hi all,

seek your help for this.

we are using luminous 12.2.12 and we enabled 3 active mds.

when I running “ceph daemon mds.<x> dump loads” on any active mds, I always saw such like below

    "mds_load": {

        "mds.0": {

            "request_rate": 526.045993,

            "cache_hit_rate": 0.000000,

…

        "mds.1": {

            "request_rate": 169.845956,

            "cache_hit_rate": 0.000000,

…

        "mds.2": {

            "request_rate": 300.511478,

            "cache_hit_rate": 0.000000,

don’t understand what’s this ‘cache_hit_rate’ and why it seems always 0?

we actually set a bigger mds_cache_memory_limit than default such like 16G in /etc/ceph/ceph.conf. are they related?

I checked https://docs.ceph.com/docs/luminous/cephfs/mds-config-ref/ , but didn’t get further clue from the description of “mds cache *” settings.