In an application, the file rollover process closes the current file and creates a new file on the basis of file size or time.
When you write to a file target, you can perform the following types of rollover:
- Size-based rollover
- You can configure a target service to perform target file rollover when it reaches a certain size. To configure size-based rollover, specify the
Rollover Size and
Date and Time Format properties of the target service.
For example, set the rollover size as 1 MB, name of the file target as
target.log, and a date and time format of your choice. If the source service sends 5 MB to the file target, the file target first creates the
target.log.<timestamp> file. When the size of
target.log.<timestamp> reaches 1 MB, the target service rolls the file over.
- Time-based rollover
- You can configure a target service to perform target file rollover when a certain period of time has elapsed. To configure time-based rollover, specify the
Rollover Time property of the target service.
You can implement both size-based rollover and time-based rollover for a target file, in which case the event that occurs first triggers a rollover. For example, if you set rollover time as 1 hour and rollover size as 1 GB, the target service rolls the file over when the file reaches a size of 1 GB even if the 1-hour period has not elapsed.
The target file to which the target service is writing data is the active file. Files that the target service closes after performing a rollover are archived files.