Java Reference
In-Depth Information
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Platform-Dependent Data
Properties in this group are used for platform-dependent AH
installations, for example; or in a low-level context, such as with Java-enabled embedded
devices.
N
OTE
The location where this data is kept is not necessarily on the client-side. Depending
on the particular domain, some or all of these properties could be stored on the
Deployment Server or somewhere else.
AH Costs
The AH offers deployment services to the launched application, but these come at a cost. With
the term
cost
, we mean here both resources and time costs, but mainly the latter, in a user-ori-
ented perspective. The more striking cost, as perceived by the user, is the total launch time,
especially for the first execution, when we assume there's nothing yet installed on the client
platform (refer to Figure 2.8). In the following count, the JVM installation time is thought of
as being part of the AH Installation Time, together with the distribution time.
Total Maximum Waiting Time at Application's First Launch =
AH Installation Time +
AH Launch and Resolution Time +
Application Installation Time +
JVM Launch Time +
Application Launch Time.
Let's discuss this briefly.
•As we know, there are some fixed costs when deploying and generally running Java
code. The JVM and the application launch times cannot be shortened by any deployment
techniques.
• The total amount of time for the very first installation could be quite high, so there is a
real need to cut it down in some way. The technique more commonly used in these cases
is to split this sum, separating the processes of AH Installation from Application
Installation (refer to Figure 2.5) that are the biggest addenda in this simple formula.
Summing up all the times we run the application, the previous count becomes as follows:
Total Maximum Waiting Time at Application's First Launch =
AH Installation Time +
Application Installation Time +
