Re: FDW wrapper for clustered app management

Hello John,
Thanks for your answer. I am also considering a publish/subscribe MQ based
solution (and this may be indeed needed for queuing RPCs).

the data I would like to access R/W is more like
- configuration data
- states of different state machines
- cache values for some keys (reading, invalidating)

so you could in a sense say that they are table oriented.

I agree that this becomes 'tangential' with write access.
a request like "UPDATE server.service SET start_requested = true WHERE name
= 'myService' and started = false" seems weird but it could probably work.

Thanks,
Jerome

On Fri, Oct 17, 2014 at 11:57 AM, John R Pierce <pierce(at)hogranch(dot)com> wrote:

> On 10/17/2014 2:35 AM, Jerome Wagner wrote:
>
>> Hello,
>>
>> I am considering (postgres 9.3+) the idea of opening a R/W access into a
>> clustered application by creating one fdw server from a central database to
>> each server a cluster.
>>
>> That would imply opening a port on each server inside the application,
>> listening for incoming connections from the database and this way all the
>> servers would become visible with R/W access.
>>
>> Is that a sound idea or does it look horrible ? Would it be reasonable to
>> connect in this way to a cluster of 1, 10, 100, 1000 or more servers ?
>>
>> is there an existing xxxx_fdw wrapper that would look like a good
>> candidate for such a direct access inside an application ? Then I would
>> have to implement the protocol corresponding to this xxxx_fdw inside my
>> application.
>>
>>
> is the application running on these 10, 100, 1000 nodes something
> resembling a table oriented relational database?
>
> I would suggest instead you look at using a MQ style message queueing
> system, with publish-subscribe semantics for your distributed remote
> procedure calls. and not from within a database, rather, from your central
> control application to your distributed application workers...
>
>
>
>
> --
> john r pierce 37N 122W
> somewhere on the middle of the left coast
>
>
>
> --
> Sent via pgsql-general mailing list (pgsql-general(at)postgresql(dot)org)
> To make changes to your subscription:
> http://www.postgresql.org/mailpref/pgsql-general
>