On 2/19/16 10:06 AM, Fujii Masao wrote:
> One concern is that there can be a "time" after the pg_control's state
> is changed to DB_IN_PRODUCTION and before the server is able to
> start accepting normal (not read-only) connections. So if users try to
> start write transaction just after pg_ctl promote -w ends, they might
> get an error because the server is still in recovery, i.e., the startup
> process is running.
I think that window would be acceptable.
If not, then the way to deal with it would seem to be to create an
entirely new mechanism to communicate with pg_ctl (e.g., a file) and
call that at the very end of StartupXLOG(). I'm not sure that that is
worth it.