implementation-checklist.md

Next-Gen Distributed Search Engine - Implementation Checklist

Project Overview

• Goal: Build a distributed, high-performance search and vector database
• Tech Stack: Go (Coordinator/DataNode) + Rust (Storage Engine) + etcd (Metadata)
• Architecture: Coordinator-based clustering with LSM-tree storage

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Phase 0: Project Structure & Initial Setup

Repository Setup

• Initialize monorepo structure
• Set up Go modules (go.mod files)
• Set up Rust workspace (Cargo.toml)
• Create .gitignore for Go and Rust
• Set up build scripts and Makefile
• Configure CI/CD pipeline (GitHub Actions/GitLab CI)

Development Environment

• Install required tools: Go, Rust, protoc, etc.
• Set up development containers (optional)
• Configure IDE/editor settings
• Set up linting and formatting tools

Documentation Setup

• Create README.md with project overview
• Set up API documentation generation pipeline
• Create development guidelines
• Set up changelog and versioning strategy

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Phase 1: Local-Only MVP

1.1 Protocol Buffers & API Contracts

• Define core proto files:
  • coordinator.proto (REST API definitions)
  • datanode.proto (gRPC service definitions)
  • storage.proto (Storage Engine interface)
  • common.proto (shared types)
• Set up protoc plugins and code generation
• Configure gRPC reflection
• Set up OpenAPI generation from proto files
• Generate Go and Rust client/server code

1.2 Schema DSL Specification

• Define schema DSL in YAML/JSON format
• Create Go structs for schema validation
• Implement schema parsing and validation
• Add support for field types: text, keyword, double, vector
• Implement analyzer support (standard, custom)

1.3 Storage Engine (Rust)

• Set up Rust project structure
• Implement LSM-tree core components:
  • Memtable (in-memory storage)
  • WAL (Write-Ahead Log)
  • SSTable (on-disk storage)
  • Bloom filters for SSTables
• Implement compaction logic:
  • L0 flush from Memtable to SSTable
  • L1/L2 merge operations
  • Background compaction scheduler
• Implement inverted index for text fields
• Implement vector index (HNSW)
• Create FFI interface for Go integration
• Add unit tests for all components

1.4 Data Node (Go)

• Set up Go module structure
• Implement gRPC server (DataNodeService)
• Create FFI bindings to Rust storage engine
• Implement local query execution
• Add result aggregation logic
• Implement bulk indexing operations
• Add health check endpoints
• Add unit and integration tests

1.5 Coordinator (Go)

• Set up Go module structure
• Implement REST API server:
  • POST /index/{index}/_doc (document ingestion)
  • POST /index/{index}/_search (search queries)
  • GET /index/{index}/_schema (schema management)
• Implement gRPC client for DataNode communication
• Add query parsing and validation
• Implement query routing logic
• Add result aggregation and ranking
• Add OpenAPI documentation
• Add unit and integration tests

1.6 Integration Testing

• Create Docker Compose setup for local testing
• Implement end-to-end tests:
  • Document ingestion flow
  • Search query flow
  • Schema management
• Add performance benchmarks
• Test Go-Rust FFI integration

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Phase 2: Persistence, Compaction, Metadata

2.1 Enhanced Storage Engine (Rust)

• Implement durable WAL with crash recovery
• Add SSTable serialization/deserialization
• Implement snapshot isolation for consistent reads
• Add background compaction with configurable policies
• Implement data integrity checks
• Add storage metrics and monitoring

2.2 Metadata Store Integration

• Set up etcd client integration
• Implement cluster metadata management:
  • Node registration and discovery
  • Schema storage and versioning
  • SSTable metadata tracking
  • Shard allocation information
• Add metadata backup and recovery
• Implement metadata consistency checks

2.3 Data Durability

• Implement point-in-time backup mechanism
• Add data recovery procedures
• Implement WAL replay on startup
• Add data integrity validation

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Phase 3: Clustering & Distribution

