Re: database shutdown with persistent client connections

tgl(at)sss(dot)pgh(dot)pa(dot)us (Tom Lane) wrote in message news:<27612(dot)1028124591(at)sss(dot)pgh(dot)pa(dot)us>...
> g(dot)hintermayer(at)inode(dot)at (Gerhard Hintermayer) writes:
> > Is there a notification sen't out in either smart or fast shutdown
> > mode ?
>
> Sure: the backend sends an error message
> FATAL: This connection has been terminated by the administrator.
> before closing the connection.
>
> The problem you're describing is that the client-side code isn't looking
> for any communication from the server except when it's involved in a SQL
> command. I'm not sure what you can do about that except restructure the
> client.
>

What I tried is (for libpgtcl):
Everytime if I do PQconsumeInput (when the backend channel gets
readable) I check for the return value. (0 == error) and generate a
notification manually, e.g. connection_closed) and pass it to the TCL
event queue. The only bad thing I had to do is to comment out removing
all pending events in PgStopNotifyEventSource. Could there be any
sideeffects ? Maybe I should do that only if the connection was
unexpectedly closed (i.e. called from within PgNotifyTransferEvents) ?

Gerhard