Server Responsiveness Degrades and Queries Time Out When You Run the DNS Server Service

When you run the DNS Server service under Microsoft Windows Server 2003, after a short time of operation, within 60 minutes or less, you may notice a degradation in server responsiveness, and queries may start to time out.

Hotfix Information

A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site: Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.

Prerequisites

No prerequisites are required.

Restart Requirement

You must restart your computer after you apply this hotfix.

Hotfix Replacement Information

This hotfix does not replace any other hotfixes.

File Information

The English version of this hotfix has the file attributes (or later) that are listed in the following table. The dates and times for these files are listed in coordinated universal time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.

There is no suggested workaround. To minimize the effects of the problem, periodically stop and then restart the DNS Server service.

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section of this article.

As soon as Windows Server 2003 starts servicing client DNS queries, the CPU utilization for the DNS process will start increasing in a linear fashion. At some point, typically within an hour, the CPU utilization for the DNS process may hit 100 percent on each CPU, depending on the relative performance of the hardware.

As the CPU utilization increases toward 100 percent, you may also notice a leak in Private Bytes for the DNS process.

If the load level is sufficiently high and if it is sustained for a sufficient length of time, there will be a noticeable degradation in the DNS server's responsiveness.

As the system degrades in responsiveness, queries will start to time out. If you use the NSLOOKUP tool with a higher-than-normal timeout setting (for example, 20 seconds instead of 2 seconds), you will notice that most queries are in fact still being serviced. However, it takes a long time for the DNS server to respond.