On 10/11/2015 14:49, TOINEL, Ludovic wrote:
> Is there a way to have subscribers with no direct SQL access to the provider ? 
> 
> The provider write the data on the subscribers directly.

(Top-posting makes it really hard to follow discussions in a thread.)

Your slon daemons need to run on a node that can see everyone.

So, for instance, you can have them on node A which is provider for SET 1 and
2, but subscriber of SET 3 from node B.
And you can't psql from NodeB to NodeA.


Should work.

(The provider logs modification on a log table, which is read by daemons. And
propagated to other nodes.)

> 
> -----Message d'origine-----
> De : slony1-general-bounces at lists.slony.info [mailto:slony1-general-bounces at lists.slony.info] De la part de Stéphane Schildknecht
> Envoyé : mardi 10 novembre 2015 14:45
> À : slony1-general at lists.slony.info
> Objet : Re: [Slony1-general] Network connection from slaves to the master
> 
> On 10/11/2015 14:03, TOINEL, Ludovic wrote:
>> Thanks Andrew,
>>
>> We are not allowed to have network connection from the slaves to the master (for security constraints).
> 
> You really should think about a VPN between nodes. It would simplify your architecture.
> 
> But, in theory, subscriber nodes could be on a DMZ. They can be accessed by daemons, but you don't need them to access providers.
> Your daemons would run on a node that can access every other node.
> 
> 
> BTW, there are no real master and slaves in Slony. There are nodes, which can be subscribers (receiving modifications readonly), and providers (read/write).
> And you can have a subscriber of a set that is provider of another.
> 
>  Only master can communicate with slaves.
>> We need database on slaves with mix replicates tables and read/write tables.
>>
>> The solution could be maybe that solution using a slony master has an Hot standby of a master protected somewhere ? 
>>
>> [slony slaves] <-----> [slony master - Standby node] <----(log 
>> shipping)--|firewall|-- [master protected somewhere]
>>
>> Do you think this solution can work with slony ?
>>
>> Regards,
>>
>> Ludovic Toinel
>>
>> -----Message d'origine-----
>> De : slony1-general-bounces at lists.slony.info 
>> [mailto:slony1-general-bounces at lists.slony.info] De la part de Andrew 
>> Sullivan Envoyé : mardi 10 novembre 2015 12:26 À : 
>> slony1-general at lists.slony.info Objet : Re: [Slony1-general] Network 
>> connection from slaves to the master
>>
>> On Tue, Nov 10, 2015 at 09:51:29AM +0000, TOINEL, Ludovic wrote:
>>> The network allows only flows from master to slaves.
>>>
>>> Is there any option that I missed to do that ?
>>
>> Not really.  In principle you could do this with the log shipping mode, but I don't recall whether doing that on the master was not possible or just a really bad idea.  (You could do this with the built-in standby mechanisms of Postgres, though.
>>
>> I do wonder why you have it set up this way, however.  Why do you control the flows this way?
>>
>> A
>>
>> --
>> Andrew Sullivan
>> ajs at crankycanuck.ca
> 
> 
> --
> Stéphane Schildknecht
> Contact régional PostgreSQL pour l'Europe francophone Loxodata - Conseil, expertise et formations
> 06.17.11.37.42
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-- 
Stéphane Schildknecht
Contact régional PostgreSQL pour l'Europe francophone
Loxodata - Conseil, expertise et formations
06.17.11.37.42