Open-source alternatives to Sled

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

This project is a feature-rich Go client library designed for interacting with Redis. It serves as a comprehensive interface for managing remote data stores, enabling developers to execute standard database commands, handle complex data structures, and perform asynchronous operations within Go applications. The library distinguishes itself through its support for advanced Redis capabilities, including connection pooling, pipelining, and transactional integrity. It provides specialized primitives for managing distributed clusters, including automated topology updates and request routing to sha

RoseDB is a persistent key-value database and log-structured storage engine. It functions as a lightweight storage system that utilizes a log-structured hash table and a Bitcask engine implementation to provide fast data retrieval and disk-backed persistence. The system operates as an atomic transaction engine, grouping multiple read and write operations into single units to maintain data consistency. It handles data through a key-value model that supports individual insertions, lookups, and deletions. The database provides capabilities for batch data processing and atomic updates. Additiona

FASTER is a high-throughput key-value store that combines an in-memory data store with a hybrid memory-disk storage engine, enabling datasets larger than available RAM. It uses a latch-free, cache-optimized index for concurrent point lookups and heavy updates, and records all mutations to a persistent append-only log on disk with checksum validation and group-commit checkpointing for crash recovery. The system supports multi-key transactional workloads through atomic multi-key locking, ensuring transactional consistency without coarse-grained contention. It exposes the key-value store to remo

RocksDB is a high-performance, embeddable persistent key-value library and storage engine based on Log-Structured Merge-trees. It is designed to provide durable storage for large-scale datasets, integrating directly into applications to manage data on flash and RAM-based hardware. The engine is distinguished by its focus on minimizing read and write amplification through multi-threaded compaction and custom memory allocators. It features specialized optimizations for flash storage, including support for zoned block devices, and provides the ability to extend store behavior via external plugin

LiteDB is a serverless, embedded NoSQL document database for .NET applications. It persists data into a single portable file, functioning as a BSON data store that resides within the application process rather than running as a separate server. The system is ACID compliant, utilizing write-ahead logging to ensure atomic, consistent, isolated, and durable transactions. It includes built-in encryption to provide secure local data storage and protect files on disk from unauthorized access. The project covers object-document mapping to convert classes into document formats, indexed search capabi

bbolt is an ACID-compliant embedded key-value store for Go applications. It persists all data in a single memory-mapped file on disk, organizing information using B+ trees to facilitate sorted key iteration and efficient range queries. The project distinguishes itself through a hierarchical data organization model, allowing buckets to be nested within other buckets to create a tree-like structure. It employs a single-writer, multi-reader locking mechanism and copy-on-write transactions to ensure serializable isolation and data integrity. The system includes comprehensive data management capa

Godis is a Redis-compatible in-memory database and distributed key-value store. It functions as a replicated data store and distributed message broker, implementing the Redis protocol to manage complex data structures in memory. The system provides a geospatial indexing engine for proximity-based queries and distance calculations. It ensures high availability and data durability through master-slave replication and write-ahead logging. The project covers a wide range of capabilities including the management of strings, hash maps, lists, and sorted sets. It supports distributed data clusterin

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

H2 is a JDBC-compliant relational database management system written in Java. It functions as an embeddable SQL database that can run directly within an application process to remove network latency, or as an in-memory database for high-performance volatile storage. It also includes a web-based console for executing SQL commands and administering schemas. The system is characterized by its flexible deployment modes, including a standalone server mode for remote TCP/IP access and a mixed mode for simultaneous local and remote connectivity. It features a dialect emulation layer and compatibilit

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

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

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

LedisDB is a distributed NoSQL key-value store built in Go. It functions as a high-performance database server that persists simple values, counters, and complex data structures using pluggable storage engines. The system implements the Redis protocol to maintain compatibility with existing client libraries and drivers, while also providing an HTTP interface that exposes database functions through JSON, BSON, or msgpack formats. It includes an embedded virtual machine to execute custom server-side Lua scripts for complex operations. The platform supports high availability through data replic

