On 10/16/14, 11:46 PM, David G Johnston wrote:
Tom Lane-2 wrote
Something else mentioned was that once you start a smart shutdown you
have no good way (other than limited ps output) to see what the shutdown
is waiting on. I'd like to have some way to get back into the database
to see what's going on. Perhaps we could allow superusers to connect
while waiting for shutdown.
I think this idea is going to founder on the fact that the postmaster
has no way to tell whether an incoming connection is for a superuser.
You don't find that out until you've connected to a database and run
a transaction (so you can read pg_authid). And by that point, you've
already had a catastrophic impact on any attempt to shut things down.
This quote from the documentation seems suspect in light of your comment...
"While backup mode is active, new connections will still be allowed, but
only to superusers (this exception allows a superuser to connect to
terminate online backup mode)."
http://www.postgresql.org/docs/9.3/interactive/server-shutdown.html
check_hba() does
if (!check_role(port->user_name, roleid, hba->roles))
continue;
And check_role(char **newval, void **extra, GucSource source) does
is_superuser = ((Form_pg_authid) GETSTRUCT(roleTup))->rolsuper;
...
myextra->roleid = roleid;
myextra->is_superuser = is_superuser;
*extra = (void *) myextra;
So presumably with some changes to how we're calling check_role() we could
determine if port->user_name is a superuser.
I also like the idea of specifying that a connection should be terminated by a
smart shutdown; I agree that'd be useful for monitoring tools and what-not. If
folks agree with that I can take a stab at implementing it.
Since I tend to be paranoid, I like smart being the default, but seems I'm in
the minority there.
--
Jim Nasby, Data Architect, Blue Treble Consulting
Data in Trouble? Get it in Treble! http://BlueTreble.com
--
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers
