High Performance NT4 Optimization and Tuning:Identifying Major Resources

Servers

Servers come in many flavors. There are, however, two basic types of servers: resource servers, which basically function as an extension of the client computer, and application servers, which provide specific services to a client computer. A resource server generally provides file and print services to its clients. By this, I mean that a client computer utilizes the disk drive and printers on the server as if they were physically connected to the client computer. An application server is not a server that shares programs like Microsoft Office. Rather, it is a server that provides a specific service. Your email server, for example, is an application server, as is your database server. Both of these servers provide a specific function (email or database) that utilizes the server on behalf of the client. For this reason, almost all application servers use a client/server design, where a portion of the shared application resides on the client and the rest of the application resides on the server. We will explore many of these server types in the upcoming sections. Let’s begin with a look at a resource server and see what resources it actually provides to its clients.

Resource Servers

The primary purpose of a resource server is to centralize resource management and lessen the requirement for standalone computers with large resource drains. You may have a computer you use to run a job once a week, for example. This program requires large amounts of disk storage for temporary files. While you can add additional disk drives to this computer to fulfil the job requirement, most of the time, this extra storage capacity goes unused. This underutilization of disk storage is where it begins to make sense to use the extra disk capacity of a resource server. If you place the extra storage on the server in this fashion, other network clients can use the additional storage space, as well. However, a resource server can provide many functions other than file and print services. It can also perform one or more of the following services:

• Authentication Server—All Windows NT Server domain controllers (primary or backup) are used to authenticate domain user requests to access resources on your servers, Windows NT, and Windows 95 workstations (if you configure your clients to use user instead of share-level authentication). An authentication server contains the client logon scripts, system policies, and user profiles, and performs the user authentication task by using the Microsoft Netlogon service.

• Browse Master—A browse master is a computer that maintains a list of computers and their associated resources. This list is used whenever a network client browses (such as when you use the Network Neighborhood) for a computer resource. On a domain, this list is only available to authenticated domain members. And the larger the list, the more resources (memory, network bandwidth, and so forth) are required.

Before you take your PDC offline, promote the BDC to a PDC. This will prevent having duplicate PDCs online when you place the old PDC (now a BDC) back online. This will also prevent the loss of user account modifications you made while the old PDC was offline.

• DHCP Service—The Dynamic Host Configuration Protocol service is used to automate the allocation and deallocation of IP addresses to DHCP clients. The DHCP service maintains these IP addresses in a Jet database (Microsoft Access database).

• DNS Service—The Microsoft Domain Name Server service is a proprietary implementation of the Unix DNS service. It maintains a static list of computer name-to-IP addresses for name resolution. It stores this information in various host files located in the SystemRoot\System32\DNS subdirectory. Or, if you have used the Microsoft DNS Administrator program located in the Administrative Tools program group, the static list is maintained in the registry.

• Gateway Services For NetWare—This service provides a gateway to access Novell NetWare server resources for your network clients. You can use this service to access a shared resource on your Novell server and then share it from your Windows NT Server. Then, all of your network clients can access the resource, even without a Novell user account. In effect, the Windows NT Server is a gateway to shared Novell resources because the client must go through the Windows NT Server to access the Novell resource. In the process, the client network data request must be converted from the Microsoft network data request format to the Novell network data format, and vice versa.

• IIS Services—The Microsoft Internet Information Server services include a World Wide Web (WWW) server, File Transfer Protocol server (FTP), and Gopher server. Each of these servers is used to provide a presence on the Internet or intranet to publish information.

• Routing Services—Windows NT Server includes the RIP for Internet Protocol and RIP for NWLink IPX/SPX services, which performs the same basic service as a hardware router. In either case, these services are used to pass data between one network data segment and another network data segment, using either the TCP/IP or IPX/SPX protocols.

• Remote Access Service (RAS)—The Remote Access Service is used to provide dial-in or dial-out access. You can use RAS to support external clients with a modem to access shared resources. Or, you can use RAS to connect to external resources (such as the Internet) and share them among your network clients.

• Remoteboot Service—The Remoteboot service is used to support diskless workstations. These workstations may be MS-DOS, Windows 3.x, or Windows 95 clients.

• Services For Macintosh—This service performs the same task as the Gateway Services For NetWare except that it is used to support Macintosh clients using the AppleTalk protocol rather than Microsoft network clients. Of more importance is the fact that this service provides the means for your Macintosh clients to access your Windows NT Server as a file, print, and application server, just as if it were a native Macintosh network server.

• Simple TCP/IP Services—This service includes various minor TCP/IP services (such as the Quotes service). The configuration files for these services are located in the SystemRoot\System32\Drivers\Etc directory.

• SNMP Service—The Simple Network Management Protocol service is provided to allow you to monitor and configure various Windows NT services remotely, using a third-party SNMP monitor application (such as HP OpenView).

• TCP/IP Printing Service—The Microsoft TCP/IP Printing service is used to provide print services of shared network printers on a Unix server to your Microsoft network clients or from your Microsoft network to your Unix clients.

• WINS Service—The Windows Internet Name Service service is used to provide dynamic NetBIOS name resolution (such as when you use a computer name to find a resource). It also maintains its information in a Jet database.

Most of these services are optional components you can install using the Network Control Panel applet. For each service you install (aside from the authentication and browsing services), you should add an additional 2MB of RAM to maintain your present performance. Of course, this is just a baseline. Any of these services that are used heavily might have higher demands for system RAM. What you should not do, unless you have no other choice, is run all these services on the same server, particularly on a server with only 16MB of RAM or limited storage space. It is possible to do so on a server with multiple processors, gigabytes of disk storage, and 64 to 128MB of system RAM. But even so, if a lot of clients utilize these services simultaneously, performance will suffer. At the very least, you should separate your IIS services and place them on another server, particularly if this server will be used in a commercial or high-traffic environment.

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