latency-audit

The HFT Validator. A ruthless CLI tool that audits Linux infrastructure against Tier 1 High-Frequency Trading standards.

The Problem

Default Linux kernels are tuned for throughput (web servers), not latency (trading).

A single misconfigured setting can cost you:

In HFT, 1 microsecond = $1M/year. These defaults are silent killers.

What It Checks

Kernel

• Swappiness (should be 0)
• Transparent Hugepages (should be never)
• Kernel preemption model

CPU

• Frequency Governor (should be performance)
• C-States (should be disabled)
• Core Isolation (isolcpus configuration)
• NUMA topology awareness

Network

• NIC Offloads (GRO/LRO/TSO should be OFF for latency-critical paths)
• IRQ affinity
• Ring buffer sizes
• UDP socket buffer drops (RcvbufErrors)
• NIC hardware discards (rx_missed_errors)

Hardware

• PCIe Link Width & Speed (validates NICs negotiated at max speed)
• Memory Channel Balance (detects asymmetric DIMM population)

Process

• Involuntary Context Switches (scheduler preemption)
• Major Page Faults (disk I/O detection)

Clock

• TSC reliability (constant_tsc, nonstop_tsc)
• Clocksource configuration

Installation

pip install latency-audit

Or install from source for the latest:

pip install git+https://github.com/padalan/latency-audit.git

Usage

Quick Audit (Read-Only)

latency-audit

Example output:

latency-audit v0.1.3

┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓
┃                           KERNEL CONFIGURATION                            ┃
┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛
  [PASS] swappiness = 0
  [FAIL] transparent_hugepages = always (should be: never)
  [PASS] kernel.sched_min_granularity_ns = 100000

┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓
┃                            CPU CONFIGURATION                              ┃
┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛
  [PASS] governor = performance (all cores)
  [FAIL] C-States enabled (max_cstate = 9, should be: 0)

JSON Output (for CI/CD)

latency-audit --json

{
  "score": 72,
  "checks": [
    {"name": "swappiness", "status": "pass", "value": 0},
    {"name": "thp", "status": "fail", "value": "always", "expected": "never"}
  ]
}

Check Specific Categories

# System-level checks
latency-audit --category kernel
latency-audit --category cpu
latency-audit --category network
latency-audit --category hardware

# Process-specific checks (requires --pid)
latency-audit --category process --pid 1234

Monitor a Running Process

# Check if your trading application has any scheduler preemptions or disk I/O
latency-audit --category process --pid $(pgrep trading_app)

Security

This tool is read-only by design. It:

• Reads /proc and /sys filesystem
• Reads sysctl values
• Inspects NIC settings via ethtool
• Never modifies any settings
• Never requires root (though some checks are more complete with it)

Contributing

Contributions are welcome! Please read CONTRIBUTING.md for guidelines.

# Clone and install dev dependencies
git clone https://github.com/padalan/latency-audit.git
cd latency-audit
pip install -e ".[dev]"

# Install pre-commit hooks
pre-commit install

# Run tests
pytest

Roadmap

• --fix mode with guided remediation
• Benchmark mode (measure actual latency)
• Docker container for isolated testing
• Ansible playbook generation
• Integration with Prometheus/Grafana

License

MIT © Nikhil Padala

_{Built with obsessive attention to microseconds.}