Обсуждение: Slony replication

Hi All,

I would like to implement DB replication with Slony but with a slave that will not be always available.
The master would have to check first of the slave's availability and then start syncing...

Is this at all possible, or am I just raving? : )

Kind regards,

-- Pedro Doria Meunier Ips da Olaria Edf. Jardins do Garajau, 4 r/c Y 9125-163 Caniço Madeira Portugal GSM: +351 96 17 20 188 Skype: pdoriam http://www.madeiragps.com

Pedro Doria Meunier wrote:
> Hi All,
>
> I would like to implement DB replication with Slony but with a slave
> that will not be always available.
> The master would have to check first of the slave's availability and
> then start syncing...
>
> Is this at all possible, or am I just raving? : )

I am quite new to Slony as well, but one of the first requirements the
docs state is:

  Thus, examples of cases where Slony-I probably won't work out well
would include:

     * Sites where connectivity is really "flakey"
     * Replication to nodes that are unpredictably connected.

So I suspect Slony is not a solution for your effort.  See:

http://slony.info/documentation/slonyintro.html#INTRODUCTION

--
Until later, Geoffrey

Those who would give up essential Liberty, to purchase a little
temporary Safety, deserve neither Liberty nor Safety.
  - Benjamin Franklin

On Dec 8, 2007, at 9:21 AM, Geoffrey wrote:

> I am quite new to Slony as well, but one of the first requirements
> the docs state is:
>
> Thus, examples of cases where Slony-I probably won't work out well
> would include:
>
>    * Sites where connectivity is really "flakey"
>    * Replication to nodes that are unpredictably connected.
>
> So I suspect Slony is not a solution for your effort.  See:

If your DB doesn't change very much (like a few hundred or thousand
update/insert/delete per day), then slony can work just fine in such a
batch mode.  Things break down when you accumulate several hundred
thousand or more changes between times when you're connected.