Skip to content

Latest commit

 

History

History
124 lines (94 loc) · 4.58 KB

README.md

File metadata and controls

124 lines (94 loc) · 4.58 KB

Replication Documentation Index

Welcome to the ThemisDB replication documentation. This directory serves as the central hub for all replication and high-availability (HA) documentation.

📚 Core Documentation

User Guides

  • replication-ha-guide.md - START HERE ⭐
    • Complete guide to High Availability replication
    • Deployment topologies (Active-Passive, Active-Active, Multi-DC)
    • Configuration examples and best practices
    • Monitoring, alerting, and operational procedures
    • Performance tuning and troubleshooting

Implementation Documentation

  • REPLICATION_IMPLEMENTATION_STATUS.md (German)

    • Detailed implementation status (~85% complete)
    • Component breakdown and file locations
    • Write-path flow diagrams
    • Build & test status
    • Prometheus metrics reference

  • replication_raid_plan.md

    • RAID 1/10 replication readiness plan
    • Current findings and implementation steps
    • Acceptance criteria and next actions
    • Integration status

🏗️ Architecture Overview

Module Organization

ThemisDB's replication system is organized across two main modules:

replication/ Module (High-Level Orchestration)

  • Location: include/replication/, src/replication/
  • Components:
    • ReplicationManager - Lifecycle and configuration management
    • MultiMasterReplicationManager - Multi-master coordination (see include/replication/multi_master_replication.h)
  • Responsibility: High-level replication strategies and orchestration

sharding/ Module (Low-Level Infrastructure)

  • Location: include/sharding/, src/sharding/
  • Components:
    • WALManager - Write-Ahead Log with LSN tracking
    • WALShipper - Batch-based WAL shipping to replicas
    • WALApplier - Idempotent WAL application
    • ReplicationCoordinator - Write concern enforcement (ONE/MAJORITY/ALL)
    • ReplicaTopology - Shard-to-replica mapping (RAID 1/10/5/6)
    • Consensus modules (Raft, Gossip, Paxos)
    • HealthMonitor - Replica health tracking
  • Responsibility: WAL-based replication mechanics, distributed consensus, topology management

Design Rationale: This separation allows the replication/ module to focus on business logic while sharding/ handles the complex distributed systems infrastructure needed for both replication and horizontal scaling.

Key Features

✅ Completed:

  • WAL-based replication with LSN tracking
  • Write concern support (ONE/MAJORITY/ALL)
  • RAID 1/10 topology support
  • Idempotent WAL application
  • Prometheus metrics integration
  • HTTP and gRPC replication endpoints
  • Leader election (Raft/Gossip/Paxos)
  • Health monitoring and failure detection

🚧 In Progress:

  • Multi-node endurance testing
  • RAID 5/6 implementation
  • Automatic failover enhancement

🔗 Related Documentation

Sharding & Distribution

System Architecture

Operations

🚀 Quick Start

  1. Start here: Read replication-ha-guide.md for a comprehensive overview
  2. Configuration: Check the configuration examples in the HA guide
  3. Implementation details: See REPLICATION_IMPLEMENTATION_STATUS.md for component-level details
  4. Deployment planning: Review replication_raid_plan.md for RAID configuration

📊 Implementation Status

Overall Progress: ~85% Complete

Completed Components ✅

  • WAL Manager, Shipper, Applier
  • Replication Coordinator
  • Replica Topology
  • HTTP/gRPC endpoints
  • Integration tests (8/8 passing)
  • Prometheus metrics

Remaining Work

  • Multi-node endurance testing
  • RAID 5/6 parity implementation
  • Automatic failover enhancements

🤝 Contributing

When updating replication documentation:

  1. Keep all three core documents in sync (HA guide, implementation status, RAID plan)
  2. Update cross-references when adding new documentation
  3. Follow the established structure for consistency
  4. Update this index when adding new replication docs

📝 License

See LICENSE for licensing information.