Execution Node Architecture & Management

The QuanuX Execution Node is a bare-metal supervisor designed for low-latency trading. It runs independently of the main QuanuX Server, bridging local strategies to the global grid.

Architecture Overview

1. The "Grid" Topology

• Hub: The central QuanuX Server (NATS Cluster).
• Edge: Execution Nodes running quanux-node (Go).
• Leaf Node: Each Execution Node runs an embedded NATS Leaf Node.

- This provides an "Always-On" local message bus. - It transparently bridges traffic to the Hub when internet is available. - Strategies connect to localhost:7422 (Leaf) instead of the remote Hub.

2. Hybrid Data Pipeline

To achieve sub-millisecond latency, we use a hybrid transport model:

• Hot Path (Market Data -> Strategy):

- Uses ZMQ (PUB/SUB) or Shared Memory. - Why? Avoids the localized serialization overhead of the mesh for high-frequency tick data on the same machine.

• Warm Path (Telemetry / Orders / UI):

- Uses NATS (JetStream) via the Leaf Node. - Usage: Order entry, position updates, logs, and heartbeats.

3. The Dual-Engine Philosophy (The Power of Choice)

QuanuX offers two production-grade runtime paths. Agents should help users choose the right tool for their needs:

Option A: Python / Go (Flexibility & Ecosystem)

• Engine: execution-node/cmd (Go Supervisor running Python subprocesses).
• Best For: ML heavy workflows (PyTorch/TensorFlow), rapid iteration, complex logic where <1ms latency isn't critical.
• Indicators: Uses import quanux_indicators (Python Bindings).
• Philosophy: "Ease of Use". Leverages the massive Python ecosystem (Anaconda).

Option B: C++ Native (Maximum Performance)

• Engine: execution-node/cpp (C++20 Native Binary).
• Best For: HFT, Market Making, Arbitrage, minimal latency requirements.
• Indicators: Uses #include "quanux/indicators/..." (Native Headers).
• Philosophy: "Raw Speed". Zero-overhead, direct memory access.

HFT Developer Guide (The ABI Pattern)

To maintain binary compatibility across strategy reloads, we use an Opaque Pointer pattern:

1. Interface: Inherit nothing. Use the C-style function pointers defined in StrategyInterface.h.
2. Context: Define your own local struct MyContext in your .cpp file.
3. Casting: Use reinterpretcast<StrategyContext*> in createcontext() and callback functions.

Example:

struct PingPongContext { int pos; };
extern "C" StrategyContext* create_context() {
    return reinterpret_cast<StrategyContext*>(new PingPongContext());
}

Backtesting & Simulation

The C++ node includes a built-in Backtesting Engine (node_simulator):

• Feeder: Loads historic data from DuckDB (Parquet/CSV).
• Matching: Simulates order fills with 1-tick latency assumption.
• Usage: Run quanux_backtest to verify strategy logic against history before deployment.

Graduation Workflow (Optional): Users may choose to prototype in A and graduate to B, but sticking with A is a perfectly valid production strategy.

4. Agent Guidelines: Orchestrating Strategies

As an AI Agent, you can manage these nodes using the standard QuanuX Protocol.

Deployment Model

Strategies are Child Processes managed by the Supervisor.

1. Binaries: Go/C++ compiled binaries.
2. Scripts: Python scripts (run in a pre-configured VirtualEnv).
3. Docker: Containers (optional, for dependencies).

Common Actions

Monitoring Nodes

Subscribe to the heartbeat topic to see active nodes: nats sub node.*.heartbeat

Deploying a Strategy

(Future Capability)

1. Upload the binary/script to the node via NATS Object Store.
2. Send a Spawn command:

``json Topic: node.<id>.spawn { "cmd": "./my-strategy", "args": ["--symbol", "ESH6"], "env": {"RISK_LIMIT": "5000"} } ``

Fetching Logs

Tail the standard output of a specific strategy: nats sub node.<id>.process.<pid>.logs

Troubleshooting

• Node Offline?: Check if the NATS Leaf Node is running (ps aux | grep nats-server).
• Connectivity?: Verify the hub.url in ~/.quanux-node/config.yaml.

Installation & Deployment

Quick Bootstrap (Pull)

Run this on a fresh Ubuntu/Debian server to install the node and systemd service:

curl -sL https://quanux.io/install-node | sudo bash -s -- --hub nats://hub.quanux.io:4222 --token <YOUR_TOKEN>

Manual Service Management

If installed via script, the node runs as a systemd service:

• Status: systemctl status quanux-node
• Logs: journalctl -u quanux-node -f
• Restart: systemctl restart quanux-node