Performance Implications of Windows SharePoint Services 2.0 Features

Server performance can be affected by many variables; some are predictable, others are not. For example, you can't always anticipate periods of heavy demand on a week to week basis, but you can usually predict daily periods of heavy or light use. One way to gain better control of your server's performance is to minimize the performance impact of Microsoft Windows SharePoint Services features on your server.

As with any software, some features of Windows SharePoint Services take up more resources than others. For example, features that rely on the Microsoft SharePoint Timer service, such as alerts and usage analysis log processing, can have more of an impact on your server performance than other features. This is because features that use the SharePoint Timer service are run during specific time ranges, and most of these features sort through many files on each site. By default, the time ranges for SharePoint Timer service jobs are staggered, and set to times when Web site usage is typically low. Features that use the SharePoint Timer service tend to have cyclical performance impact. When the SharePoint Timer service starts the task, server performance is affected, but after the task has been completed, performance returns to normal. Other features can affect server resources for different reasons, but usually performance is impacted when a feature must be run on demand when a user performs a particular action.

By configuring appropriate settings for features, or choosing to disable them, you can control the impact they have on performance. The following features, because of their reliance on system processes, have a greater impact on performance than other features in Windows SharePoint Services:

• Antivirus protection

  When you enable antivirus protection, each file on the server that is uploaded or downloaded is scanned for viruses and potentially cleaned if a virus is found. This process inherently impacts the download and upload time for files. You can minimize the performance impact by setting a quicker time out for scanning and by allocating more or fewer threads to the process. For more information about changing antivirus settings, see Configuring Antivirus Protection (Windows SharePoint Services 2.0).

• HTML viewing

  The HTML viewing service converts files and documents into viewable HTML format. Because this viewing happens on demand, it can take up a lot of resources. It is recommended that you always use a separate server to host the HTML viewing service so that the viewing service performance does not impact the performance of your Web server. For more information about changing HTML Viewer settings, see Managing HTML Viewers (Windows SharePoint Services 2.0).

• Usage analysis logging and processing

  Usage analysis logging has a fairly low impact on server performance — less than 10%. However, usage log processing runs separately from the main Windows SharePoint Services process, and is a resource-intensive task. Log processing relies on the SharePoint Timer service, so one thing you can do to minimize the performance impact is to schedule log processing for times when you know use of your sites is low. You can also increase the number of log files to improve logging performance, or decrease the number of log files to improve log file processing performance. For more information about changing usage analysis settings, see Configuring Usage Analysis (Windows SharePoint Services 2.0).

• Site use confirmation and auto-deletion

  This feature helps you monitor and delete Web sites that are not being used. It also relies on the SharePoint Timer service to check for unused sites, to send e-mail alerts about unused sites to site administrators, and to automatically delete sites. As with any other feature that uses the SharePoint Timer service, you can configure the process to run at an appropriate time when your server is less heavily used. Also, because this feature is controlled at the virtual server level, you can stagger the times for each virtual server, so that not all virtual servers are being checked for unused sites at the same time. For more information about changing settings for site use confirmation, see Managing Unused Web Sites (Windows SharePoint Services 2.0).

• Alerts

  Daily and weekly alerts do not impact performance heavily, but if you have a large number of immediate alerts being sent, it can slow your server down. This feature also relies on the SharePoint Timer service, so you can specify the times for daily and weekly alerts, and you can set a longer interval for immediate alerts (the default is every 5 minutes, but you may want to extend it to 15 minutes, for example). You can also limit the number of alerts each user can sign up for, so that your server is not flooded with alert requests. Also, because alerts are controlled at the virtual server level, you can stagger the time ranges for each virtual server, so that not all virtual servers are sending alerts at the same time. Keep in mind that the only way to determine the amount of server resources being taken up by sending alerts is to monitor your SMTP server for a lot of outbound traffic. For more information about changing alert settings, see Managing Alerts (Windows SharePoint Services 2.0).