What is a web garden? Maximum number of working processes (IIS)

IIS 6.0 allows the application pool to be configured as a Web Garden. To understand the concept of Web garden, imagine a scenario where you have an IIS 5.0 server and three Web sites, each running the same application, if IIS 5.0 can automatically request in a circular loop mode. Send them to these functionally equivalent, virtually separate Web sites, and separate the load into three different processes to form a small Web Farm —— this is the Web Garden.

In the IIS 6.0 Web Garden, we don't have to create additional Web sites, just specify the number of worker processes for an application pool. The specific configuration steps are: open the application pool's "Properties" dialog box, go to the "Performance" page, enter the process in the "Maximum number of work processes" under " Web Garden" The quantity is shown in Figure 8. When the server load is small and no additional work processes are required, IIS 6.0 automatically reduces the actual number of worker processes after a certain amount of time (default 20 minutes, configurable); if the load becomes larger, additional work processes are required, IIS 6.0 again increases the number of work processes. All of this is done automatically and requires no administrator intervention.

Web Garden: In the Web Garden you can configure the maximum number of working processes used by this application pool. The default is 1, the maximum can be set to 4000000; the configuration uses multiple worker processes. You can improve the performance of the application pool processing request, but before setting up to use multiple worker processes, consider the following two points:

Each worker process consumes system resources and CPU usage; too much Worker processes can cause a sharp drain on system resources and CPU utilization;

Each worker process has its own state data. If the web application relies on the worker process to save state data, it may not support multiple uses. Work process.

Q: IIS 6.0 has a new feature called Web Garden, which allows you to configure your application pool to use multiple worker processes. When does IIS create additional worker processes? What should we know before we implement the Web Park?

A: When you create an application pool, you are notified that IIS 6 creates a worker process to transfer the content of the Web sites, files, and folders assigned to the application pool. You can configure the application pool to start multiple instead of one worker process, which can improve scalability. This feature is called Web Garden and is a small "Web Farm". Instead of using multiple computers to deliver the same content (Web farm), you can use multiple processes from one computer to deliver the same content.

When IIS 6 application is configured for Web garden, you need to & ldquo; the application pool properties & rdquo; of & ldquo; performance & rdquo; tab & ldquo; the maximum number of work processes & rdquo; box, Set a number of worker processes greater than 1. If this value is greater than 1, each request will start a new worker process instance, and the maximum number of processes that can be started is the maximum number of worker processes you specify. Subsequent requests are sent to the worker process in a round-robin fashion.

Web Garden is very useful when your application resources are limited. For example, if your connection to the database is slow, you can use multiple worker processes to increase user throughput and thus increase the number of connections to the database.

Although in some cases the use of the Web Garden is very useful, it is important to note that the session information for each worker process is unique. Because requests are routed to the application pool worker process in a round-robin fashion, Web gardens may have little effect on applications where session information is stored in the process. In a few cases, having multiple worker processes running the same application can cause resource competition. For example, if all worker processes attempt to log information to a log file, or use resources that are not specific to multiple concurrent accesses, resource race issues can arise.

If these problems don't exist, then Web Park may be one of the features you need, and it can be very useful.