AzothBalancer - Resilient RPC Infrastructure for Decentralized Solvers

AzothBalancer is a high-performance, transport-agnostic JSON-RPC load balancer in Rust. It provides reliability, performance, and cost-efficiency for blockchain infrastructure, focusing on the demanding workloads of CoW Protocol solvers. The project is currently stable at v0.3.0 with a well-tested foundation.

Core Functionality

• 3-Tier Endpoint Routing: Prioritizes requests based on configurable weights (Tier 1 ≥100 → Tier 3 1–49)
• Health Monitoring & Failover: Automatic cooldown for failing or rate-limited endpoints
• Per-Endpoint Rate Limiting: Supports burstable limits to prevent provider throttling
• Batch Request Handling: Handles JSON-RPC batch requests safely
• Hot Configuration Reloading: /reload endpoint updates endpoints without downtime
• Prometheus Metrics: /metrics exposes health and performance stats
• Graceful Shutdown: Completes in-flight requests before termination

Planned Enhancements

• transaction-type aware routing: Route sensitive RPC methods (e.g., eth_sendRawTransaction) to secure endpoints (eg. MEV Blocker)
• Response Caching: Cache common RPC calls (eth_call, eth_getLogs) to reduce latency
• Enhanced Security: HTTPS/TLS termination and optional API key authentication
• Production Dashboards: Grafana dashboards for monitoring performance and health

Ecosystem Impact

• Increase Solver Reliability: Reduce infrastructure-related settlement failures
• Lower Operational Costs: Optimized routing for premium and free endpoints
• Lower Barrier to Entry: Enable new solver operators to run reliable infrastructure easily
• Open-Source Contribution: Reusable component for CoW ecosystem solvers

Architecture Highlights

• Async Rust: Built with Tokio, Axum, Reqwest for performance and correctness
• Tiered Fallback Strategy: Strict priority order with Tier 1 → Tier 3 fallback
• Exponential Backoff: Progressive cooldown for repeatedly failing endpoints
• Thread-Safe State: Arc<RwLock<...>> ensures correctness under high concurrency
• Comprehensive Tests: 20+ unit tests covering routing, configuration, and error handling

Diagram

graph TB
    A[Client Request] --> B[AzothBalancer]
    B --> C{Tier Selection}
    C -->|Tier 1| D[Local Endpoints]
    C -->|Tier 2| E[Premium RPCs]
    C -->|Tier 3| F[Free Endpoints]
    D --> G[Health Check]
    E --> G
    F --> G
    G --> H[Response]

Quick Start

git clone https://github.com/AzothSolver/azoth-balancer.git
cd azoth-balancer
cp config.example.toml config.toml
cargo build --release
./target/release/azoth-balancer --config config.toml

Default server: 0.0.0.0:8549

CLI & Multiple Configs

• Custom Config Path: Specify a configuration file:

./target/release/azoth-balancer --config config.toml
# or
cargo run --release -- --config config.toml

• Chain-Specific Configs: Maintain separate configs for different networks:

config-eth.toml       # Ethereum RPC endpoints
config-arbitrum.toml  # Arbitrum RPC endpoints
config-solana.toml    # Solana RPC endpoints

• Start with a specific network config:

./target/release/azoth-balancer --config config-arbitrum.toml

Note: Each config must contain RPC endpoints from the same chain.

Docker

• Dockerfile included
• docker-compose.yml available:

docker-compose up --build

License

MIT or Apache 2.0

• LICENSE-MIT
• LICENSE-APACHE

Repository

• GitHub: AzothBalancer

Contact

For questions, suggestions, or contributions, please open an issue on GitHub Issues.