Open-source alternatives to KeyDB

Redis is a high-performance in-memory key-value store that functions as a distributed cache, message broker, and NoSQL database. It provides sub-millisecond read and write access to data stored in RAM and can operate as a vector database for indexing high-dimensional embeddings. The system supports a wide range of data storage and synchronization primitives, including the management of strings, hashes, lists, sets, and JSON documents. It enables real-time data operations through atomic transactions, hybrid persistence using snapshots and append-only logs, and high-availability configurations

ToyDB is a distributed SQL database that provides a system for storing and querying data across multiple nodes. It focuses on maintaining strong consistency and fault tolerance through the implementation of a distributed consensus algorithm. The project distinguishes itself by supporting historical data versioning, enabling time-travel queries to retrieve the state of the database from a specific point in the past. It utilizes multi-version concurrency control to manage ACID transactions and ensure data integrity during concurrent operations. The system covers relational data modeling with t

This project is a native Windows port of the Redis in-memory key-value store. It provides a high-speed database that maintains datasets in RAM while using periodic snapshots to disk for data persistence. The implementation includes a background system service wrapper, allowing the data store to be installed as a Windows service that starts automatically upon computer boot. It utilizes native Windows compilation to enable execution directly on the host operating system. The system covers in-memory data caching and local data persistence, ensuring that information is recovered after a process

PikiwiDB is a distributed NoSQL database and disk-based key-value store that serves as a Redis-compatible protocol server. It is designed to handle datasets larger than available system memory by utilizing a persistence engine that stores the full dataset on disk. The system employs a tiered storage model, caching frequently accessed hot data in memory while maintaining the primary volume on disk. It ensures high availability through a replicated data store architecture, using asynchronous binary logs to synchronize data between primary and secondary nodes. The project supports distributed d

immudb is a tamperproof database that maintains an immutable record of entries using cryptographic commit logging. It ensures verifiable database integrity by utilizing Merkle trees to generate membership and consistency proofs that detect unauthorized data alterations. The system employs a multi-model storage engine that unifies key-value, document, and relational data structures within a single immutable backend. It provides compatibility with the PostgreSQL wire protocol, allowing it to integrate with standard SQL clients, ORMs, and database tools. The project covers broad capabilities in

FoundationDB is an ACID-compliant distributed transactional key-value store. It functions as a scalable database engine that ensures strict serializability and data consistency across a cluster of servers using a shared-nothing architecture. The system is distinguished by its multi-region replication capabilities, allowing data to be synchronized across different datacenters for high availability and disaster recovery. It utilizes optimistic concurrency control to manage distributed transactions and employs a majority-based coordination system to maintain cluster state. The platform provides

CouchDB is a NoSQL document database that stores data as flexible documents and exposes a RESTful API for data management over HTTP. It functions as a distributed document store, synchronizing and replicating data across multiple nodes to ensure high availability and consistency. The system includes a full-text search engine that transforms database records into queryable documents, supporting sorting and pagination. Data synchronization is handled via multi-master replication, which exchanges revision histories to maintain consistency across distributed nodes. The database utilizes multi-ve

Hazelcast is a distributed data platform that combines an in-memory data grid with a stream processing engine to support real-time analytics and event-driven applications. It functions as a partitioned, distributed key-value store that replicates data across cluster nodes to provide low-latency access and high availability. The platform also serves as a distributed SQL query engine, allowing users to execute standard SQL statements against both in-memory datasets and external data sources. What distinguishes Hazelcast is its use of a distributed consensus subsystem to maintain strongly consis

NATS Server is a high-performance, lightweight messaging system designed for cloud-native applications, edge computing, and distributed microservices. It functions as a distributed publish-subscribe broker that routes messages using hierarchical, dot-separated subject strings, enabling decoupled communication between services without requiring centralized broker lookups. The system supports core messaging patterns including asynchronous publish-subscribe, request-reply, and load-balanced queue processing. The platform distinguishes itself through a decentralized architecture that eliminates t

