Re: replication questions

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From: Doug Needham <dneedham(at)pbo(dot)net>
To: Pgsql Hackers <pgsql-hackers(at)postgresql(dot)org>
Subject: replication questions
Date: 2002-05-02 18:10:56
Message-ID: 200205021922.g42JMuO16578@pbo.net
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I am a bit new to postgresql. I have used it in a few applications, however,
in the current application we are beginning to see a need for replicated
databases. I am trying to find out more information about how to do automatic
replication with postgresql.
I have gone through the basic rserv tutorial, and I have a basic
understanding of how it works. However, I have noticed there are a number of
replication projects currently underway.

My questions are :

1) Is this the correct forum to ask this question?
2) What is the "recomended" replication solution project?
3) How are others doing replication?

Thanks,

Doug


From: Darren Johnson <darren(at)up(dot)hrcoxmail(dot)com>
To: dneedham(at)pbo(dot)net
Cc: Pgsql Hackers <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: replication questions
Date: 2002-05-02 23:54:11
Message-ID: 3CD1D1A3.8010702@up.hrcoxmail.com
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>databases. I am trying to find out more information about how to do automatic
>replication with postgresql.
>

We did some research on this several months ago, and published the
results here

http://gborg.postgresql.org/genpage?replication_research

>
>
>
> My questions are :
>
> 1) Is this the correct forum to ask this question?
>
This is probably better suited for general, but its a topic I'm
interested in.

>
> 2) What is the "recomended" replication solution project?
>
IMHO, Postres-R has the potential to be great solution, but I'm sure
others have different
needs. ;-)

>
> 3) How are others doing replication?
>
If you asking for approaches, I'd say the majority are master/slave
asynchronous
with either triggers or transaction logs.

I would ask what are you trying to solve with replication. Do you want
to be able
update all systems in the replica? How much bandwidth do you have
between the
servers. Do the systems need to be identical at all times? What is
your time frame?

Depending on how you answer questions like these, your "recommendation"
will change.

Good luck,

Darren


From: Doug Needham <dneedham(at)pbo(dot)net>
To: Darren Johnson <darren(at)up(dot)hrcoxmail(dot)com>
Cc: Pgsql Hackers <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: replication questions
Date: 2002-05-03 04:03:21
Message-ID: 200205030515.g435FMO19000@pbo.net
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On Thursday 02 May 2002 07:54 pm, Darren Johnson wrote:
> >databases. I am trying to find out more information about how to do
> > automatic replication with postgresql.
>
> We did some research on this several months ago, and published the
> results here
>
> http://gborg.postgresql.org/genpage?replication_research
>
> > My questions are :
> >
> > 1) Is this the correct forum to ask this question?
>
> This is probably better suited for general, but its a topic I'm
> interested in.
>
> > 2) What is the "recomended" replication solution project?
>
> IMHO, Postres-R has the potential to be great solution, but I'm sure
> others have different
> needs. ;-)
>
> > 3) How are others doing replication?
>
> If you asking for approaches, I'd say the majority are master/slave
> asynchronous
> with either triggers or transaction logs.
>
>
> I would ask what are you trying to solve with replication. Do you want
> to be able
> update all systems in the replica?
yes.
How much bandwidth do you have
> between the
> servers.
We will have plenty.
> Do the systems need to be identical at all times?
Pretty much.
>What is
> your time frame?
Possibly as soon as six-nine months.

Our replication solution is shooting for the moon.
The scenario pitched to me (I'm the DBA for this application) is potentially
having multiple web applications accessing multiple databases and having
replication keep them all in sync.
I have to decide if in this scenario we have the multiple front end's connect
to a single master database and then have replication move the data to all of
the backend databases and then notify the backend processes or to have a
different scenario.

The specific scenario that marketing/management has given me is to have two
instances of the same front-end located in different parts of the country,
each updating a local database and the database ensures that the updates from
both locations get to the "peer-database". So end user in location A is able
to see all updates done to database A and database B for the data that they
have premission for.

I know this sounds confusing, it is. I have been doing DBA things for quite a
while, but I am a litle new to the replication thing.

Thanks,

Doug

>
> Depending on how you answer questions like these, your "recommendation"
> will change.
>
> Good luck,
>
> Darren
>
>
>
>
>
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