Re: Found this in the server log on MAC OSX - Mailing list pgsql-general

Tom,

Let me clarify.... I was meant shutdown in the context of issuing a stop
against postgres not shutting down the OS.  Sorry if I am confusing things.

The scripts we are using to issue start, stop etc for postgres seem to
be causing the issue.  I changed the config to use timestamps in the log
and the act of stopping and starting the server caused the same error to
occur. :-(

 From the scripts we are using:

StartService ()
{
        if [ "${POSTGRES:=-YES-}" = "-YES-" ]; then

            ConsoleMessage "Starting PostgreSQL database server"
            su - postgres -c '/usr/local/pgsql/bin/pg_ctl start -D
/usr/local/pgsql/data -l /usr/local/pgsql/data/logfile -o -i'

        fi
}

StopService()
{
        ConsoleMessage "Stopping PostgreSQL database services"
        /usr/local/pgsql/bin/pg_ctl stop -D /usr/local/pgsql/data
        x=`/bin/ps axc | /usr/bin/grep postgres`
        if /bin/test "$x"
        then
                set $x
                kill -9 $x
        fi
}


Thanks.

--sean


Tom Lane wrote:

>"Ed L." <pgsql@bluepolka.net> writes:
>
>
>>Uh, no, I didn't say signal 9 is SIGTERM.  Isn't a "smart" shutdown request
>>an indication of a SIGTERM?  I'm just speculating about what happened, but
>>isn't that what you'd see during a system shutdown?  The kernel sending
>>SIGTERMs?
>>
>>
>
>Yes, the trace is sort of consistent with the idea of a system shutdown:
>you'd see SIGTERMs issued, followed some time later by SIGKILL.
>I thought Sean had said that the machine did not shut down during this
>interval, and so mentally eliminated that theory --- but based on his
>latest comment I guess that is what happened after all.
>
>So that does leave me with a question: why didn't it work more cleanly?
>Our signal responses are designed around the assumption that during
>shutdown the kernel will send SIGTERM to *all* the Postgres processes.
>Backends interpret that as an immediate shutdown and should exit quickly
>enough to avoid getting SIGKILL'd later.  It looks like either the
>postmaster was sent SIGTERM but the backends weren't, or the interval
>between SIGTERM and SIGKILL was unreasonably short.  I don't think I
>believe the latter; the last time I checked this on Darwin, it seemed to
>be using the traditional 20-second grace period.
>
>Another question: if that was a shutdown we were looking at, how did the
>postmaster live long enough to record the final log lines?  It shoulda
>gotten SIGKILL'd at the same time as its children.
>
>In short, there's something pretty odd about the way these signals are
>being passed around.  It looks something like a standard system shutdown
>sequence, but not enough like it.
>
>            regards, tom lane
>
>
>