Thread: Database Synchronization

Database Synchronization

From
"Jyoti Seth"
Date:
<div class="Section1"><p class="MsoNormal">Hello ,<p class="MsoNormal"> <p class="MsoNormal">I have two postgres
databaseson different linux servers. Postgres database on one server has some tables that needs to be synchronized from
theother postgres database . What should be the best method for this.<p class="MsoNormal"> <p class="MsoNormal">Please
letme know if someone has idea.<p class="MsoNormal"> <p class="MsoNormal">Thanks,<p class="MsoNormal">Jyoti Seth</div> 

Re: Database Synchronization

From
Richard Huxton
Date:
Jyoti Seth wrote:
> Hello ,
> 
>  
> 
> I have two postgres databases on different linux servers. Postgres database
> on one server has some tables that needs to be synchronized from the other
> postgres database . What should be the best method for this.

The slony replication package lets you choose what tables you replicate. 
On the destination server the tables will be read-only.

http://www.slony.info/

Take a little time to read through the documentation and experiment with 
a test system first. It works fine, but it's got a lot of complicated 
options.

--   Richard Huxton  Archonet Ltd


Re: Database Synchronization

From
Chris Browne
Date:
dev@archonet.com (Richard Huxton) writes:
> Jyoti Seth wrote:
>> Hello ,
>>  I have two postgres databases on different linux servers. Postgres
>> database
>> on one server has some tables that needs to be synchronized from the other
>> postgres database . What should be the best method for this.
>
> The slony replication package lets you choose what tables you
> replicate. On the destination server the tables will be read-only.
>
> http://www.slony.info/
>
> Take a little time to read through the documentation and experiment
> with a test system first. It works fine, but it's got a lot of
> complicated options.

But it is worth noting one thing about the synchronization...

Slony-I's strategy is pretty simple: One node is considered the
"master," and the other node is forcibly made to conform to what is on
the master.

If you want to synchronize back and forth (e.g. - multimaster
replication of some sort), Slony-I is not suitable...
-- 
"cbbrowne","@","linuxdatabases.info"
http://www3.sympatico.ca/cbbrowne/unix.html
Culus thinks  we should go to trade  shows and see how  many people we
can kill by throwing debian cds at them


Re: Database Synchronization

From
Richard Huxton
Date:
Chris Browne wrote:
> dev@archonet.com (Richard Huxton) writes:
>>
>> http://www.slony.info/

> But it is worth noting one thing about the synchronization...
> 
> Slony-I's strategy is pretty simple: One node is considered the
> "master," and the other node is forcibly made to conform to what is on
> the master.
> 
> If you want to synchronize back and forth (e.g. - multimaster
> replication of some sort), Slony-I is not suitable...

Except in the case when you can have separate tables for the data. If 
you have a london_sales table only updated in London and a paris_sales 
table only updated in Paris then you have something inching towards 
multi-master.

--   Richard Huxton  Archonet Ltd


Re: Database Synchronization

From
"Jyoti Seth"
Date:
Thanks a lot for your suggestions. I have ony single master.

-----Original Message-----
From: pgsql-sql-owner@postgresql.org [mailto:pgsql-sql-owner@postgresql.org]
On Behalf Of Richard Huxton
Sent: Wednesday, July 18, 2007 9:13 PM
To: Chris Browne
Cc: pgsql-sql@postgresql.org
Subject: Re: [SQL] Database Synchronization

Chris Browne wrote:
> dev@archonet.com (Richard Huxton) writes:
>>
>> http://www.slony.info/

> But it is worth noting one thing about the synchronization...
> 
> Slony-I's strategy is pretty simple: One node is considered the
> "master," and the other node is forcibly made to conform to what is on
> the master.
> 
> If you want to synchronize back and forth (e.g. - multimaster
> replication of some sort), Slony-I is not suitable...

Except in the case when you can have separate tables for the data. If 
you have a london_sales table only updated in London and a paris_sales 
table only updated in Paris then you have something inching towards 
multi-master.

--   Richard Huxton  Archonet Ltd

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Re: Database Synchronization

From
"Jyoti Seth"
Date:
Hello,

When I am installing slony-I from rpm's available at the following
url:http://main.slony.info/downloads/1.2/rpm/ it is giving an error: There
are no installable providers of postgresql-slony1-engine.

