What is better to use to store unique ip addresses per day?

Question

PHP

I would like to get advice on what is the most relevant method of storing and retrieving unique data per day.
A little about the load and data:
IP addresses come to the php script via udp every minute about 2 thousand times (80 percent are all repetitions), it is necessary to record only unique values ​​​​for today in the database in the future. That is, there are 3 fields id (autogenerated), ip, datatime. the script is launched and a constant exchange of packets begins.
As I see it, it is necessary to install either redis or memcache and enter all absolutely addresses into the RAM cache, after which, for example, every 5-10 minutes, enter only unique ip, datatime entries for today.

Answer 1

Redis is quite up to the task.
For example, for each ip, generate a key of the form дата:ip. For example SET "20210205:192.168.1.5" "", for each ip, create a key with an empty string.
After midnight, IPs will be saved with a new date, and the PHP cron script will parse the previous day KEYS "20210205:*"and save the collected IPs to the database.
It is even better to keep every day as a hash, where the name is the date, the ip fields, and the hit counter values ​​from this ip. Do it every time HINCRBY "дата" "ip" 1 See HINCRBY
PS ip, if there is only IPv4, it's 4 bytes, can be stored as integers, not strings - more compact.