Re: [COMMITTERS] pgsql: Upgrade to Autoconf 2.69

Hi,

On 2013-12-24 12:58:04 -0300, Alvaro Herrera wrote:
> > Shortly after this patch was committed, buildfarm member locust (running
> > Mac OS X 10.5 apparently) started failing the pg_upgrade check:
> >
> > command: "/Users/pgbuildfarm/Documents/workdir/HEAD/pgsql.82393/contrib/pg_upgrade/tmp_check/install//Users/pgbuildfarm/Documents/workdir//HEAD/inst/bin/pg_ctl" -w -l "pg_upgrade_server.log" -D "/Users/pgbuildfarm/Documents/workdir/HEAD/pgsql.82393/contrib/pg_upgrade/tmp_check/data" -o "-p 57632 -b -c synchronous_commit=off -c fsync=off -c full_page_writes=off -c listen_addresses='' -c unix_socket_permissions=0700 -c unix_socket_directories='/Users/pgbuildfarm/Documents/workdir/HEAD/pgsql.82393/contrib/pg_upgrade'" start >> "pg_upgrade_server.log" 2>&1
> > waiting for server to start....LOG: database system was shut down at 2013-12-19 12:51:16 CET
> > LOG: invalid primary checkpoint record
> > LOG: invalid secondary checkpoint link in control file
> > PANIC: could not locate a valid checkpoint record
>
> Any comment on this problem? Somehow ReadRecord is unable to find a
> checkpoint, yet there's no error message to be seen anywhere, whereas
> pg_resetxlog does report it:
>
> > command: "/Users/pgbuildfarm/Documents/workdir/HEAD/pgsql.82393/contrib/pg_upgrade/tmp_check/install//Users/pgbuildfarm/Documents/workdir//HEAD/inst/bin/pg_resetxlog" -l 000000010000000000000009 "/Users/pgbuildfarm/Documents/workdir/HEAD/pgsql.82393/contrib/pg_upgrade/tmp_check/data" >> "pg_upgrade_utility.log" 2>&1
> > pg_resetxlog: could not read from directory "pg_xlog": Invalid argument
>
> I cannot but think xlogreader is at fault.
>
> Regardless of the solution to the Mac OS X problem, ISTM this should be
> fixed.

I didn't look at any code, and I won't today, but it doesn't look
surprising - the report when starting the server above is presumable the
one in ReadCheckpoint() (or similar) and it probably just reports that
ReadRecord() didn't return a record.
pg_resetxlog (which doesn't use xlogreader!) reports that it couldn't
read from directory "pg_xlog", so there's something wonky independently
from xlogreader. I'd guess that xlog.c read_page callback errors out
without reporting an error. IIRC we're logging some failures as DEBUG
there, because they really aren't unexpected, and normally just signal
the end of wal.

Greetings,

Andres Freund

--
Andres Freund http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services