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1. Producer to Distributor Publication This is an internal publication, for Deployment
Servers only. The Deployment Policies and annotated Resources (seen previously in this
chapter) are released in this phase.
2. Distributor to End-User Publication This step takes the Deployment Policies and
Annotated Resources output of the preceding step as input (they are arranged in rigid
sequence in the model). As an output, it produces the resources ready to be deployed by
AHs wherever they are installed. Basically, the job of the Distributor in this initial phase
is to “understand” the language spoken by the Producer, in order to enforce it with
AH Installation
During this phase, the AH is installed itself. That is, it is registered permanently into the under-
lying platform environment as an executable. It is composed of two successive steps:
1. AH Distribution The AH is distributed as another resource. For simplicity, the server
from where the AH is downloaded is thought to be the Deployment Server for normal
application resources.
2. AH Physical Installation After having completely transferred onto the client platform,
the AH itself must be installed. In order to do so, this phase is usually carried out by end-
users, system administrators, or less-sophisticated installer facilities.
Deployment Server Management
Represents the management of the Deployment Servers made by the Distributor. This can
include replication, load balancing, updating, redundancy configuration, and so on. Our model
is focused on the client aspects of deployment, so we won't refine this step any further. Indeed,
this is an important phase, but it is beyond the scope of this topic.
AH Check-Out
This is conceptually an important phase in our model regarding the client side of the deploy-
ment process. The decisions taken by the AH are gathered in this phase. In the lifecycle pro-
posed in Figure 2.5, all the phases reached by the AC Check-Out stage must be thought of as
being linked with an arc back to this phase in a sort of never-ending execution loop, until the
AH exits or it is shut down. Those arcs are not represented graphically for visual cleanness.
The objective of this phase is to decide which action the AH has to perform on behalf of the
client application and the given Deployment Policies.
This stage is composed of two successive steps:
1. AH-DS Connection A connection with the Deployment Server is established by the AH
or, less commonly, vice versa. When this connection cannot be carried out, the AH can
decide what to do using other strategies. Basic policies could be hard-wired in the AH
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