[Metric] Add partition and bucket count per table

[zcoo]

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Motivation

When a Fluss cluster is used in production, it's hard to locate which table occupies most count of bucket and partition. Sometimes a table with unsuitable schema can make whole cluster unhealthy. e.g. a table with

'bucket.num' = '2048',
'table.auto-partition.num-retention' = '180'

totally make 2048*180=368640 buckets and 3 times replicas, which ruin the cluster.
Thus it's necessary to monitor the partition count and bucket count per table and per database. Currently we only have metrics of bucket count and partition count per cluster.

Future, we may limit the above parameter to protect the cluster, but first, in this issue I just want to monitor it.

Solution

support metrics bucket count and partition count per table and per database
No response

Anything else?

No response

Willingness to contribute

• I'm willing to submit a PR!