Re: pgsql/doc/TODO.detail (alpha default distinct flock fsync function limit null pg_shadow primary) - Mailing list pgsql-committers

From Tom Lane
Subject Re: pgsql/doc/TODO.detail (alpha default distinct flock fsync function limit null pg_shadow primary)
Date
Msg-id 28151.962739563@sss.pgh.pa.us
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In response to Re: pgsql/doc/TODO.detail (alpha default distinct flock fsync function limit null pg_shadow primary)  (eisentrp@csis.gvsu.edu)
Responses Re: pgsql/doc/TODO.detail (alpha default distinct flock fsync function limit null pg_shadow primary)
List pgsql-committers
eisentrp@csis.gvsu.edu writes:
> On Tue, 4 Jul 2000, Bruce Momjian - CVS wrote:
>> Removed Files:
>> alpha default distinct flock fsync function limit null
>> pg_shadow primary

> What are we going to do with the flock? Remove it? I asked about this
> yesterday, I guess it's not useful anymore.

It still is, because the $PGDATA pid file only guards against starting
two postmasters in the same data directory.  You still need some lock
against starting two postmasters on the same port number.  The TCP
socket address can take care of itself, but if one or both postmasters
is started without -i then there's got to be some interlock on the Unix
socket file.

I don't much like depending on flock for that, since it isn't available
everywhere.  The only portable answer is to build a pid-containing
interlock file for each socket file, as discussed in the TODO item.

It was premature of Bruce to delete the flock TODO file, since there is
still a lot of undone stuff in there concerning both this issue and
moving the Unix-socket file to a safer place than /tmp.

            regards, tom lane

PS: Hey Bruce, mail directly to your personal address
pgman@candle.pha.pa.us has been bouncing since Sunday.

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