21. Directory-Enabling ExistingApplications
| Understanding and Deploying LDAP Directory Services > 5. Defining Your Directory Needs > Analyzing Your Environment |
Analyzing Your EnvironmentTo accurately determine your directory needs, it is essential to understand the environment in which your directory service will operate . Unless you are new to your organization, you probably already know quite a bit about the overall environment. Spending some time during the early stages of design to record what you do know, and additional time on research to fill in any missing details, will pay off later in the directory design process. Explore the eight areas described in this section to help you produce a complete portrait of the environment in which your directory service will be deployed. Organizational Structure and GeographyCreate a list of the major units within your organization and all the physical locations your directory service must serve. Note significant differences about the environment at each location and refer to them as you proceed with the remaining environment topics. For example, some locations will have more users than others, different kinds of computer systems, better network connectivity, and so on. Organizational structure and geography will influence everything from how many physical servers you need to deploy to how you maintain the data stored in your directory service. The needs of a small organization located in a single building are generally simpler than those of a multinational organization with offices located in many different time zones. In the latter case, seemingly simple decisions, such as choosing a time of day to perform system maintenance, are difficult because of the multitude of time zones in which the users of the system live and work. The amount of independence that individual departments within an organization have varies widely from organization to organization as well. In a decentralized organization, it may be appropriate or perhaps even required that you delegate responsibility for directory content to each department or location. In a centralized organization, management of the directory may be centralized for better efficiency. Computer SystemsCreate an inventory that characterizes the different types of computers that exist in your organization. Also record approximately how many of each different type are in use and the role of each system. A sample computer system inventory is shown in Table 5.1. Table 5.1. A sample computer system inventory
You should also consider the following system- related topics:
If you are a system designer, administrator, or other information services (IS) professional, you already know how important it is to understand what computer systems are used in your organization. The variety of systems that must be supported by your directory service constrains your choices for directory server and client software. In some cases, the systems in use provide a hint of your users' expectations. For example, if most of the computers installed on their desks are high-end PCs or workstations, they will expect your directory to be fast and responsive too. The NetworkObtain or create a map of your organization's network (or the portion of it on which your directory service will be deployed). This map should show all the backbone and branch networks that exist in the part of your organization your directory service will serve. Each network link should be labeled with information about its bandwidth, latency, and reliability, along with any usage-based costs. In large organizations, there is usually a central group that oversees the network; hopefully, this kind of information can be easily obtained from them. If necessary, you can measure the characteristics of the link or simply estimate based on the technology employed. A sample network map is shown in Figure 5.1. Figure 5.1 A sample network map. The network shown in Figure 5.1 is generally very good except for the intermittent ISDN line that links the Vancouver office to the main campus in Mountain View. When designing your directory service topology, special consideration should be given to any part of the network that is particularly weak. For example, it may be necessary to place a directory replica in the Vancouver office to provide good service there. All directory services depend on a computer network to exchange data with applications and for communication between the directory servers themselves. The composition, speed, and reliability of your network will heavily influence how many servers you need and where best to locate them. The network may partially determine how many users and applications your directory can serve. Finally, in some cases the characteristics of the network may limit the types of directory applications you can support. For example, because most messaging systems employ store-and-forward designs, a messaging server can usually tolerate some delay in receiving responses from a directory service. In contrast, people who use an online phonebook application are unlikely to tolerate delays that exceed a second or two. To the messaging server high throughput is very important, but to end users low latency (response time) is very important. The network between the directory server and the applications or end users is one factor that influences the overall throughput and latency of a directory service. Application SoftwareIn most organizations there are typically a large number of different application software packages in widespread use. For planning purposes, concern yourself with only the most popular, the most critical, and the directory-enabled applications. Much of the design of your directory service will in fact be driven by the needs of the directory-enabled applications you plan to deploy. These needs are discussed in more detail in the next section of this chapter and in Chapter 6, "Data Design." UsersIt has been said that there are only two businesses that refer to customers as users : the illegal drug trade and the computer industry. Regardless of what that saysabout the computer industry, the term is widely used and is generally well understood . In the context of directory services, it refers to all the people who use a directory service or an application that depends on a directory service. It is essential to know how many users you are serving, who they are, where they are located, what different categories they occupy, and what their expectations are. Successful computer professionals know that their primary mission is to meet and exceed users' expectations. Users' needs are discussed later in this chapter. System Designers and AdministratorsWe use the term system designer to refer to a person who designs and plans for the deployment of information systems. A system administrator is someone who is responsible for the care and maintenance of a production service. When planning your directory service, the most important system designers whose needs must be considered are those who design and plan the deployment of the directory service itself. Similarly, the most important system administrators whose needs must be considered are those charged with running the directory service. The characteristics of the system designers and administrators lead to a set of deployment constraints that may affect your approach. Deployment constraints are examined in more detail later in this chapter. The Political ClimateGeographical boundaries and organizational structure often lead to differences in thinking among groups. Political climate is an important but often misunderstood aspect of an organization's environment. Because political differences often occur due to lack of communication between groups, they tend to be more pronounced in large, mature, or hierarchically managed organizations. Tip You will probably find it difficult to paint an accurate picture of the political climate within your own organization. The best approach is to ask some experienced employees from a variety of organizational units for their own views and look for common themes and complaints. You will still need to sort out fact from fiction , of course. Political disagreements are usually centered on how to use resources (people, money, time), the direction of the organization as a whole, or philosophical differences between managers. These disagreements may hurt your directory service deployment efforts if you get caught in the middle. We examine politics again later in this chapter when we discuss deployment constraints. ResourcesResources include all the scarce commodities that limit the amount of work that can be accomplished. The most important resources are people, time, and money. Resource-rich organizations tend to do things on a larger scale; of course, expectations of those working in such an environment are high as well. In contrast, if you work in a resource-poor organization, you typically are held accountable for all expenditures, and you may have to do more work up front to show that your directory service project will pay for itself. No matter what kind of organization you are associated with, your directory deployment project will be expected to show a good return on investment, so it is important to use resources wisely. We discuss resources again later in this chapter when we discuss deployment constraints.
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Index terms contained in this sectionadministratorssystem directory environments analyzing directory environments applications software directory environments computers inventories directory environments 2nd defining directory needs environments directories needs environments environments directory needs geography directory environments inventories computer directory environments 2nd maps network directory environments 2nd needs directories environments networks maps directory environments 2nd resources directory environments software application directory environments systems administrators directory environments inventories directory environments 2nd users directory environments |
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