.  When XLogPageRead
is called in blocking mode while in StandbyMode (that is, the
traditional condition) , the function continues retrying until it
succeeds, or returns XLRAD_FAIL if promote is triggered.  In other
words, it was not supposed to return non-failure while the header
validation is failing while in standby mode.  But while in nonblocking
mode, the function can return non-failure with lastSourceFailed =
true, which seems wrong.


regards.

-- 
Kyotaro Horiguchi
NTT Open Source Software Center