Multi-Analyzer Heuristic Conflict Engine
Most bidirectional sync tools rely on a naive, binary rule: “newer timestamp wins”. In distributed cloud environments, this rule causes silent data loss because:
- Cloud storage APIs (e.g. Google Drive, Microsoft OneDrive, SharePoint) round timestamps to 1-second or 2-second windows or update them asynchronously.
- Device clocks can drift or suffer skew during daylight savings transitions.
- Rapid concurrent edits on mobile and desktop produce collisions where the “newer” file is actually an incomplete draft.
Bisync Hub replaces timestamp gambling with a multi-analyzer heuristic confidence engine.
The Evaluation Pipeline
When both Path1 and Path2 report modifications to the same file path, the engine executes four independent heuristic analyzers:
| Heuristic Analyzer | Signal Analyzed | Weight | Description |
|---|---|---|---|
| SizeDivergenceAnalyzer | Content volume delta | 30% | Detects dramatic file shrinks or expansions indicating truncation or major additions. |
| BinarySignatureAnalyzer | MIME & header magic bytes | 25% | Verifies format validity (e.g. SQLite database header, JPEG signatures) to penalize corrupt partial writes. |
| ClockSkewAnalyzer | Cross-remote timestamp drift | 25% | Evaluates cloud API timestamp granularity and compensates for known provider skews (e.g., OneDrive 2s window). |
| VelocityAnalyzer | Modification frequency | 20% | Scores edit frequency to distinguish steady active editing from stale background touches. |
Confidence Calculation & Safety Bands
The engine aggregates individual analyzer scores into a unified Confidence Index (0% - 100%):
Score >= 85% ──► [ HIGH CONFIDENCE ] ──► Auto-resolve in favor of dominant replica
60% - 84% ──► [ MEDIUM CONFIDENCE ]──► Backup losing candidate to .conflict-bak, then sync
Score < 60% ──► [ LOW CONFIDENCE ] ──► QUARANTINE: Halt file mutation & prompt Operator
Safety Features
- Deterministic Quarantine: Unresolvable collisions are safely preserved in a
.bisync_quarantine/isolation jail. - Conflict Backup Preserves: Even on high-confidence resolutions, the displaced version is moved to the backup store before overwriting.
- Clock Skew Tolerance: Built-in compensation algorithms for cloud timestamp drift and DST shifts.
All heuristic scoring weights and confidence thresholds are fully configurable in
bisync.envto match your organization’s risk tolerance.