Open-source alternatives to Etcd

ZooKeeper is a distributed coordination service that provides a centralized system for managing configuration, naming, and synchronization across a cluster of distributed processes. It functions as a cluster consensus service, a distributed configuration store, and a distributed lock manager to maintain a consistent state across multiple network nodes. The service implements a consensus protocol to ensure data consistency and uses a replicated state machine to maintain identical copies of the system state across all servers. It provides a distributed lock management system to coordinate exclu

Dragonboat is a Go implementation of the Raft consensus protocol designed to maintain consistent state across a distributed cluster of nodes. It provides a library for building distributed state machines that ensure data integrity and fault tolerance during system failures. The project distinguishes itself through a multi-group Raft implementation, which partitions data across independent consensus groups to distribute workloads and increase overall system processing capacity. It also incorporates mutual TLS to encrypt inter-node communication and verify the identity of cluster members. The

This is a Raft consensus library and distributed consensus engine implemented in Go. It provides the primitives necessary to build fault-tolerant distributed services by implementing a replicated state machine that ensures a group of servers agree on a shared system state through leader election and log replication. The project distinguishes itself through a pluggable architecture for storage backends and snapshot storage, decoupling the consensus logic from physical persistence. It includes specialized mechanisms for leadership transfer, protocol version management to support rolling upgrade

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

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

TiDB is a horizontally scalable, distributed SQL database designed to provide consistent transactional storage and high-performance analytical processing within a single unified architecture. It utilizes a decoupled compute-storage design and a distributed key-value storage layer to ensure horizontal scalability and efficient range-based queries. By employing a consensus-based replication algorithm, the system maintains high availability and automatic failover across multiple nodes and geographical regions. The platform distinguishes itself through its hybrid transactional and analytical proc

TiKV is a cloud-native distributed transactional key-value store and storage engine. It provides a distributed database designed for horizontal scalability and strong consistency across a cluster of physical nodes. The system uses a Raft-based consensus mechanism to maintain data availability and state synchronization. It ensures ACID compliance for distributed transactions through a two-phase commit workflow and manages data distribution via multi-Raft sharding. The engine handles massive datasets using automated range splitting and cluster load balancing to distribute data across different

This project is a comprehensive Java backend engineering guide and technical reference focused on high-concurrency design, distributed systems, and microservices architecture. It provides detailed strategies for decomposing monolithic applications, managing service discovery, and implementing the architectural patterns required for scalable backend environments. The repository distinguishes itself through an extensive collection of big data algorithmic references and database scaling strategies. It covers memory-efficient techniques for analyzing massive datasets, such as Top-K element extrac

brpc is a high-performance C++ RPC framework and network programming library designed for building distributed systems. It functions as a multi-protocol RPC server capable of hosting and detecting multiple communication protocols, including gRPC, Thrift, HTTP, Redis, and Memcached, on a single TCP port. The project distinguishes itself through high-throughput data transport and memory efficiency, utilizing RDMA-based transport to bypass the kernel TCP stack and zero-copy memory management to eliminate data duplication. It also implements the Raft algorithm for consensus-based state replicatio

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

Cassandra is a distributed NoSQL database and wide-column store designed for high availability and linear scalability. It functions as a fault-tolerant distributed system that utilizes an LSM-tree storage engine to optimize write throughput and manage massive datasets. The system is a CQL-compliant database, using a structured query language to manage and retrieve tabular data stored across multiple nodes. It organizes information into rows and columns based on a flexible schema and primary keys. The project provides capabilities for horizontal database scaling, distributed data partitioning

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

Consistent is a Go library that implements consistent hashing with bounded loads to distribute data keys across nodes in a distributed system. It provides a mechanism for mapping keys to cluster members that minimizes data movement during membership changes while preventing performance hotspots. The library distinguishes itself by enforcing strict capacity limits on individual nodes, ensuring that no single member becomes overwhelmed by excessive key assignments. It supports virtual node mapping to distribute physical capacity across the hash ring, allowing for granular control over load bala

Badger is an embeddable key-value store written in Go that provides persistent data storage for byte keys and values. It is a persistent database that utilizes a tiered LSM tree storage model to optimize disk storage and retrieval efficiency. The system features an ACID transaction engine that ensures data integrity through serializable snapshot isolation and multi-version concurrency control. It also provides an encrypted key-value store with data-at-rest encryption and a managed encrypted key registry to secure stored information. The engine covers a broad set of capabilities including hig

grpc-go is a Go language implementation of the gRPC framework, providing a remote procedure call library for high-performance service communication. It uses the HTTP/2 protocol to execute functions on remote servers as if they were local methods and utilizes protobuf service bindings to generate type-safe client and server code. The project features a bidirectional streaming transport that supports asynchronous, full-duplex message streams between clients and servers. This networking layer allows for various communication patterns, including client-to-server and server-to-client streaming, to

rpcx is a high-performance remote procedure call framework for building scalable microservices in Go. It functions as a binary protocol RPC system and a service mesh, providing the necessary infrastructure for low-latency inter-service communication and distributed cloud environments. The project features a cross-language service gateway that provides an HTTP entry point, allowing clients written in any programming language to invoke Go remote services via protocol translation. It also includes a specialized RPC traffic analyzer for capturing and analyzing binary packets to debug network comm

