Re: Strange error in new 003_cic_2pc.pl test

> tadarida just reported this [1]:
> 
> 2021-11-11 14:40:40.040 CET [29620:388] 023_cic_2pc.pl ERROR: could not read two-phase state from WAL at 0/1716C68
> 
> That error message is remarkably unhelpful, and I think unnecessarily so.
> Why the heck isn't XlogReadTwoPhaseData passing on the error string
> that it just got from XLogReadRecord?
> 
> Now, XLogReadRecord's API spec does say it might return NULL errormsg
> if "the page read callback already reported the error". But there's
> no sign of that in tadarida's log. Anyway, I have in mind to do
> 
> ereport(ERROR,
> (errcode_for_file_access(),
> - errmsg("could not read two-phase state from WAL at %X/%X",
> - LSN_FORMAT_ARGS(lsn))));
> + errmsg("could not read two-phase state from WAL at %X/%X: %s",
> + LSN_FORMAT_ARGS(lsn),
> + errormsg ? errormsg : "(no details available)")));
> 

Noah recently proposed the same [0]. But responders like me started to complain about other places without error
reportingaround xlog reading.
 

Probably I had to be more clear on the matter. Error logging certainly worth doing, at least this.

Thanks!


Best regards, Andrey Borodin.

[0] https://www.postgresql.org/message-id/flat/20211107013157.GB790288%40rfd.leadboat.com