Shared cluster local metadata cache for cloud juicefs

[vicaya]

I'd prefer using cloud juicefs for my local clusters as well for ease of maintenance. But the perf is not so great due to high network latency (10+x compared with local) to cloud servers. The problem is especially acute for large amount of cluster local (for both producers and consumers) intermediate data, where cluster local cache would help a lot. The cluster data perf could be addressed partially by minio tiering. It'd be great if you can support a cluster local (redis or generic) metadata cache that is incrementally sync'ed (e.g. every 1-10s) to the cloud metadata store. IMO, this would greatly improve the usability of cloud juicefs for on-prem/edge clusters. With a lease based consistent cache implementation, we can also have a pretty performant global juicefs as well.

Wonder if you any plans to address the issue.