Tempo - Enable cache settings

Hi We are using Tempo version - 2.1.1
We have enabled cache: settings in values.yaml file and we also added some properties as shown in screen shot below.
For some reason i dont see any activity going on in memcached container .
I dont see logs , neither i see any significant usage of CPU or RAM .
Are we supposed to see the logs of cache in memcached pods , or is there another location to it ?
Any inputs would be very helpful to understand .

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