NOTE
Netty ByteBufAllocator
Allocator abstraction for heap/direct, pooled/unpooled buffers and why allocation strategy is configurable.
This is a historical learning note and may contain outdated or incomplete understanding.
ByteBufAllocator centralizes allocation of byte buffers so handlers do not hard-code one storage strategy. Allocators can return heap or direct buffers and can use pooling.
This abstraction allows transport/framework configuration to choose allocation behavior while application codecs request buffers by capacity/usage intent.
Direct and pooled buffers can improve high-throughput workloads but add native-memory/reference-counting complexity. Measure memory/CPU/latency and respect ownership rather than assuming one allocator is always best.