This section describes the performance impact of some portal site background operations.

Recommendation

Schedule asynchronous operation tasks during off-peak hours to minimize the performance impact on the solution.

Audiences

The performance impact of audience calculation on portal site performance is typically less than 10 percent. In the test labs, the throughput impact of audience calculation on a medium farm measured 110 pages per second for a home page access without audience calculation, and 106 pages per second with audience calculation turned on.

Audience calculation is a disk-intensive operation and, therefore, may compete with other disk-intensive operations such as indexing.

Backup

Usually, SharePoint Portal Server 2003 backup performance is approximately 4 to 6 MB per second. Backup is a disk I/O-bound operation and performance depends on the location of the backup media (local disk or network share).

So, for example, if the portal site contains 1 GB of content, the expected restore time is:

The backup process effect on the portal site throughput is typically 5 percent.

Indexing

The overall performance of the indexer depends on the following four areas: propagation, merging, indexing and alerts.

The indexing process is affected not just by the number of documents indexed and their location, but also by the number of alerts present on the content that is indexed.

Having more than four indexes on each indexer in a farm configuration is not recommended. This is partly because cross-index queries are slower and have less accurate relevance, and also because of the performance impact of the propagation and merging of indexes to the search server. However, keeping content with stringent freshness requirements on a separate content index allows it to be propagated more quickly.

After the index management server updates the content index file, it is copied to the search server and merged with the other content index files.

The performance of the indexes degrades when the number of documents in the index exceeds 5 million documents.

The indexing process uses a high number of database connections; therefore, using MSDE for a solution with a large number of documents is not recommended, because MSDE provides for a maximum of five concurrent jobs.

In the test labs, the performance of the crawl is approximately 33 documents per second on a dual processor index management server. When 100,000 subscriptions were added to a document mass of 2,500,000, the degradation of the indexer performance was approximately 17 percent.

Recommendations

• Have no more than four indexes on each indexer in a farm configuration.
• Keep content with stringent freshness requirements on a separate content index.
• Limit documents in an index to 5 million.
• Limit alerts on a portal site solution to 1 million.
• Do not use MSDE for a solution that contains a large number of documents.

Index Propagation

The amount of time required to propagate an index to the search server can vary depending on the number of documents included in the index and the amount of metadata in the index. Typically, the performance of index propagation is approximately 2.5 MB per second.

Profile Import

The profile import process reads data from the Active Directory directory service to populate user information into the SharePoint Portal Server databases. This is a pure read-only operation that does not modify the Active Directory in any way. On a medium farm, the expected performance of the profile importer is approximately 30 profiles per second.

Restore

Usually, the performance of the SharePoint Portal Server 2003 restore is approximately 4 MB per second. Restore is a disk I/O-bound operation and performance depends on the location of the media (local disk or network share) from which the restore is performed, and whether the restore is done to a local or remote SQL Server.

So, for example, if the portal site contains 1 GB of content, the expected restore time is:

1,000 MB / 4 MBps = 250 s.

250 seconds is about 4 minutes.