Java Reference
In-Depth Information
We will isolate a set of standard features that will guide us through the specification of our
deployment requirements. We will begin from the abstract model for Java software
deployment.
In Chapter 2, we devised several phases that can be seen as features that the deployment circuit
can provide to its client applications. Particularly, we focus here on the following services
(among those discussed in Chapter 2):
• Application Installation
• Application Management
• AH Application Support (excluding On-The-Run Management)
• AH Management
• AH On-The-Run Management
Note that these services are ordered on the basis of their occurrence in real-world deployment
circuits. One can think of the Application Installation service as the barest of all the deploy-
ment services. Then comes the capability of updating the installed software (Application
Management) and so on. Furthermore, commercial deployment solutions tend to offer a coher-
ent set of features. Hence, we can think of such a ordering implying the inclusion of all the
preceding services (ranks 1, 2,…, n-1), together with the given one at rank n. That implies, for
example, that those deployment circuits offering some AH management services, supposedly
offered in various forms, also offer Application Installation, Management, and basic AH
Application Support services as well.
Of course this ranking is arbitrary; in some special cases, we could have a deployment circuit
featuring application installation and some AH On-The-Run Management services only, with-
out any Application Management. Nevertheless, we are interested in a practical set of standard
services applicable in the most common cases.
4
This list could be useful for guiding us through the design of general-purpose deployment cir-
cuits, but it is rather ineffectual in most daily deployment tasks. To follow the line of the prac-
tical approach, let's specify better our standard services. Although the previous list of services
is quite complete, it is still too abstract. We solidify it in the following (ordered) list of deploy-
ment features:
• One-Shot Installation. Corresponds to the basic job done by any installer utility, com-
prised in the Application Installation Phase. We assume that every deployment circuit
provides such a feature.
• Automatic Updates. The most common service in the Application Management Phase is
the capability of updating installed applications seamlessly.