Valkey is an in-memory, NoSQL database server designed for high-performance data storage and real-time state management. It operates as a distributed key-value store, maintaining datasets entirely within system memory to facilitate sub-millisecond response times for read and write operations. The system distinguishes itself through a single-threaded event loop that utilizes asynchronous I/O multiplexing to ensure high throughput. It supports high availability via master-replica replication and provides a decoupled communication model through a built-in publish-subscribe messaging pattern. To

Olric is a distributed data grid and in-memory key-value store that partitions and replicates data across a cluster of servers. It serves as a shared memory system for managing distributed maps, performing atomic operations, and acting as an in-memory data cache. The system provides a distributed locking mechanism for concurrency control and a pub-sub messaging system that broadcasts and routes messages over named channels across the cluster. The platform covers wide-ranging capabilities including cluster management and orchestration, data replication with configurable quorums, and automated

Bolt is a single-file embedded key-value store for Go applications. It is an ACID transactional database that organizes data in B+trees on disk to provide efficient sorted key retrieval and range scans. The system uses a memory-mapped model to map the database file directly into the process address space for fast random-access reads. The project distinguishes itself through a multi-version concurrency control architecture that allows multiple simultaneous readers to access a consistent snapshot of data without blocking a writer. It employs a single-writer multi-reader locking model and uses a

NeDB is a JavaScript embedded NoSQL document store designed for Node.js and the browser. It functions as an in-memory data store with the option to persist documents to a local file system, ensuring data survives application restarts. The project utilizes a MongoDB-compatible API to perform data operations, allowing it to serve as a lightweight document indexing system and a persistent file database without requiring a separate database server. Capabilities include querying, inserting, updating, and deleting documents, as well as the ability to create indexes on specific fields to accelerate

cr-sqlite is a multi-master database replication system that uses conflict-free replicated data types to ensure eventual consistency across distributed nodes. It provides the core capabilities for offline-first data synchronization, allowing multiple database instances to merge concurrent updates and reach a consistent state. The project distinguishes itself through a combination of CRDT-based data replication and a WASM-based database engine, enabling full SQL execution and state persistence within web browsers. It supports peer-to-peer replication and cross-tab synchronization, utilizing ca

Cinder is a high-performance Python runtime implementation based on CPython. It is designed as an execution environment optimized for large-scale distributed systems and cloud environments. The project integrates a distributed memory cache and an asynchronous memory layer to manage data across multiple network nodes. It also provides a native C extension framework for developing high-performance compiled modules that link directly into the interpreter memory space. The system covers capabilities for asynchronous data retrieval, large-scale execution, and the integration of embedded scripting

Groupcache is a distributed caching library designed to coordinate data retrieval and storage across a cluster of nodes. It functions as a peer-to-peer data store that uses consistent hashing to assign specific keys to canonical owners, ensuring that cached items remain predictable and accessible throughout the network. The system distinguishes itself through a request coalescing engine that merges concurrent requests for the same missing key into a single upstream fetch. This mechanism prevents redundant backend load by ensuring that only one process retrieves the required data while sharing

LMCache is a distributed key-value cache manager and tiering system designed to accelerate large language model inference. It functions as a tiered storage layer that offloads tensors from GPU memory to CPU RAM, local disks, or remote object stores, enabling the reuse of cached prefixes across different inference sessions and serving engines. The system differentiates itself through a disaggregated prefill-decode model, which separates prompt processing from token generation by transferring caches between distributed compute nodes. It utilizes peer-to-peer orchestration to share and retrieve

Dice is a low-latency key-value store based on Valkey that functions as a hierarchical storage engine. It combines a high-speed memory store with a tiered cache system to manage data across multiple storage levels. The system extends memory capacity by implementing a disk-backed cache that automatically persists evicted items to disk and restores them during cache misses. This storage tiering balances retrieval speed and operational cost by distributing data between fast memory and slower disk storage. The engine includes a query subscription service that monitors specific data patterns and

