defmodule Nebulex.Distributed do @moduledoc """ Distributed caching adapters for [Nebulex](https://hexdocs.pm/nebulex). This package provides adapters for building distributed cache topologies on top of Nebulex. Each adapter wraps a local cache adapter (e.g., `Nebulex.Adapters.Local`) and adds a distributed layer on top of it. ## Adapters * `Nebulex.Adapters.Partitioned` - Partitioned cache topology where data is sharded across cluster nodes using consistent hashing. Each node owns a subset of the keyspace, providing linear scalability and single-hop point-to-point operations. * `Nebulex.Adapters.Multilevel` - Multi-level (near) cache topology with a hierarchy of cache layers (e.g., L1 local + L2 distributed). Reads check levels in order for fast local hits with fallback to slower shared layers. Writes use a write-through policy. * `Nebulex.Adapters.Coherent` - Local cache with distributed invalidation via `Nebulex.Streams`. Each node maintains its own independent local cache for maximum read performance; entries are only present on nodes that have fetched them. Writes broadcast invalidation events across the cluster so other nodes delete stale entries and fetch fresh data on the next read. * 🚧 `Nebulex.Adapters.Replicated` - Replicated cache topology where every node holds an identical copy of the entire cache. Writes are broadcast to all nodes so data is immediately available locally on every member of the cluster. **Planned for a future release.** ## Choosing an Adapter | Aspect | Partitioned | Multilevel | Coherent | |---------------------|----------------------|-----------------------|------------------------| | Data location | Sharded across nodes | L1 local + L2 shared | Independent per node | | Read performance | Network hop required | L1 fast, L2 slower | Fastest (pure local) | | Write behavior | Remote write to owner| Write through levels | Local + invalidation | | Consistency | Strong (single owner)| Varies by config | Eventual | | Network overhead | Medium | Medium to high | Low (invalidations) | | Best for | Large datasets | Tiered access patterns| Read-heavy workloads | ## Installation Add `:nebulex_distributed` to your dependencies in `mix.exs`: def deps do [ {:nebulex, "~> 3.0"}, {:nebulex_distributed, "~> 3.0"}, {:telemetry, "~> 0.4 or ~> 1.0"}, # For observability and monitoring {:decorator, "~> 1.4"}, # For declarative caching ] end The `:telemetry` (observability and monitoring cache operations) and `:decorator` (declarative caching) dependencies are optional but highly recommended. See each adapter's documentation for configuration and usage details. """ end