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

Levelup is a sorted key-value storage system that saves and retrieves data using byte arrays as keys and values. It provides a compatibility layer for Node.js and browsers that offers a unified interface for storage backends compliant with a specific abstract standard. The project features an atomic batch write engine to execute multiple write and delete operations as a single unit for data consistency. It includes a range-based data streamer for reading keys and values as continuous sequences and an event-driven storage monitor to track asynchronous updates and state changes. The system cov

NutsDB is an ACID-compliant, embedded transactional storage engine that functions as both a disk-backed key-value store and an in-memory data structure store. It provides atomic and serializable transactions with commit and rollback capabilities to ensure strict data consistency for applications requiring a lightweight persistence layer. The engine distinguishes itself by supporting a variety of complex data types, including lists, sets, and sorted sets, alongside standard byte-slice storage. It implements a transactional storage model featuring hot backups and a compaction algorithm to maint

React Native AsyncStorage is a persistent key-value storage library designed for React Native applications. It provides a unified local storage interface that works identically on both iOS and Android, ensuring saved data remains available across app restarts and when the device has no network connectivity. The library uses an asynchronous background I/O queue to handle all storage operations without blocking the JavaScript thread, communicating with native storage engines through React Native's bridge protocol. It includes a serialization layer that converts JavaScript values to strings for

SQLite is a serverless relational database engine and C-based library that stores data in a single local disk file. It functions as an embedded SQL database, integrating directly into applications without the need for a separate server process. The engine includes specialized capabilities for full-text search indexing and spatial data querying using R-Tree structures for geographic or geometric coordinate ranges. The system provides broad support for SQL data manipulation, database recovery and repair, and change tracking for synchronizing modifications between databases. It also features a

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

PostgreSQL is an object-relational database management system designed for the persistent storage and retrieval of structured information. It functions as an ACID-compliant database server, utilizing standard query language protocols to maintain data consistency and reliability across large-scale application datasets. The system distinguishes itself through an extensible architecture that allows for the definition of custom data types, operators, and indexing methods. It employs multi-version concurrency control to enable simultaneous read and write operations without blocking, supported by a

etcd is a distributed, strongly consistent key-value store designed to provide reliable storage for critical system metadata and coordination primitives. It functions as a distributed consensus engine, utilizing a replicated log and leader-based state machine to ensure that all nodes in a cluster maintain a synchronized view of data. By providing atomic operations and linearizable reads and writes, it serves as a foundational component for distributed systems requiring high availability and fault tolerance. The system distinguishes itself through its multi-version concurrency control, which e

RoseDB is an embedded key-value database and log-structured storage engine. It functions as a library-based database that runs within an application process to provide local data persistence without the need for a separate database server. The project implements a Bitcask-style store, utilizing an append-only log format to maximize write throughput and minimize seek time. It ensures data consistency by grouping multiple read and write operations into single atomic units. The storage architecture relies on an in-memory key index for constant-time lookups and uses segment-based file management

Sonic is a high-performance, lightweight search backend designed to provide real-time full-text search and autocomplete capabilities for applications. It functions as a persistent indexing server that maps text terms to object identifiers, allowing developers to integrate rapid search functionality without storing raw document content directly within the search engine. The system distinguishes itself through a specialized graph-based index that enables real-time word prediction and typo correction. Communication is handled via a custom, low-latency binary protocol over raw TCP sockets, which

SurrealDB is a multi-model database engine designed to store and query document, graph, relational, and vector data within a single ACID-compliant platform. It functions as an AI-native data store, integrating vector search, graph traversal, and machine learning model execution directly into its query layer. By providing a unified declarative query language, the platform eliminates the need for external middleware to synchronize data across different storage models. The platform distinguishes itself through its ability to manage agent memory and complex workflows natively. It allows developer

This project serves as a comprehensive technical reference for the architecture and design of data-intensive applications. It provides a structured analysis of the fundamental principles required to build reliable, scalable, and maintainable software systems, covering the core trade-offs inherent in modern data infrastructure. The repository explores the mechanics of distributed data management, including strategies for replication, partitioning, and achieving consensus across multiple nodes. It details the design of storage engines, indexing techniques, and transaction management models, whi