Mridul M

Sounds good @kevin85421, wanted to make sure the approach is extensible to others. Can you please file follow up jira's for both ? Thx

I am fine with the changes, will let @Ngone51 take a look/merge

I have not looked at the PR in detail, but we have to be careful to preserve backwards compatible and not make breaking changes.

+CC @shardulm94, @thejdeep

I will let @Ngone51 review/merge - I do not have a lot of context on standalone :-)

This is a recent change, to add missing functionality for preserving merge data across restarts. Please tag me when you have an updated PR @LuciferYang, will help review it.

> @dongjoon-hyun @mridulm Conflict is resolved and GA passed. But I think we should make sure that [SPARK-38888](https://issues.apache.org/jira/browse/SPARK-38888) is worth to do before reviewing, because this pr is the pre-work...

@dongjoon-hyun > Actually, instead of providing wrapper layer, the final goal is the removal of LevelDB in favor of RocksDB. I am sure in future, we might have another SPIP...

nit: Btw, from a completeness point of view, DB.get makes sense to include :-)

Merged to master. Thanks for working on this @LuciferYang ! Thanks for reviews @dongjoon-hyun, @zhouyejoe and @tgravescs :-)