TinyKV is a distributed key-value store designed for storing and retrieving data across multiple nodes with high availability. It functions as a distributed database system that incorporates a dedicated key-value storage engine for raw data persistence and retrieval on individual nodes. The project includes a Raft consensus engine to ensure data consistency and fault tolerance across a cluster of servers. It also features a distributed transaction manager that coordinates atomic commits and concurrency control to maintain data integrity across shards. The system covers cluster membership man

Pigsty is a full-stack orchestration suite for deploying, monitoring, and managing high-availability PostgreSQL clusters and their supporting infrastructure. It functions as a cluster management platform and high-availability suite that automates failover, manages virtual IPs, and ensures data consistency through distributed consensus. The project distinguishes itself by providing a comprehensive database infrastructure-as-code framework and a dedicated observability stack. It incorporates a backup and recovery manager supporting point-in-time recovery via S3-compatible object storage, alongs

sofa-jraft is a Java implementation of the Raft consensus algorithm. It serves as a distributed consensus engine and linearizable state machine designed to ensure high availability and data consistency across a cluster of nodes. The project provides a replicated key-value store and a coordination engine for managing distributed state. It distinguishes itself through support for multi-group consensus sharding to distribute traffic and a service provider interface that allows for custom log storage and entry encoding implementations. The system covers a wide range of distributed capabilities,

rqlite is a distributed relational database that replicates SQLite data across a cluster using the Raft consensus algorithm. It functions as a fault-tolerant storage system that provides high availability and a web API for executing SQL queries and managing relational data without requiring native database drivers. The system distinguishes itself by using an HTTP SQL interface to expose database operations and cluster management. It features a real-time change data capture stream that pushes database mutations to external HTTP endpoints via webhooks and supports the scaling of read throughput

Patroni is a high availability manager and cluster orchestrator for PostgreSQL. It functions as an automatic failover controller and replication manager that ensures continuous database availability by automating leader election and promoting standby nodes during failures. The system maintains a consistent cluster state by acting as a distributed consensus coordinator. It synchronizes configuration and manages leader elections through integration with distributed configuration stores such as etcd, ZooKeeper, or Consul. Its broader capabilities include managing both synchronous and asynchrono

Nebula is a distributed graph database designed for storing and querying massive volumes of interconnected vertices and edges across a horizontally scalable cluster. It functions as a Kubernetes-native database and a distributed graph analytics engine, utilizing a Raft-based distributed store to ensure strong consistency and high availability. The system features an OpenCypher query engine for performing complex graph traversals and pattern matching. It distinguishes itself with a decoupled compute-storage architecture and a shared-nothing distributed design, allowing query processing and dat

This project provides a comprehensive guide and set of scripts for deploying and configuring a production-ready Kubernetes cluster from scratch. It centers on establishing a functional environment by installing core management components, storage, and networking across multiple nodes. The implementation emphasizes high availability for the control plane, utilizing layer-4 load balancing and leader election for the API server, scheduler, and controller manager. It further ensures reliability through the deployment of a distributed key-value store for persistent runtime data. The project cover

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

Nomad is a distributed workload orchestrator and infrastructure automation platform designed to manage the lifecycle of applications across large-scale, heterogeneous environments. It functions as a multi-cloud orchestration engine, providing a unified control plane to deploy, scale, and govern containers, virtual machines, and legacy applications. By utilizing declarative job specifications, the system ensures infrastructure convergence and maintains the desired state across distributed data centers and geographic regions. The platform distinguishes itself through a flexible, plugin-based ar

Incus is a unified orchestration platform for managing system containers, OCI application containers, and virtual machines through a single control plane. It brings together cluster infrastructure management, secure multi-tenancy, software-defined networking, and pluggable storage backend orchestration into one cohesive system exposed via a full REST API and command-line interface. What distinguishes Incus is its ability to run multiple instance types side by side—full Linux system containers, OCI application containers, and QEMU virtual machines—all managed with consistent tooling. Networkin

dkron is a distributed cron service and high availability task scheduler designed to execute scheduled commands across a cluster of servers. It functions as a scalable replacement for traditional cron by synchronizing task execution across multiple nodes to eliminate single points of failure. The system ensures fault tolerant task automation and high availability cron management through a distributed architecture. It utilizes a replicated state machine and consensus to maintain synchronized job schedules and provides automatic failover and redundancy. The platform covers distributed job sche