Log entries would be generated in two situations: at session initialization and at session close. At session initialization, the log entry would include details about the connection, such as the source and destination IP addresses, the service being used, and the action taken by the security policy. At session close, the log entry would include details about the connection, such as the duration of the session, the bytes sent/received, and the action taken by the security policy. For more information, you can refer to the Juniper Security documentation at https://www.juniper.net/documentation/en_US/junos/topics/reference/configuration-statement/security-log-configuration.html.