Re: Proposal: Implement failover on libpq connect level.

On 2015.08.19 at 12:55:15 +0530, Amit Kapila wrote:

> > I think that failover procedure should begin before first connection is
> > ever established.
> >
>
> As far as I understand, failover gets initiated once the master server goes
> down or is not accessible due to some reason, so for such cases if you
> have the connection to both the servers then it might not work.

Master server might go down when client is not started yet.
And when client starts up, it has to find out which server to connect
now.

Consider point-of-sale terminals, bank offices or anything else, which
do not work round the clock. Clerk comes to his workplace in the
morning, switches on terminal and inserts her smartcard to authorize
with server. She doesn't need to know what server name is and where it
is located. Either application finds the server automatically, or
support engineer has to be called to fix things.

Moreover, in some situations restart of application (or even client
terminal) is acceptable price for failover, as long as there is no need
to manually fix the configuration.