Thread: AW: F_SETLK is looking worse and worse...

AW: F_SETLK is looking worse and worse...

From
Zeugswetter Andreas SB
Date:
> BTW, it also seems like a good idea to reorder the postmaster's
> startup operations so that the data-directory lockfile is checked
> before trying to acquire the port lockfile, instead of after.  That
> way, in the common scenario where you're trying to start a second
> postmaster in the same directory + same port, it'd fail cleanly
> even if /tmp/.s.PGSQL.5432.lock had disappeared.

Fine, sounds like reordering would eliminate the need for the socket lock 
anyway, no ?

Andreas


Re: AW: F_SETLK is looking worse and worse...

From
Tom Lane
Date:
Zeugswetter Andreas SB <ZeugswetterA@wien.spardat.at> writes:
>> BTW, it also seems like a good idea to reorder the postmaster's
>> startup operations so that the data-directory lockfile is checked
>> before trying to acquire the port lockfile, instead of after.  That
>> way, in the common scenario where you're trying to start a second
>> postmaster in the same directory + same port, it'd fail cleanly
>> even if /tmp/.s.PGSQL.5432.lock had disappeared.

> Fine, sounds like reordering would eliminate the need for the socket lock 
> anyway, no ?

Not at all.  If you start two postmasters in different data directories
but with the same port number, you still have a socket-file conflict
that needs to be detected.
        regards, tom lane