tailieunhanh - microsoft press internet information services iis 70 resource kit phần 9

Bảng 17-4 bộ nhớ đếm Đo Quy trình tên truy cập (w3wp) \ Virtual Bytes Mô tả Kích thước hiện tại, theo byte, của không gian địa chỉ ảo quá trình sử dụng. Sử dụng không gian địa chỉ ảo không nhất thiết phải bao hàm sự sử dụng tương ứng của một trong hai ổ đĩa hoặc các trang bộ nhớ chính. Ảo không gian là hữu hạn, và quá trình có thể hạn chế khả năng của nó để tải các thư viện. | 620 Part IV Troubleshooting and Performance Table 17-4 Memory Counters to Measure Counter Name Description Process w3wp Virtual Bytes The current size in bytes of the virtual address space the process is using. Use of virtual address space does not necessarily imply corresponding use of either disk or main memory pages. Virtual space is finite and the process can limit its ability to load libraries. Process w3wp Working Set The current size in bytes of the Working Set of this process. The Working Set is the set of memory pages touched recently by the threads in the process. If free memory in the computer is above a threshold pages are left in the Working Set of a process even if they are not in use. When free memory falls below a threshold pages are trimmed from Working Sets. If they are needed they will then be soft-faulted back into the Working Set before leaving main memory. Impact of Constraints When a server is low on RAM it uses the paging file causing the worker process to have to retrieve data from disk slowing down performance. This can be an expensive operation because the application has introduced another potential bottleneck Disk I O Input Output . An application that is forced to use a portion of the information swapped to the paging file has added latency and causes the server to use more resources. Generally with 32-bit operating systems the recommended approach is to set the paging file size to be times the amount of RAM. In a 64-bit environment you can set the operating system to automatically handle the paging file size. Countermeasures One countermeasure against memory pressure is to verify that your Web server paging file is configured properly and optimized on a separate set of disks. Spreading a paging file across separate physical disks enables you to improve paging file performance by using drives that do not contain your site s content or log files. Although these steps are basic they can go a long way toward helping your application s