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 ± 0.0 |
| 1.0 ± 0.0 | 100.0 ± 0.0 | 1.5 ± 0.0 | 1.5 ± 0.0 | 1.9 ± 0.1 | 2.1 ± 0.1 |
| 1.9 ± 0.0 | 99.8 ± 0.1 | 2.9 ± 0.0 | 2.8 ± 0.0 | 3.4 ± 0.1 | 3.7 ± 0.1 |
| 4.3 ± 0.0 | 87.6 ± 0.2 | 6.3 ± 0.0 | 6.2 ± 0.0 | 6.8 ± 0.0 | 7.2 ± 0.0 |
| 5.7 ± 0.0 | 58.1 ± 0.2 | 8.3 ± 0.0 | 8.2 ± 0.0 | 8.7 ± 0.0 | 9.0 ± 0.0 |
| 6.6 ± 0.0 | 33.2 ± 0.2 | 9.5 ± 0.0 | 9.4 ± 0.0 | 9.9 ± 0.0 | 10.1 ± 0.0 |
| 7.4 ± 0.0 | 14.6 ± 0.1 | 10.5 ± 0.0 | 10.5 ± 0.0 | 10.9 ± 0.0 | 11.0 ± 0.0 |
| 7.8 ± 0.0 | 7.5 ± 0.0 | 11.1 ± 0.0 | 11.1 ± 0.0 | 11.4 ± 0.0 | 11.5 ± 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!