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Thread: PostgreSQL on a Cluster

PostgreSQL on a Cluster

From
Devrim GUNDUZ
Date:
Hi,

I am  trying to integrate an Enterprise level application to PostgreSQL.
I need answers to some questions:

This is what we are planning:


        +---------------+
        +   Storage    +
        +    Area    +
        +   Network    +
        +---------------+
            +
            +
        -----------------
        |        |
    Master Server       2nd Master
    with eRServer        Server
              for load balancing
               with eRServer


PostgreSQL can run only one server, right?

The PostgreSQL servers use SAN for storing data.

So let's say we want to do some operation on the database, located at SAN.
When the 1st server wants to update a row, it will lock it. What happens
when the second server wants to access the same row? Does 1st server
"broadcast" that it has locked the row?

Or... does MVCC have something with this?

How do we balance the load? Does eRServer do it; or should we use another
thing?

Maybe I need some documentation about these...

Thanks for reply.

Regards,

--
Devrim GUNDUZ
devrim@gunduz.org                devrim.gunduz@linux.org.tr
            http://www.gunduz.org

Re: PostgreSQL on a Cluster

From
Andrew Sullivan
Date:
On Sun, Apr 13, 2003 at 11:31:03PM +0300, Devrim GUNDUZ wrote:
> This is what we are planning:
>
>
>         +---------------+
>         +   Storage    +
>         +    Area    +
>         +   Network    +
>         +---------------+
>             +
>             +
>         -----------------
>         |        |
>     Master Server       2nd Master
>     with eRServer        Server
>               for load balancing

> So let's say we want to do some operation on the database, located at SAN.
> When the 1st server wants to update a row, it will lock it. What happens
> when the second server wants to access the same row? Does 1st server
> "broadcast" that it has locked the row?

This suggests you misunderstand how eRServer and PostgreSQL work.
There's no such thing as a "2d master".  It's impossible (well,
unless the eRServer folks have done something they haven't told the
rest of us about).

A

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