Located in the folder: /var/log/dpi/fastdpi_alert.log
The fastdpi_alert.log file contains information about errors and informational events. The first field = message class. Followed by diagnostic information and the text of the informational message, applied DPI platform parameters (during restart or hot parameter updates), or error messages.

[WARNING ][2021/06/01-14:52:45:237379][0x7f11cc0f2c00] [HAL][DPDK] run_device_port: Cluster #0, device '03:00.0' port_id=0: link status DOWN
...
[COMMON  ][2021/06/01-14:46:38:634458][0x7f4d0f486c00] Start with sched options : policy=SCHED_OTHER(0), prio=0, prio threads :
		main    : 0
		bllist  : 0
		ctrl    : 0
		netflow : 0
		bmp     : 0
		ajb     : 0
...
[ERROR   ][2021/06/01-14:49:55:367480][0x7f3c6cfe7400] [PCRF-CLI] ajb:connect_to: connect() to 127.0.0.1%lo:29002 error: errno=111, 'Connection refused'

Information about successful blacklist updates from the cloud service:

[INFO    ] bl_updater_thread : URL black list download with result, rc=1001 : Success.
[INFO    ] bl_updater_thread : IP black list download with result, rc=1001 : Success.