Rotating a log file refers to closing a log file being used by a running data server or display server and opening a new log file to be used instead from that point onwards. This lets you archive log files and avoid log files that are too large to easily view.

Each site should decide on and implement its own log rotation policy. You should consider the following:

There is a lot of useful header information in the log file being used when the data server or display server starts. If you need to provide log files to Apama technical support, you should be able to provide the log file that was in use when the data server or display server started, as well as any other log files that were in use before and when a problem occurred.

Logging for data servers and display servers is configured using standard Log4j configuration files. You can find them in the etc directory of your Apama installation:

By default, the above files configure the servers to rotate the log files when they reach a certain file size. If you want to enable time-based rotation instead (for example, to rotate the log files on a monthly basis), see the Log4j 2 documentation at https://logging.apache.org/log4j/2.x/.

There are many external resources which can be found online regarding how to configure Log4j for different purposes. In the case of more advanced configurations, you may consider consulting these.