[FLINK-10040] Decompose RocksDBKeyedStateBackend

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Resolved
• Component/s: Runtime / State Backends
• Labels: auto-deprioritized-major auto-unassigned
• Assignee: Unassigned
• Reporter: Stefan Richter
• Created: 03/Aug/18 08:13
• Updated: 08/Dec/21 09:18
• Resolved: 08/Dec/21 09:18

Description

Over time, the class RocksDBKeyedStateBackend has grown to around 3000 LOC, with a lot of inner classes (different checkpoint/restore strategies, iterators, etc).

I suggest to decompose it and improve how dependencies to the classes are provided in construction, so that things become better to maintain, extend, and test.

Will break down this work into multiple tasks, ordered by estimated difficulty/time required.

Sub-Tasks

• Extract all different iterators (inner or static inner classes) into full classes: Closed
• Extract snapshot algorithms from inner classes into full classes: Closed
• Refactor object construction/inititlization/restore code: Closed
• Check proper RIA style and introduce it where missing: Closed
• Use ByteArrayDataInput/OutputView instead of stream + wrapper: Closed