[Feature]: MetaNode support rocksdb store mode

[NaturalSelect]

Contact Details

huangzhibin1@oppo.com

Is there an existing issue for this?

• I have searched all the existing issues

Is your feature request related to a problem? Please describe.

Rocksdb is a popular key-value database, and has been widely used in many fields.

Supports rocksdb storage mode, so we can place metadata on disk and reduce the cost of the metadata subsystem.

Describe the solution you'd like.

• Each disk own a rocksdb instance, so we can share block cahce and write buffer. Using prefix key to isolate different meta partitions.
• Support migrate a memory meta partition(replica) to rocksdb meta partition.
• Refactor behavior of extent deletion, use a new kind of tree to store deleted extent data.
• Monitor available space of each disk and report it to master, adjust our node and nodeset selector to support disk space based meta partition placement.
• Support configurate default meta partition store mode of volume.

Describe an alternate solution.

No response

Anything else? (Additional Context)

No response

[leonrayang]

be include in 2024 roadmap