What is HTTP. sys?

Introduction to HTTP. sys

HTTP. sys

Is an operating system in win2003 and WINXP SP2Core ComponentsAllows any application to communicate with each other over HTTP through the interfaces provided by the application.

Tip: If you accidentally delete the driver file, you don't have to worry about it. The driver will be rebuilt the next time the system starts. Is a core component of the system that cannot be deleted! PracticalProgramAfter the driver is terminated, the driver will be re-created immediately (only the files to be crushed cannot be re-created immediately, but after the driver is crushed, it will be re-created next time ).

Microsoft introduced a new http api and Kernel Mode Driver HTTP. sys in Windows 2003 Server to make HTTP service-based programs more efficient. The direct beneficiaries of this change are IIS 6.0 and ASP. NET.

In fact, after Windows XP installs SP2, HTTP. sys has already appeared in the system, but in fact, the operating system does not actually use this kernel-level driver, and IIS 5.1 on XP does not use HTTP APIs.

The core changes in the new http api are encapsulated in the kernel mode driver of HTTP. sys. Previously, HTTP-based programs run in user mode, and must handle software interruptions, context switches, thread scheduling, and other issues by themselves, and are often unable to freely access system resources. In the past, HTTP servers, such as IIS and Apache, used Winsock APIs to create a network listener in user mode. The Network listener (I. e.: per application or per Thread basis) occupies an IP port. In layman's terms, only one application can listen to one port at a time, which is sometimes an uncomfortable restriction.

Benefits of HTTP. sys

The new HTTP. sys offers the following benefits:

1. cache-static content is now cached in kernel mode, which enablesFaster service response

2. Log-IIS's log function is faster and standardized

3. bandwidth control-greater scalability control and throttling

4. reliability-all service requests are sent over HTTP. in sys, it is saved into the queue rather than processed by the service program itself. In this way, even if the service program is restarted, the unprocessed requests will not be lost.

5. IP port reuse-now, as long as it is through HTTP. the ports managed by sys (including the famous ports such as 80) can be monitored by multiple programs at the same time.