The Redis info command contains keyspace_hits and keyspace_misses in its various statistics. keyspace_misses will increment every time you ask to read from a key Redis doesn't have.
If you need more granular information I suggest modifying your cache fetch logic to write missing keys to a Redis sorted set or list so you can see which keys are going missing. You'll have to also come up with a way of purging this data periodically so it doesn't grow out of control, unless your total keyspace is pretty limited.
Answer from Carl Zulauf on Stack Overflowmonitoring - Obtaining keyspace hit and miss from Redis - Stack Overflow
Redis Cache keyspace miss issue
[redis 8.0.1]why are keyspace_hits and keyspace_misses always 0 on a replica?
Moodle in English: Redis keyspace misses | Moodle.org
The Redis info command contains keyspace_hits and keyspace_misses in its various statistics. keyspace_misses will increment every time you ask to read from a key Redis doesn't have.
If you need more granular information I suggest modifying your cache fetch logic to write missing keys to a Redis sorted set or list so you can see which keys are going missing. You'll have to also come up with a way of purging this data periodically so it doesn't grow out of control, unless your total keyspace is pretty limited.
It's become possible starting with Redis 6.0. New key 'm' added:
m Key miss events (events generated when a key that doesn't exist is accessed)
For example, you can see missed keys in console with 'redis-cli':
user@redis-server:~# redis-cli config set notify-keyspace-events Km
OK
user@redis-server:~# redis-cli --csv psubscribe '__key*__:*'
Reading messages... (press Ctrl-C to quit)
"psubscribe","__key*__:*",1
"pmessage","__key*__:*","__keyevent@0__:keymiss","<< actual data >>"
......
source: https://redis.io/topics/notifications
You can get these stats programmatically through the normal Redis interface:
> INFO
...
keyspace_hits:414197256
keyspace_misses:661663278
...
See the INFO command documentation for more.
Redis doesn't speak HTTP; it only speaks the Redis protocol. You could put webdis in front if required.
You can usually get all the info you need from just connecting to the server with any redis client.
You can get all the info by using this command Info.
There is an interesting article here that the Author shows how to trace gets and sets and messing around with the redis source code.
There is some third party tools that lets you monitor redis a quick google search you give you a few like this one. (I am not endorsing them it is just an example).
There is also the monitor command in redis that shows you everything as it happens which you could make your own monitoring app.