Commit Overhead vs Throughput
Commit Overhead vs Throughput
Analysis of commit protocol overhead as percentage of total transaction time.
Overhead = (commit_latency / total_latency) × 100
This represents time spent in retries, exponential backoff, and manifest I/O.
Values shown as mean ± standard deviation across seeds.
| Throughput (c/s) | Success Rate (%) | Mean Overhead (%) | P50 Overhead (%) | P95 Overhead (%) | P99 Overhead (%) |
|---|---|---|---|---|---|
| 0.2 ± 0.0 | 100.0 ± 0.0 | 0.4 ± 0.0 | 0.4 ± 0.0 | 0.6 ± 0.0 | 0.7 ± 0.0 |
| 0.5 ± 0.0 | 100.0 ± 0.0 | 0.8 ± 0.0 | 0.8 ± 0.0 | 1.1 ± 0.0 | 1.2 ± 0.1 |
| 1.0 ± 0.0 | 100.0 ± 0.0 | 1.5 ± 0.0 | 1.4 ± 0.0 | 1.8 ± 0.0 | 2.0 ± 0.0 |
| 2.0 ± 0.1 | 100.0 ± 0.0 | 2.8 ± 0.1 | 2.8 ± 0.1 | 3.3 ± 0.1 | 3.5 ± 0.1 |
| 5.0 ± 0.0 | 100.0 ± 0.0 | 7.0 ± 0.0 | 7.0 ± 0.0 | 7.6 ± 0.1 | 8.0 ± 0.1 |
| 9.7 ± 0.0 | 98.8 ± 0.1 | 13.6 ± 0.0 | 13.6 ± 0.1 | 14.4 ± 0.1 | 14.9 ± 0.1 |
| 15.1 ± 0.0 | 76.3 ± 0.3 | 21.1 ± 0.0 | 21.0 ± 0.0 | 21.6 ± 0.0 | 21.8 ± 0.0 |
| 17.6 ± 0.0 | 35.0 ± 0.1 | 24.5 ± 0.0 | 24.5 ± 0.0 | 24.9 ± 0.0 | 25.1 ± 0.0 |
| 18.6 ± 0.0 | 18.1 ± 0.1 | 25.9 ± 0.0 | 25.9 ± 0.0 | 26.3 ± 0.0 | 26.4 ± 0.0 |
Interpretation
- Low overhead (<10%): System operating efficiently, minimal contention
- Medium overhead (10-30%): Moderate contention, acceptable performance
- High overhead (30-50%): High contention, commit protocol becoming significant
- Very high overhead (>50%): Commit protocol dominates, system saturated
Values shown as mean ± standard deviation across multiple seeds. At saturation, overhead can exceed 50%, meaning more time is spent retrying commits than executing transactions!