This project is a reference library of architectural blueprints, study materials, and design patterns for building scalable, high-availability distributed systems. It serves as a technical guide for scalability engineering, providing structural solutions for common engineering challenges. The repository focuses on distributed systems design, covering essential patterns for data replication, consensus algorithms, and transaction management. It distinguishes itself by offering detailed blueprints for specialized domains, including real-time data streaming, large-scale data storage, and high-ava

Sled is an embedded key-value store and ACID-compliant database designed for high-performance data persistence. It functions as a log-structured storage engine that organizes data using B+ trees to support efficient range queries and prefix scans. The engine implements a zero-copy data store model, utilizing epoch-based reclamation to provide direct references to cached values without memory allocations. It distinguishes itself through a combination of write-ahead logging, page cache optimizations to reduce write amplification on flash storage, and serializable transactions for atomic multi-k

Mooncake is a disaggregated large language model serving platform and distributed key-value store designed for high-performance inference infrastructure. It functions as a GPU memory orchestrator and KV cache management system that pools and transfers key-value caches across clusters to accelerate inference. The system distinguishes itself by separating the prefill and decode phases of inference into distinct hardware clusters to optimize resource utilization. It utilizes a high-performance RDMA distributed cache with zero-copy transfers to move data between compute nodes, bypassing the CPU t

Ignite is a distributed in-memory data grid and compute platform. It functions as a distributed SQL database and storage engine designed to store and process large datasets in RAM to minimize latency and increase calculation speed. The system is distinguished by a multi-tier storage engine that manages data placement across memory and disk to balance high-speed access with large capacity. It features a distributed compute grid that executes custom logic directly on the nodes where data resides to reduce network traffic. The platform provides a broad set of capabilities including ACID transac

RedisInsight is a graphical user interface and management tool for browsing, analyzing, and administering Redis databases. It provides a visual environment for exploring key-value data structures, managing database instances, and performing data analysis across different operating systems and deployments. The tool distinguishes itself by providing dedicated visual managers for complex operations, including a vector database manager for configuring embeddings and similarity searches, a query workbench for executing raw commands and Lua scripts, and a performance monitoring dashboard for tracki

Realm-Cocoa is a NoSQL mobile database engine and reactive object database designed for local data storage on mobile devices. It serves as a non-relational alternative to Core Data and SQLite, storing data as objects rather than tables. The system functions as an encrypted local store that protects sensitive application data using encryption. It provides reactive data synchronization, allowing application objects and user interfaces to update automatically when the underlying database changes.

This project is a containerized search infrastructure designed to deploy a privacy-focused metasearch engine. It acts as a self-hosted search proxy that aggregates results from multiple external web, image, and academic search providers while anonymizing requests and stripping trackers to protect user identity. The system utilizes Docker to orchestrate the search instance, integrating caching mechanisms and reverse proxy support to ensure a private and efficient search environment. It employs a modular adapter-based integration to standardize diverse external API responses and a processing pi

Tile38 is an in-memory geospatial database that uses the Redis protocol for communication and query execution. It serves as a distributed spatial store for points and polygons, featuring high availability through leader-follower replication and disk-based persistence. The system includes a real-time geofencing engine that monitors virtual geographic boundaries and triggers webhooks when objects enter or exit specified areas. It further distinguishes itself with an embedded Lua scripting engine for server-side data transformations and a built-in vector tile server for efficient map visualizati

This is a mobile object database and NoSQL local data store that replaces relational tables with a schema-based model. It functions as a reactive data store, using live object observations and change notifications to trigger automatic user interface refreshes. The system provides built-in mobile cloud data synchronization to keep local datasets consistent with a remote server across multiple devices. It also includes security features for encrypted local storage, protecting sensitive on-disk data using at-rest encryption keys and fine-grained access control. Broad capabilities include object