Hey Vadim, According to https://druid.apache.org/docs/latest/operations/metrics.html#cache, today, the number of hits and misses for the hybrid cache are both emitted, but there isn't differentiation between L1 hits and L2 hits. Is that what you mean?
If so, I think the main issue is there just isn't any place for them in the metric schema described in the doc page above. There's just one set of standardized "query/cache/delta/" and "query/cache/total/" metrics, without specifying how things would be broken down if you had a multi-level cache. If you proposed an update to the schema that maintains compatibility with the existing one (this'll probably mean emitting some new metrics), I think that'd be a good start. Then you could implement it and have it incorporated into Druid via pull request. On Wed, Feb 24, 2021 at 12:37 AM Vararu, Vadim <vadim.var...@adswizz.com> wrote: > Hi all, > > I’ve found out that the L1 cache hits/misses metrics are not emitted. Only > the total number of requests (hits+misses). Any reason for that? Where > could I suggest that to be implemented? It seems essential when it comes to > caching and I see no technical challenge with that. > > Thanks, > Vadim. >