Re: Replication advice Many-to-one Slony

Hello Walfred,

yes you can use slony, we use slony for huge data replication. One
solution of them is the backup of many masters to one slave.

It is in real time - and we're quite happy with the newest version
of slony.

Don't forget to not only add tables to your replication but to also
add sequences additionally, because you may backup the tables and
content of them but when trying to use your backup you could have a
big nightmare when you cannot find the state of your sequences - so
your data is not lost but not instantly usable.

When you think of using a hot-copy system so that you just can
switch from the master when it brakes to your slave system I would
suggest you to think about the load that could go to the
backup-slave which should now be used as master, in this case we
calculate 1/3 of master-load to one slave, but that depends on the
application and the load of your databases.

Switching to Slave and back to master when it's again ready (also
with automatic replication back to the master) works great in slony.

If you have any further questions or need any help on setting up the
slony scripts just contact me directly.

Regards,

Aldor

Walfred Tedeschi wrote:
> Hi all,
>
> We intend to establish a central back-up for our system. It can be though as
> many machines (masters) linked to one Slave. The communication may be one
> directional (master -> slave) and would appreciate to have it almost in realtime.
> The data flux on the system is not very high in terms of transactions and
> volume of data. And the primary keys are planned in a way that there is no
> overlap over the masters (every master has its own range of PK) without
> overlapping. We were thinking about slony1.
>
> Since we are not sure about the decision, we would appreciate very much if you
> could advise us what to use and where to start.
>
> Thank you very much,
>
> Fred
>
>
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