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Chapter 1: GroupWise Architecture: Basics
This chapter examines the Novell GroupWise architecture. It defines some terms, briefly discusses the ways that certain components interact, and prepares you for a more thorough discussion of architecture in the chapters that follow. A discussion of the evolution of the GroupWise product is also included to help you understand some of the naming conventions used.
Terminology and a Basic GroupWise 5.5 System
The word GroupWise is a Novell, Inc., trademark. It refers to a collection of applications and data stores that, taken together, provide email (and a lot more) to a community of computer users. GroupWise is properly categorized as collaboration software or as a "groupware" product (Figure 1-1).
The term GroupWise User, or sometimes just user, refers to a mailbox that has been assigned to an end user on a GroupWise system. If we use the U.S. Postal Service as an analogy, a GroupWise user is similar to a post office box. Just as various mail items are delivered to a post office box, email and other items are delivered to a GroupWise user.
GroupWise Post Office
Just as a post office box exists at a U.S. Postal Service post office, a GroupWise user exists at a GroupWise post office (Figure 1-2). A post office also may contain resources, libraries, and other GroupWise objects, but we'll get to those later.
Physically, every GroupWise post office exists as a collection of directories and data files on a file server. One of the most important attributes of a post office is the path to the root of these directories, the UNC(Uniform Resource Name) path, as shown in Figure 1-3. GroupWise Domain
If GroupWise users are like post office boxes and GroupWise post offices are like U.S. Postal Service post offices, then the GroupWise domain is like the distribution center at an airport, where trucks shuttle mail to various U.S. Postal Service post offices. At this point, the analogy gets a little difficult to follow, so we'll talk about domains in terms of their functions. Domains exist to
- Transfer items between GroupWise post offices
- Transfer items to other GroupWise domains (which, in turn, deliver to their post offices)
- Provide a point of administration for all GroupWise objects, such as users, post offices, and libraries (Figure 1-4)
Although post offices are where most of the action is, GroupWise domains are necessary because post offices cannot be administered by themselves. Just as we saw with post offices, every GroupWise domain has a physical location, or UNC path. This domain directory is the root of a complex directory structure containing files that are critical to the administration and proper functioning of a GroupWise system (Figure 1-5).
Primary Domain Every GroupWise system must have a GroupWise primary domain. There can only be one primary domain in a GroupWise 5.5 system. All other domains established within a GroupWise system are either secondary domains or external domains. The first domain you create in a GroupWise system will be your primary domain.
The primary domain can function like any other GroupWise domain, with post offices, users, etc. The difference is that the primary domain is the supreme authority within a GroupWise system (Figure 1-6). This means that any change made from any domain in a GroupWise system must be cleared through that system's primary domain. The GroupWise primary domain is responsible for replicating changes to all other domains, and in the event that a secondary domain database is damaged, the primary domain can be used to completely rebuild that secondary.
Secondary Domain Most GroupWise domains are secondary domains. They function as described above under "Domains." When a change is made from a secondary domain, that change must be transmitted to the primary domain before it can be replicated to the rest of the GroupWise system (Figure 1-7).
Mail messages do not move in this manner. Secondary domains do not need to route ordinary mail messages through the primary domain. Only administrative changes must be routed in this way.
The GroupWise System
The very top-level component of GroupWise is called the GroupWise system. It is not a true component, however, in that it does not have its own directory structure or even its own object screen like domains and post offices do.
The GroupWise system is basically the name assigned to the collection of domains, post offices, and users (and more) that are managed from a particular primary domain. The system is represented by the icon shown in Figure 1-8.
The GroupWise client. is an application that allows a computer user to access a GroupWise mailbox. There are several GroupWise clients, the most popular of which is the GroupWise 5.5 32-bit client for Windows 95/98/NT (see Figure 1-1). This GroupWise client typically talks to a Post Office Agent (POA) in order to access the mailbox.
Every GroupWise 5.5 post office must have a Post Office Agent t POA) associated with it (Figure 1-9). A POA is a software process that typically runs on the same file server that houses the GroupWise post office (Figure 1-10). The POA updates user mailboxes on that post office. A GroupWise POA also updates its GroupWise post office with administrative changes made from a domain in the GroupWise system. These updates may be address kook changes or changes relevant to end users' interactions with the GroupWise system, such as rights to libraries or membership in distribution lists. The POA will be discussed in detail in Chapter 8...