Re: [E] RE: dual active 2-node cluster?

Checkout AWS PostGres "Read Replicas".

.... Sushanta

On Mon, Apr 16, 2018 at 9:49 AM, Ron Watkins <rwatki(at)gmail(dot)com> wrote:

> What about a hot standby mode where secondary node is receiving all
> transactions in real (or near-real) time?
> Is this doable? We have 2 physical nodes, not 3, so if we can do a
> hot-standby config with a load balancer configured in fail-over mode, that
> should work as long as no transactions are dropped and the secondary node
> is staying current (i.e. dual commit) with the primary node?
> Does anyone know if there are any links to how to setup such a config on
> the web?
> Ron
>
> -----Original Message-----
> From: Laurenz Albe [mailto:laurenz(dot)albe(at)cybertec(dot)at]
> Sent: Friday, April 13, 2018 6:41 AM
> To: Ron Watkins; pgsql-novice
> Subject: Re: dual active 2-node cluster?
>
> On Fri, 2018-04-13 at 03:01 -0700, Ron Watkins wrote:
> > We are working to setup a production environment and as such one
> > requirement is to have as few single points of failure as possible. To
> > that end, I have been searching the web for how to setup a 2-node
> > cluster where both nodes are active. The goal is to allow both nodes
> > to service SQL requests (load/query) and have a load balancer in front
> of the database to allow for transparent outage and node recovery.
>
> You'd need synchronous replication, and if you do that with two nodes,
> you'll get low availability because any outage will take down the whole
> system. That's not a shortcoming, that's unavoidable.
>
> You need at least three nodes for decent high availability, particularly
> if you want load balancing.
>
> Look into Patroni for a high availability solution.
>
> Yours,
> Laurenz Albe
> --
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>
>

--

*Sushanta Saha|*MTS IV-Cslt-Sys Engrg|WebIaaS_DB Group|HQ -
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