[improve] PIP-384: ManagedLedger interface decoupling

[lhotari]

Rendered PIP document PIP-384: ManagedLedger interface decoupling

Motivation

Apache Pulsar uses a component called ManagedLedger to handle persistent storage of messages.

The ManagedLedger interfaces and implementation were initially tightly coupled, making it difficult to introduce alternative implementations or improve the architecture.
This PIP documents changes that have been made in the master branch for Pulsar 4.0. Pull Requests #22891 and #23311 have already been merged.
This work happened after lazy consensus on the dev mailing list based on the discussion thread "Preparing for Pulsar 4.0: cleaning up the Managed Ledger interfaces".
There is one remaining PR #23313 at the time of writing this document.
The goal of this PIP is to document the changes in this area for later reference.

Documentation

• doc
• doc-required
• doc-not-needed
• doc-complete