A domain is not related to cluster, it is a management thing.

If you configure a server-group, that mean a bunch of servers with the same configuration (like if you copy the standalone*.xml to different standalone instances)

I'm not sure about the HornetQ <backup>, if you can set an instance as backup you need to add this to a different server-group and use a copy of the profile (with changes)

If there is only one attribute to change, you might use an expression like "${my.boolean.setting:false}" if the property is able to handle it will use my.boolean.setting and if not available default to false.

You are able to set such properties in the host.xml <server><property> elements

Yes, a server is a server and the domain-controller is a management instance without any application function.

So you need apache (or other LB) in front of the servers.

If you use a static protocol you need to add all the servers to apache, a better approach is advertizing like mod_cluster, here the server know where the LB is and send a request to be added/removed from it.

No there is no maximum of hosts/servers, you can add as many you want, but I think it get complex if you have a lot of different configurations

Make sense to you?

Are all the deployments on all the nodes? In that case I don't see a need for multiple balancers. Each server can register multiple /contexts with each balancer.

Where you able to resolve your issues?

I don't understand how are you configuring a server-group containing multiple servers which are running in more than one physical servers? I don't see any article explaining this. I would appreciate if you can share the configurations.

  <servers> 
     <server name="server-one" group="main-server-group"/> 
     <server name="server-two" group="main-server-group"> 
          <socket-bindings port-offset="150"/> 
     </server>

    <server name="server-three" group="main-server-group"> 

          <socket-bindings port-offset="150"/> 

     </server>
  </servers> 

I want to configure server-two and server-three are running in two different physical machine. Ultimately I want to configure all 3 servers under servers need to run on 3 different physical machines. Is that possible? If so how?

Hello Joseph,

you need to distinguish between the domain configuration (domain.xml) which is only necessary for the domain-controller. This include the profiles and the server-groups.

And the host.xml which is the configuration for each  which is for the domain-contoller and all slave host-controller.

So you start a domain-contoller with all configuration, you can add servers here, but it is recommended to use the DC only for administration and without app-servers see host-master.xml.

Now you start another instance (with domain.sh) but change the host.xml to connect a remote DC (example slave-host.xml), this HC will connect the DC and pull the configuration.

Within the host.xml you are now able to add servers and align it to a server-group, and this for all instances, as many you want or the domain network can handle

That's it

Thanks for your response Dieter Fink.

I understand Domain controller & Host controller concepts. I am also planning Domain Controller is just for managing HostControllers. My question was The servers inside the ServerGroup can be set up on more than one machine or not?

For example I have I have 5 physical machines. Machine #1 is acting as a DomainController. Machine #2 is a HostController(just only one HC). I am creating just only one server-group. This server group need to handle Machine#2 (HC), Machine#3, Machine#4 and Machine#5 servers. I mean to ask whether the servers inside a server-group can be deployed on more than one machine or not? If not How should I go about this? 

The server-group is the 'parent' for servers, just to inherit configuration and configured in domain.xml

If you want a server to join the server-group (only one allowed for a server) you simple need to add a new server element for a host (no matter which host).

This can be done by edit the host.xml at the machine you start the slave or using the management console (here the HC need to be started and connected to the domain first - maybe without any server configuration)

So yes, servers in one server-group can be on any host-controller of your domain and a host-controller can be started on the same or different physical machines as the domain contoller.