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How Webtrends Analytics uses the high water mark for analysis

Products

Webtrends Analytics 8.x
Webtrends Analytics 9.x

Cause

Webtrends Analytics uses what is referred to as the high water mark with in the FastTrends (report) database to determine when to start reading logs from(date/time stamp).

When an analysis process starts it scans the log files for all hits after the current high water mark. As the hits are read in from the logs, the high water mark gets moved forward, repeating this process until the last second of a log file has been reached. It does not process the last second of the log file until it moves on to the next log file. When reading the log file the high water mark would be moved to the last second of the log file any others with the same date/time stamp would not be processed until it reads the next log file.

The high water mark can only be restored to a prior date/time stamp by restoring a Webtrends backup. This will set it to the date/time stamp when the backup was performed and then the profile can be analyzed to process the logs from that time forward.