Ntopng configuration and data loss when shutting down Redis
In addition to monitoring information, ntopng stores configuration/customization performed using the ntopng GUI in the Redis database.
The default Redis configuration flushes writes to disk every 15 minutes. When shutting down, ntopng.sh sends a SIGTERM to the Redis server, which causes in the Redis server exiting immediately without flushing pending writes to disk. This results in the loss of all data and configuration written since the last sync to disk.