Apply WIN2000 to create a web cluster server that supports enterprise-level access
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As a multi-erasable operating system that Microsoft's fully launched, Windows 2000 goals are to completely changing the user's business model, quickly establish a business enterprise-class Internet information system. Internet Information Services 5 provides a powerful feature as the core part of the Windows 2000 network information service. How do I create a web site that supports corporate levels of users? For enterprise-class users accessing requirements such as e-commerce websites and ISP customers, the best way to ensure the availability and reliability of the service is to establish a web cluster server. For this problem, Windows 2000 Advanced Server provides a good scalability service. The web cluster is a Web site consisting of any multiple computers. When the designer creates a Web cluster, you can select a three-layer web architecture (consisting of web server programs, COM applications, and database applications). The advantage of the three-layer architecture is that the designer can disperse the following levels of tasks to different servers, rather than combining them on a server:? Representation layer: Publishing content? Business logic layer: Run application? Data layers: Accessing the database Use several low-cost servers, designers can easily handle a large number of customer requests without any unnecessary delay. Sharing loads between multiple computers are critical to enterprise users support heavyweight applications: for example, handle financial transactions, access databases, support company intranet, and implement other important daily activities. I. Two important terms related to Web clusters are: clusters and load balancing. The following will briefly introduce these terms the meaning of the Web cluster. 1. Cluster clustering means that the group division does not interdependent, and a batch of servers managed by managing a single system. The minimum requirements for a server cluster are as follows: • There are at least two (or multiple) networking servers? Cluster management software, such as Network Load Balancing, or Cluster Service Cluster management software. These cluster software perform the following tasks:? Detect which computer in the cluster is faulty? Recover the system from any fault or server overload? Balance the request load on all servers in the cluster? To manage this batch of servers as a single system Bring the server cluster into a system, with the following advantages: I always handle the request. Because requests from the customer can balance allocation between several servers, it reduces the possibility of a server overload. If a server overloads or fails, the load balancing can be allocated on the rest of the server, so that the customer's normal access is not interfered. • Easy to manage. You don't have to manage each server separately, and administrators simply manages them as a unit. • Biggasibility. Designers can easily add more servers to the cluster, or upgrade to existing servers, and this does not interfere with the customer's request. 2. Load balanced load balancing refers to allocating a customer request equal to multiple servers in a web cluster. Generally, load balancing can increase system throughput rate while maintaining a lower response time. By using NetWork Load Balancing embedded in Windows 2000 Server, the host can detect each visited IP packet, which only receives it in accordance with the receiving condition. Each Network Load Balancing host can specify a percentage of packets that will be processed. As an option, the message can also be assigned equal to all hosts. If a host is faulty, the load balancing mechanism will reassign the packets between the remaining hosts.
By using the scalability provided by Network Load Balancing, administrators can upgrade existing servers or add new computers to the cluster when demand is increased to handle more IP traffic. Second, WINDOWS 2000 Advanced Server Group Load Balancing Features We will describe the load balancing features provided by Windows 2000 Advanced Server: Network Load Balancing and Cluster Service. NetWork Load Balancing and Cluster Service can enhance any security reliability. Grouping them is a powerful way to combine backend databases and transaction systems with web-based front ends to effectively provide the scalability required to users, high availability of customers. Each solution is briefly listed below and gives how to integrate them into a three-layer configuration: • NetWork load balancing balances those that are mainly generated by the entry TCP / IP communication. Administrators can establish Network Load Balancing on the first floor and balance the site access on the cluster's web server. • Cluster Service is an ideal choice for grouped those database services that require high availability, which can be Microsoft SQL Server 7.0 or other data sensitive applications. Administrators can establish Cluster Service on the Layer 3 to complete tasks such as user accounting and database purchase. Third, create a three-layer web cluster combines these two load balancing characteristics, which will be ideal for three-layer architecture applications. For example, if an e-commerce website installation uses a web-based retail service, you can establish the following clusters: • Establish the front-end, user interface (UI) layer on multiple servers, using NetWork load balancing to balance and allocate customers TCP / IP connection. When the amount of traffic is increased, the existing cluster is upgraded or adding a computer to the configuration. This ensures that the site is able to handle access requests. • Use the Cluster Service to provide node fault takeover functions for the application and the data service layer of the application and the three-layer application. This will create a reliable platform for databases, messages, and similar applications. Since all three levels are stored on a single server website, this topology will introduce some new concepts. Figure 1 shows a feature of an example web cluster, wherein the arrow indicates how the content is copied. Figure 1 Example Web Cluster Server Structure The following will exemplify how to create a web cluster server. 1. Computing Hardware Requirements In order to establish a web-based retail business, designers need to determine how many web servers actually need to meet a specific application. It can be started from one server, and it will be upgraded after it is necessary. After testing a single server, the designer may find that the utilization rate of the server CPU is particularly high, and the cache hits is very low and there are many requests in the queue server. At this point, system performance can be added by adding processors, memory, and other hardware devices. If these solutions do not improve performance, you can consider adding additional web servers. Since there is no ready-made mathematical formula for determining the optimal number of servers that need to be added, the designer can choose from multiple web test tools to help determine the optimal number of servers. Among them, a tool is a Web Application Stress Tool that allows the designer to simulate the situation of thousands of user loads on the test site. Combined with the System Monitor tool, the designer can easily determine the load limit of a single web server. The main bottleneck of the web server is HTTP layer, in order to break the bottleneck, the designer should increase the web server.
