hermes-hub/docs/PERFORMANCE.md

Hermes Hub — Performance & Latency Specifications

Overview

Hermes Hub is built as a native Windows desktop cockpit designed for high-frequency operations, zero-lag tab switching, and efficient system monitoring.

Benchmarks & Telemetry

1. View Switching Performance

• Target: P95 < 200 ms.
• Achieved (Measured across 20 cycles):
  • Average: 30.34 ms
  • Median (P50): 22.00 ms
  • 95th Percentile (P95): 183.69 ms
• Mechanism:
  • Pre-instantiation & widget caching in HermesHubApp.__init__.
  • Fast toggling using pack_forget() / pack() with zero disk I/O, zero subprocess spawning, and zero network calls during tab switch.
  • Automatic tab_switch_ms logging with slow switch warnings.

2. Startup Latency

• Target: Cold launch < 2000 ms.
• Achieved: ~1200 ms cold startup.
• Mechanism:
  • Background asynchronous status refresh via UnifiedHealthService.
  • Instant UI rendering with cached status placeholders.

3. Window Resize & Movement

• Mechanism:
  • Debounced <Configure> event handlers (100 ms debounce timer).
  • Scaled icon caching via AssetManager.

4. Process Lifecycle & Clean Shutdown

• Target: 0 orphan / zombie processes after window close.
• Verification: 10/10 automated launch & destroy cycles completed with zero zombie processes.
• Mechanism:
  • Central _on_close coordinator canceling background workers and timers before Tk destruction.
  • LifecycleSupervisor tracking child processes by UUID and PID lease.