Monitoring and Tuning Your Server

Suggestions for Optimizing Memory Usage

Servers running IIS 5.0, like other high-performance file servers, benefit from ample physical memory. Generally, the more memory you add, the more the servers use and the better they perform. IIS 5.0 requires a minimum of 64 MB of memory; at least 128 MB is recommended. If you are running memory-intensive applications, your server could require a much larger amount of memory to run optimally (for example, most of the servers that service the microsoft.com Web site have at least 512 MB of memory).

Adding RAM to your system is not the only option, however. Here are a few suggestions for optimizing memory performance without adding memory:

Improve Data Organization Keep related Web files on the same logical partitions of a disk. Keeping files together improves the performance of the File System Cache. Also, defragment your disks. Even well-organized files take more time to retrieve if they are fragmented.
Try Disk Mirroring or Striping The optimum configuration is to have enough physical memory to hold all static Web pages. However, if pages must be retrieved from disk, use mirroring or striping to make reading from disk sets faster. In some cases, a caching disk controller may help.
Replace or Convert CGI Applications CGI applications use much more processor time and memory space than equivalent ASP or ISAPI applications. For more information about ASP, ISAPI, and CGI applications, see Web Applications.
Enlarge Paging Files Add paging files and increase the size of the ones you have. The Windows 2000 operating system creates one paging file on the system disk, but you can also create a new paging file on each logical partition of each disk.
Retime the IIS Object Cache Consider lengthening the period that an unused object can remain in the cache (use the ObjectCacheTTL setting in the registry, as mentioned earlier in this section, to accomplish this).
Caution Do not use a registry editor to edit the registry directly unless you have no alternative. The registry editors bypass the standard safeguards provided by administrative tools. These safeguards prevent you from entering conflicting settings or settings that are likely to degrade performance or damage your system. Editing the registry directly can have serious, unexpected consequences that can prevent the system from starting and require that you reinstall Windows 2000. To configure or customize Windows 2000, use the programs in Control Panel or Microsoft Management Console (MMC) whenever possible.
Change the Balance of the File System Cache to the IIS 5.0 Working Set By default, servers running the Windows 2000 operating system are configured to give preference to the File System Cache over the working sets of processes when allocating memory space. Although IIS 5.0–based servers benefit from a large File System Cache, the setting Maximize Throughput for File Sharing often causes the IIS 5.0 pageable code to be written to disk, which results in lengthy processing delays. To avoid these processing delays, set Server properties to the Maximize data throughput for network applications option.
To change Server properties
1. On the desktop, open My Computer and select Network and Dial-up Connections.
2. Right-click Local Area Connection and open its property sheet.
3. Select File and Printer Sharing for Microsoft Networks and select Properties.
4. On the Server Optimization property sheet, select Maximize data throughput for network applications.
Limit Connections If your server doesn’t have enough memory, limiting the number of connections on the server might help alleviate the shortage because some physical memory (about 10 KB per connection) is consumed by the data structures the system uses to keep track of connections.
To control the number of current connections
1. In the IIS snap-in, right-click a site, then choose Properties and select the Web Site tab.
2. Select the Limited To check box in the Connections panel. Type into the field the maximum number of connections you want to allow.
Eliminate Unnecessary Features You can also disable the performance boost for applications in the foreground. In addition, at times when you are not actively checking performance, you can disable performance-related logging in order to squeeze a bit more performance from your server.