[IGNITE-11739] Refactoring of cache lifecycle and cache configuration management code

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: cache
• Assignee: Unassigned
• Reporter: Sergey Chugunov
• Created: 12/Apr/19 16:06
• Updated: 12/Apr/19 16:43

Description

Problem

Currently code responsible for cache lifecycle and configuration management is spread across different entities (e.g. GridCacheProcessor, GridCacheAffinityManager, ClusterCachesInfo and so on).
Cache configuration data is duplicated multiple times and presented in different forms from StoredCacheData to CacheGroupDescriptor to DynamicCacheDescriptor to ClusterCachesInfo.

Altogether there is no entity nor abstraction which contains most of the logic of managing cache state and config and provides a clean API for this purpose.

All this makes it hard to maintain the code, fix bugs and make improvements so need for refactoring and benefits from it are obvious.

Approaches

1. Build state machine manipulating immutable state objects to reflect transitions between states.
2. Concentrate all cache-related info into a new (abstraction like cache container) or existing (e.g. cache context) mutable entity and manipulate that entity to reflect evolution of cache.
3. Some mix of these two approaches.

There are already plenty of entities like CacheInfo or CacheDescriptor with names suggesting they contain information about cache.
The problem though is that each of these entities manages only some part of information.

Regardless of which approach is used clear and well documented API should be provided for managing lifecycle and configuration.