In our system postgresql has been installed through YAST. So when we try to
install and configure slony-I through source, it gives the message please
make sure tp build and install postgresql from the sources first.

I am new to both linux and postgres. Please help me in installing and
configuring slony-I on my suse linux m/c.

Thanks,
Jyoti Seth 

-----Original Message-----
From: pgsql-sql-owner@postgresql.org [mailto:pgsql-sql-owner@postgresql.org]
On Behalf Of Chris Browne
Sent: Wednesday, July 18, 2007 8:28 PM
To: pgsql-sql@postgresql.org
Subject: Re: [SQL] Database Synchronization

dev@archonet.com (Richard Huxton) writes:
> Jyoti Seth wrote:
>> Hello ,
>>  I have two postgres databases on different linux servers. Postgres
>> database
>> on one server has some tables that needs to be synchronized from the
other
>> postgres database . What should be the best method for this.
>
> The slony replication package lets you choose what tables you
> replicate. On the destination server the tables will be read-only.
>
> http://www.slony.info/
>
> Take a little time to read through the documentation and experiment
> with a test system first. It works fine, but it's got a lot of
> complicated options.

But it is worth noting one thing about the synchronization...

Slony-I's strategy is pretty simple: One node is considered the
"master," and the other node is forcibly made to conform to what is on
the master.

If you want to synchronize back and forth (e.g. - multimaster
replication of some sort), Slony-I is not suitable...
-- 
"cbbrowne","@","linuxdatabases.info"
http://www3.sympatico.ca/cbbrowne/unix.html
Culus thinks  we should go to trade  shows and see how  many people we
can kill by throwing debian cds at them

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Re: Database Synchronization

From
Andrew Sullivan
Date:
On Mon, Jul 23, 2007 at 02:55:21PM +0530, Jyoti Seth wrote:
> In our system postgresql has been installed through YAST. So when we try to
> install and configure slony-I through source, it gives the message please
> make sure tp build and install postgresql from the sources first.
> 

You _might_ be able to get this to work by installing whatever extra
bits the YAST installation tool offers (probably something with -dev-
or -src- in it).

A

-- 
Andrew Sullivan  | ajs@crankycanuck.ca
Users never remark, "Wow, this software may be buggy and hard 
to use, but at least there is a lot of code underneath."    --Damien Katz


Re: Database Synchronization

From
"Jyoti Seth"
Date:
Hello,

Thanks Andrew for the solution. I have successfully installed following rpm
<< postgresql-slony1-engine-1.1.5-1_PG8.1.4.i686.rpm >> available at
http://main.slony.info/downloads/1.1/rpm/.

But when I am trying to set a cluster its throwing a following error:
<stdin>:4: PGRES_FATAL_ERROR load '$libdir/xxid';  - ERROR:  could not
access file "$libdir/xxid": No such file or directory
<stdin>:4: Error: the extension for the xxid data type cannot be loaded in
database 'dbname=contactdb host=localhost user=postgres'
<stdin>:4: ERROR: no admin conninfo for node 134590736

I have also tried changing the value of libdir to the directory where
xxid.so file is there but couldn't resolve the problem. 

Thanks,
Jyoti Seth

-----Original Message-----
From: pgsql-sql-owner@postgresql.org [mailto:pgsql-sql-owner@postgresql.org]
On Behalf Of Andrew Sullivan
Sent: Monday, July 23, 2007 11:43 PM
To: pgsql-sql@postgresql.org
Subject: Re: [SQL] Database Synchronization

On Mon, Jul 23, 2007 at 02:55:21PM +0530, Jyoti Seth wrote:
> In our system postgresql has been installed through YAST. So when we try
to
> install and configure slony-I through source, it gives the message please
> make sure tp build and install postgresql from the sources first.
> 

You _might_ be able to get this to work by installing whatever extra
bits the YAST installation tool offers (probably something with -dev-
or -src- in it).

A

-- 
Andrew Sullivan  | ajs@crankycanuck.ca
Users never remark, "Wow, this software may be buggy and hard 
to use, but at least there is a lot of code underneath."    --Damien Katz

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