How to set up Topology Manager to publish contents to multiple servers

Question

I have multiple Web-AP server on live environment for fault Tolerance.

So I want to publish contents to multiple servers at publishing time.

I set up Topology Manage as following(I have two Web-AP servers "Server A" and Server B).

[CDEnvironment]

ID           :ServerAEnvironment
Discovery URL: http://ServerA/discovery
Purpose      :Live

ID           :ServerBEnvironment
Discovery URL: http://ServerB/discovery
Purpose      :Live

[CDWebsite]

ID             :ServerAENWebsite
CDEnvironmentID:ServerAEnvironment

ID             :ServerBENWebsite
CDEnvironmentID:ServerBEnvironment

[CDMapping]

ID             :ServerAENMapping
WebappliationID:ServerAENWebsite_RootWebApp
Publication URI:tcm:0-1-1

ID             :ServerBENMapping
WebappliationID:ServerBENWebsite_RootWebApp
Publication URI:tcm:0-1-1

(ServerAENWebsite_RootWebApp and ServerBENWebsite_RootWebApp are created automatically)

But error occures at creating TTMMapping.

The error message says that "combination of CMEnvironment and Purpose and PubicationURI have to be unique".

Also it's impossible to map multiple TTMWebApplication to one TTMMapping

(Like Mapping both ServerAENWebsite_RootWebApp and ServerBENWebsite_RootWebApp to "ENMapping")

It's common scenario that Live environment have multiple servers and publishing contents to those servers.

How to achieve it by Topology Manager?

Regards,

Answer 1

The Environments (and Websites/apps) you configure in Topology Manager represent logical Environments; each of these things may or may not be scaled out physically, but that doesn't affect Topology Manager.

In your case, it seems you want to scale out both your Websites and your Deployer. The idea is that this is achieved at the infrastructure level.

For example: the scaled out websites could be behind a Load Balancer and you configure the Load Balancer's URL in Topology Manager. Alternatively, you may let your DNS server do round-robin IP address resolution and ensure you use the DNS name in the Website URL in Topology Manager.

Scaling out the Deployer is trickier, but can be done in an Active/Passive ("failover") configuration. Again, the idea is that you use NLB to achieve this and configure the NLB's URL for the Deployer Capability.

If you want to mirror your CD databases (e.g. for Disaster Recovery or geographical load balancing reasons), you can use your RDBMS's mirroring facilities.