Package Localization
Introduction
It is rare that software can be installed on
a system and work without any modifications. Most software needs
to have some sort of awareness about its environment; the machine
it is running on, the user it is running for, and the site
policies it needs to follow. We refer to these modifications as
localizations because the changes are due to local organization,
site, or host machine requirements. This paper defines terms to
identify sources of localization and the various stages when
localization occurs.
Localization Sources
Here are the types of sources that
provide localization data:
User
Many applications will allow users to tailor there
behaviour. These "user preferences" are a form of localization.
Virtual Organization
Virtual organizations in a Grid
environment are discussed in this paper. For
our purposes a virtual organization is a group of users who are
using resources at a number of independently site adminstered Grid
locations. An example of this is the NEESgrid. Virtual
organizations would like to have software at the different sites
to operate consistantly ahd nave an awareness of the organization.
For example, virtual organizations may want to set up a
meta-directory service that serves as a central location to
publish grid resource characteristics. This service can then be
used by both users and applications to locate group resources.
Site
Most IT organizations have policies regarding
security, port usage, etc. which needs to be followed by
installed software. In addition, sites may use several remote
administration tools such as centralized account management which
will also affect the localization data. A more specific instance
of this is clusters where a group of machines (nodes) are managed
as a single unit. In this case the remote administration is more
intrusive.
Host Machine
Software needs to the know the
characteristics of the machine it is running on.
When Does Localization Occur
There are several different
points during the deployment of the software when localization can
occur.
Before Runtime
The localizations can occur before the
software executes.
After Installation
Most package managers (including GPT)
have a post package install stage that allows localization scripts
to be installed.
Before Installation
For GPT, most software is deployed
using bundles. The localization can
be done when these bundles are created.
Localization What and When
Here is a table showing what
type of localization occurs when:
| Type |
Pre-Install |
Post-Install |
Runtime |
| User |
|
|
X |
| Virtual Organization |
X |
|
X |
| Site |
|
X |
X |
| Host |
X |
X |
X |
Notes about the table.
- User localization should ideally occur at runtime since most
Grid software supports multiple users.
- Virtual Organization localization should also occur at
runtime since these organizations is by definition temporary.
However there is some utility in having virtual organization
deploy localized bundles.
- Host localization during pre-install makes sense for cluster
software deployments where node specific bundles are assembled
at a central location.
Summary
This page defined some terms that allows for a
more precise discussion of software configuration. But this is not
the complete story. Another essential part of localization is
choosing what software needs to be installed. Look at this page for that discussion.
Last modified: Mon Mar 18 20:02:09 Central Standard Time 2002