Java Reference
In-Depth Information
•
Host Controller
: It is a process that is responsible for coordinating the
lifecycle of server processes and the distribution of deployments from the
domain controller to the server instances.
•
Application server nodes
: These are regular Java processes that map
to instances of the application server. Each server node, in turn, belongs
to a domain group. Domain groups are explained in detail when we dis-
cuss the domain configuration file.
Additionally, when starting a domain, you will see another JVM process running on
your machine: this is the Process Controller. It is a very lightweight process whose
primary function is to spawn server processes and Host Controller processes, and
manage their input/output streams. Since it is not configurable, we will not discuss it
any further.
The following diagram depicts a typical domain deployment configuration:
As you can see from the preceding screenshot, one host (
Host1
) acts as a dedicated
domain controller. This is a common best practice adopted in domain-managed serv-
ers in order to logically and physically separate the administration unit from the serv-
ers where the applications are hosted.
The other hosts (
Host2
and
Host3
) contain the domain application servers, which
are divided into two server groups:
main-server-group
and
other-server-group
.
A server group is a logical set of server instances that will be managed and con-
figured as one. Each server group can in turn be configured with different profiles
and deployments; for example, in the preceding domain you can provide some ser-
vices with
server-group-one
and other services with
other-server-group
.