3.1 Cluster Coordination

• Implement node discovery via etcd
• Add consistent hashing for sharding
• Implement shard allocation and rebalancing
• Add leader election for shard replicas
• Implement query fanout to multiple DataNodes
• Add result aggregation across shards

3.2 Fault Tolerance

• Implement health checks and failure detection
• Add automatic failover mechanisms
• Implement shard replication
• Add network partition handling
• Implement graceful shutdown procedures

3.3 Load Balancing

• Add load balancing across DataNodes
• Implement query routing optimization
• Add capacity planning and monitoring
• Implement backpressure mechanisms

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Phase 4: Observability, Security, SDKs

4.1 Observability

• Add Prometheus metrics for all components
• Implement OpenTelemetry tracing
• Add structured logging
• Create admin dashboard (Grafana integration)
• Add alerting rules and notifications
• Implement slow query logging

4.2 Security

• Implement TLS for all communication
• Add API key authentication
• Implement role-based access control (RBAC)
• Add audit logging for sensitive operations
• Implement rate limiting and throttling
• Add security scanning in CI/CD

4.3 Client SDKs

• Create Go SDK with examples
• Create Python SDK with examples
• Create JavaScript/TypeScript SDK
• Add SDK documentation and tutorials
• Implement SDK testing and validation

4.4 API Documentation

• Auto-generate OpenAPI specs from proto files
• Create interactive API documentation (Swagger UI)
• Add code examples for all endpoints
• Create API versioning strategy
• Add backward compatibility guarantees

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Phase 5: Packaging & Deployment

5.1 Containerization

• Create Dockerfiles for all components
• Optimize Docker images for production
• Add multi-stage builds for efficiency
• Implement Docker Compose for development
• Add container security scanning

5.2 Kubernetes Deployment

• Create Helm charts for deployment
• Implement K8s Operator for cluster management
• Add service mesh integration (optional)
• Create K8s manifests for all components
• Add K8s monitoring and logging

5.3 Production Readiness

• Add production deployment guides
• Implement backup and restore procedures
• Add disaster recovery documentation
• Create operational runbooks
• Add performance tuning guides

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Testing Strategy

Unit Testing

• Storage Engine (Rust): LSM-tree, compaction, vector search
• Data Node (Go): gRPC server, query execution
• Coordinator (Go): REST API, query routing
• Common components: schema validation, analyzers

Integration Testing

• Coordinator ↔ DataNode communication
• Go ↔ Rust FFI integration
• End-to-end ingest and search flows
• Schema management and evolution

Performance Testing

• Query throughput and latency benchmarks
• Ingestion performance under load
• Memory and CPU usage profiling
• Scalability testing with multiple nodes

Chaos Testing

• Node failure simulation
• Network partition testing
• Metadata store failure scenarios
• Data corruption and recovery testing

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Documentation

Technical Documentation

• Architecture design documents
• API reference documentation
• Schema DSL specification
• Deployment and operations guides
• Performance tuning documentation

User Documentation

• Getting started guide
• Tutorials and examples
• Best practices guide
• Troubleshooting guide
• FAQ and common issues

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Quality Assurance

Code Quality

• Set up linting and formatting tools
• Implement code review guidelines
• Add automated code quality checks
• Set up dependency vulnerability scanning
• Implement security best practices

Release Management

• Set up semantic versioning
• Create release notes template
• Implement automated release process
• Add changelog maintenance
• Set up release testing procedures

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Future Enhancements (Post-MVP)

Advanced Features

• SQL query support
• GraphQL API
• Auto-indexing and schema inference
• Multi-tenant support
• Edge deployment variant

Performance Optimizations

• Query result caching
• Advanced query planning and optimization
• Compression algorithms for storage
• Memory-mapped file optimizations

Ecosystem Integration

• Elasticsearch compatibility layer
• Logstash/Beats integration
• Grafana dashboard templates
• Prometheus alerting rules

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Notes

• Update this checklist as implementation progresses
• Add specific dates and assignees for each task
• Track dependencies between tasks
• Regular review and update of priorities