Guidelines for Troubleshooting Search Issues


Topic Last Modified: 2005-05-12

When you troubleshoot search issues, use a test topology and make sure to note what the typical behavior of your system should be (server performance and transaction log generation behavior). Also, have detailed information about what type of searches are involved and how they are processed, especially if the searches are created using a custom application.

If you have a folder that is searched frequently (without reusing existing search requests), you may see the following behavior on the server where the folder resides:

  • The amount of free disk space drops noticeably as Exchange Server 2003 generates excessive transaction logs.

  • Excessive server load slows down operations such as opening folder items or expanding the folder tree. If Exchange Server 2003 is frequently creating and updating search folders, the load on the server may increase to the point that Exchange Server 2003 appears to be unresponsive.

If either problem becomes extreme, the Microsoft Exchange Information Store service (MSExchangeIS) may stop responding.

Sometimes, you may be able to quickly alleviate the issues described earlier in this section. However, these methods probably will not solve the original cause of the problem. They are only intended to keep your system functioning while you find a true resolution. For more information about permanently resolving issues, see "Resolving Issues" later in this topic.

If transaction logs are taking up too much disk space, reduce them by performing a full online backup of the Exchange Server 2003 databases. The backup operation cleans up log files that are no longer necessary.

Never try to remove transaction log files by deleting them. If your databases fail, you may not be able to recover them without a complete set of transaction logs. When the backup operation truncates the log files, it first makes sure that all appropriate data has been correctly committed to the database. Transactions that are not fully completed are left in the log files.

If Exchange Server 2003 appears to be unresponsive (processing has stopped or is very slow), restarting services can alleviate the symptoms:

  • If the MSExchangeIS service has stopped, restarting it will probably restore typical performance. However, before restarting the service, make sure that Exchange Server 2003 has not run out of disk space. The service will not start if free disk space is not sufficient.

  • If your system supports many HTTP/DAV search requests, try restarting the World Wide Web Publishing Service and canceling all pending requests.

In any case, performance problems are likely to happen again unless you eliminate the actual cause of the problem.

If you are having problems as a result of too many search folders, you can delete existing search folders by using the Reset Views registry key. The effect of this registry key is temporary. During the store's maintenance cycle, Exchange Server 2003 cleans up the existing search folders, and then resets the registry key to its normal value. Afterwards, Exchange Server 2003 resumes creating search folders normally. Meanwhile, you should take action to reduce the number of search folders needed.

For detailed steps about how to resolve problems that result from having too many search folders, see How to Temporarily Reset Cached Views.

You can use the following techniques to isolate and resolve search-related issues:

  • Using the guidelines presented earlier, streamline search requests as much as possible.

  • If you have changed the default values for the maximum number of search folders or the search folder retention period, re-evaluate the values you are using to make sure they are not the cause of the problem.

  • Check how users or applications in your system typically post, reference, update, and delete folder items. Remember that changing an unread item to a read item counts as an update.

  • Check folder permissions. To search a folder, users or custom applications must have the appropriate permissions to access the folder. If the users or custom applications do not have at least Read permissions to the folders they are searching, their searches will not return the expected results.

  • Identify the processes that access the folders and check the performance of each. You can use Performance Monitor and a test environment to isolate processes that have unusually high loads.

  • Use diagnostic logs such as Internet Information Services (IIS) logs to identify the most frequently used search requests.