After testing a single server, the designer may decide to upgrade so that the user's web access request can be effectively processed. For example, two web servers can be added to form the first layer of the web cluster. 2. Creating the first floor With the addition of two new web servers, the designer must now balance the request load between these three servers by running Network Load Balancing. Three servers are just a server from the customer's perspective. Because the designer only assigns an IP address to three servers in a cluster, the management cluster is very easy. By configuring a DNS server, the designer can establish www.example.com using IP address 192.16.1.10. The IP address represents all hosts in the cluster (three servers at this time). For how to assign an IP address, refer to the "Configure TCP / IP Settings" topic in the Windows 2000 online document. With this configuration, the designer can change the site topology from a web server to three. You can now use the Web Application Stress Tool to test the application again, and you will see performance improvement immediately. Next, test the cluster again, but this time you have to use thousands of users to simulate, confirm that the resource consumed by the site is much smaller than the resources consumed by the single computer running IIS 5. If the application requires higher availability, you can add more hosts to 32. In addition to creating a cluster, another way to improve reliability is tobontact developers from developing products on a web server. By establishing a development server (such as dev.example.com), the designer can publish content and test its application on this server. Then you can hand over all authorization and development to the server. If the designer is installed on the development server (dev.example.com) installed FrontPage Server Extensions, users can use FrontPage to connect to a development server, write content, and create applications without having to introduce the application into the web product server. on. Once the data is ready for the product, use the Content Deployment feature of Site Server 3.0 to copy the data from the phase server to the Web server product. The unit that must be copied between the three web servers is the web content. When the designer needs to copy data, Content Deployment will easily implement the process, so that you can save a lot of time. When the site size increases, you need to set a separate log file for each server. If three servers are in the same Web cluster, three separate log files must be analyzed, and all logs can be imported into a source to help simplify tasks. Site Server USAGE Analyst provides a simple way to import these files into a source, and the designer can generate custom reports to represent all traffic on the Web site. To achieve higher reliability and availability, you can add another cluster and limit it on your business content customers. In Figure 1, the cluster is called premium.example.com. The strategy here is to convert the urgent business request to premium.example.com, and use www.example.com for a general public service. Once the designer adds a server, the development server is created and simplifies the log, it will notice that the site is very complicated. In order to handle additional complexity and the number of applications, the designer may need to create other layers to maintain the validity and performance of the Web site. 3. Creating a second layer When the ASP application is combined with Windows 2000 components, the site will soon become more complicated. The ASP application can be considered to connect to the intermediary of the application and data service layer. ASP provides a rich and powerful development environment.
But if you really want to increase the overall performance of your application, you should consider adding COM components. Use the ASP application to call a component that contains user service logic, which resides on the second layer of application server. An application server can be simply a Windows 2000 Server, which is primarily a processor feature. At this point, the ASP application resides on the first layer web server calls the second layer application server to handle business logic. A portion of this process will request assemblies to extract data from the backend database located in the third layer. 4. Creating a third layer In order to obtain high availability on the third layer, the designer needs to install the Cluster Service. In order to store backend data that make up the third layer, most enterprise users need a high-end symmetrical multiprocessing (SMP) server (for example, a 8 processor SMP with 4GB RAM) To run a large relational database such as SQL Server 7.0. Cluster Service can handle task urgent database management, files, and intranet data sharing, message mechanisms, and generic business applications. It is best to add a server for troubleshooting, not just a high-end Windows 2000 Server. For integration, these two servers provide higher availability for access requests and simplify management data and applications. Cluster Service not only allows designers to connect two servers into a cluster, but also automatically detect and restore server and application failures. In addition, it can subtly handle the workload of the server to make the administrator to maintain the program without closing the server. Cluster Service has a built-in mechanism that can handle the server's failure. If the Cluster Service detects a server failure, it automatically transmits the relationship between resources (such as disk drives, and IP addresses) from one fault server to another normal server. Then it restarts the workload on the failed server on the normal server. From detecting a failure to restart another server, it is usually less than one minute. If a separate application failure (but the server is not faulty), the Cluster Service will try to restart the application on the same server. If it still fails, the Cluster Service transfers the resource of the application to another, and restarts the application on the server. For more information about Cluster Service, please refer to Windows 2000 Advanced Server online documentation. 5. Summary now can now summarize the creation of the entire website. In this example, the designer can start from a single IIS 5 web server where all necessary things can be completed. Since the user's application requires high availability, scalability, and performance, the designer can create a three-layer web architecture and use Microsoft Technology with high availability for each level. Then you can use the Web Application Stress Tool test a single server and implement it. To achieve higher availability, you need to create a web cluster. To this end, three servers should be calculated first. Then install Network Load Bulance, and these three servers are essentially as a server. Next, the designer should add the fourth web server as the development phase server so that the user can publish the content to the server. In order to copy the developed content, the designer should use the Content Deployment feature of Site Server 3.0 on the stage server and web server products.
