Re: Stefan's bug (was: max_standby_delay considered harmful)

On Mon, May 17, 2010 at 10:20 PM, Robert Haas <robertmhaas@gmail.com> wrote:
> OK, I think I understand now.  But, the SIGTERM sent by the postmaster
> doesn't kill the recovery process unconditionally.  It will invoke
> StartupProcShutdownHandler(), which will set set shutdown_requested =
> true.  That gets checked by RestoreArchivedFile() and
> HandleStartupProcInterrupts(), and I think that neither of those can
> get invoked until after the control file has been updated.  Do you see
> a way it can happen?

Yeah, the way is:
StartupXLOG() --> ReadCheckpointRecord() --> ReadRecord() -->
XLogPageRead() --> XLogFileReadAnyTLI() --> XLogFileRead() -->
RestoreArchivedFile()

ReadCheckpointRecord() is called before pg_control is updated.


ISTM that walreceiver might be invoked even after shutdown is requested.
We should prevent the postmaster from starting up walreceiver if
Shutdown > NoShutdown?

Regards,

--
Fujii Masao
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center