This PR is mainly do three things: 1. Fix fe meta version bug introduced by #4029 , when fix conflict with #4086 2. Make drop check code easy to read 3. Add doc content for drop meta check
# fe-common This module is used to store some common classes of other modules. # spark-dpp This module is Spark DPP program, used for Spark Load function. Depends: fe-common # fe-core This module is the main process module of FE. Depends: fe-common, spark-dpp