By default, the Personalization module sends all logging data into flat files to optimize performance for large sites. Depending on the load of a Web site, you may or may not want to store all logging data directly in a database. Typically, large sites perform nightly bulk copy operations from the flat file logs into databases if they want their data available for querying. The Personalization module’s log file names are time-stamped down to the millisecond, to make them more or less unique on server restarts.

All aspects of the file names for the logs can be configured. This is especially useful if you want to uniquely identify each log file per ATG server. In addition, you can set a file sink’s schedule property to automatically flush and close files currently being used and rotate to a new log file. By default, this schedule is set in the logFileRotationSchedule property of /atg/reporting/Configuration to perform this operation at 1 AM every night. See the Logging and Data Collection chapter in the ATG Platform Programming Guide for more information about formatting and scheduling logs.