Обсуждение: ODBC and pgpool
If a Win-32 system connects via ODBC to pgpool, does the system running pgpool have to be permanently running or can it be rebooted without deranging open but quiescent connections? If it /can/ be rebooted can it also be transferred from one machine to another, e.g. by changing the location of the IP alias? If it /can't/ be rebooted without breaking ODBC how does one prevent this from being a single point of failure? -- Mark Morgan Lloyd markMLl .AT. telemetry.co .DOT. uk [Opinions above are the author's, not those of his employers or colleagues]
> If a Win-32 system connects via ODBC to pgpool, does the system > running pgpool have to be permanently running or can it be rebooted > without deranging open but quiescent connections? I don't know how is pgpool working. It's not ODBC related question. You need to know how pgpool is working. The questionis if all communication goes through pgpool machine or not. psqlODBC realizes no multipath so when you need no single point of failure you have to realize it by another way. Regards, Luf
Mark Morgan Lloyd wrote: > If a Win-32 system connects via ODBC to pgpool, does the system > running pgpool have to be permanently running or can it be rebooted > without deranging open but quiescent connections? No, your application will have to be able to reconnect if the connection is lost by reason of the "server" disappearing or having been moved. -- Peter Eisentraut http://developer.postgresql.org/~petere/
Many thanks. Not the most desirable situation but at least it's a clear answer. My current situation is that I'm using Delphi on the clients, this has data-aware components that adopt undefined (or at the very least inconvenient :-) states when no longer connected to the underlying database. However I have aother reasons to want to discard these, so this becomes just one more factor to consider in the redesign. Peter Eisentraut wrote: > > Mark Morgan Lloyd wrote: > > If a Win-32 system connects via ODBC to pgpool, does the system > > running pgpool have to be permanently running or can it be rebooted > > without deranging open but quiescent connections? > > No, your application will have to be able to reconnect if the connection > is lost by reason of the "server" disappearing or having been moved. -- Mark Morgan Lloyd markMLl .AT. telemetry.co .DOT. uk [Opinions above are the author's, not those of his employers or colleagues]
I'd try zeoslib instead see http://forum.zeoslib.net.ms/. It's not perfect but works well for what I'm using it for. Regard Ben "Mark Morgan Lloyd" <markMLl.pgsql-odbc@telemetry.co.uk> wrote in message news:43E0999E.7281D1F@telemetry.co.uk... > Many thanks. Not the most desirable situation but at least it's a clear > answer. > > My current situation is that I'm using Delphi on the clients, this has > data-aware components that adopt undefined (or at the very least > inconvenient > :-) states when no longer connected to the underlying database. However I > have > aother reasons to want to discard these, so this becomes just one more > factor to > consider in the redesign. > > Peter Eisentraut wrote: >> >> Mark Morgan Lloyd wrote: >> > If a Win-32 system connects via ODBC to pgpool, does the system >> > running pgpool have to be permanently running or can it be rebooted >> > without deranging open but quiescent connections? >> >> No, your application will have to be able to reconnect if the connection >> is lost by reason of the "server" disappearing or having been moved. > > -- > Mark Morgan Lloyd > markMLl .AT. telemetry.co .DOT. uk > > [Opinions above are the author's, not those of his employers or > colleagues] > > ---------------------------(end of broadcast)--------------------------- > TIP 6: explain analyze is your friend >
Sure, when I've had time to rewrite the apps. I'm not trying to be flip, I mean it since I'm interested in porting to Lazarus and preferably getting off x86. Right now the apps use ODBC but I'm planning a server upgrade since I need some of the newer facilities and want to eliminate as many points of failure as possible. What would be nice would be if ODBC could itself failover between servers, but from the point of view of this ML that comment's just from another kvetching luser- I've got neither the time nor the C expertise to get directly involved. Ben Trewern wrote: > > I'd try zeoslib instead see http://forum.zeoslib.net.ms/. It's not perfect > but works well for what I'm using it for. > > Regard > > Ben > > "Mark Morgan Lloyd" <markMLl.pgsql-odbc@telemetry.co.uk> wrote in message > news:43E0999E.7281D1F@telemetry.co.uk... > > Many thanks. Not the most desirable situation but at least it's a clear > > answer. > > > > My current situation is that I'm using Delphi on the clients, this has > > data-aware components that adopt undefined (or at the very least > > inconvenient > > :-) states when no longer connected to the underlying database. However I > > have > > aother reasons to want to discard these, so this becomes just one more > > factor to > > consider in the redesign. > > > > Peter Eisentraut wrote: > >> > >> Mark Morgan Lloyd wrote: > >> > If a Win-32 system connects via ODBC to pgpool, does the system > >> > running pgpool have to be permanently running or can it be rebooted > >> > without deranging open but quiescent connections? > >> > >> No, your application will have to be able to reconnect if the connection > >> is lost by reason of the "server" disappearing or having been moved. -- Mark Morgan Lloyd markMLl .AT. telemetry.co .DOT. uk [Opinions above are the author's, not those of his employers or colleagues]
Apologies for being a pain but I wonder if I could aske for a further clarifiaction on this. Peter Eisentraut wrote: > > Mark Morgan Lloyd wrote: > > If a Win-32 system connects via ODBC to pgpool, does the system > > running pgpool have to be permanently running or can it be rebooted > > without deranging open but quiescent connections? > > No, your application will have to be able to reconnect if the connection > is lost by reason of the "server" disappearing or having been moved. Does pgpool hide transitions from the live to a backup server, or is this likely to interrupt ODBC sessions as well? -- Mark Morgan Lloyd markMLl .AT. telemetry.co .DOT. uk [Opinions above are the author's, not those of his employers or colleagues]