feat(experiments): E4 vs E1 results + p99 attribution figures

Browse Source

Headline: KVC v2 + load-floor + RDMA beats naive PD-disagg on
mean/p50/p90 by 30-65% (TTFT p50 31s vs 88s, lat p50 37s vs 93s,
wall-clock 64 min vs 88 min). Loses p99 by ~8% (TTFT 224 vs 207).

Wrote 4 figures (docs/figures/):
  e1_vs_e4_ttft_pdf.png         — bimodal E4 fast-path peak vs E1 single peak
  e1_vs_e4_latency_cdf.png      — CDF + log-survival showing tail crossover
  e4_path_latency.png           — per-execution-mode latency breakdown
  e1_vs_e4_p99_attribution.png  — what makes up E4's p99 tail

P99 tail attribution (this is the key finding):
  E4 p99 tail (n=65, TTFT ≥ 179.9s):
    fast-path direct-to-d        0 % (0/65)
    reseed paths                 5 % (3/65)
    fallback paths              88 % (57/65)
      large-append-session-cap  43 %  ← biggest culprit
      no-d-capacity             17 %
      large-append              14 %

Implication: D→P snapshot (designed to optimize reseed slow path)
even if fully working would touch ≤5% of the p99 tail. The real
bottleneck is *fallback chain* (admission retry + seeded-router
cold start), not reseed. Optimizing p99 needs work on fallback,
not more D→P plumbing.

Full analysis: docs/E4_VS_E1_RESULTS_ZH.md

...

This commit is contained in:

Claude Code Agent

2026-05-13 12:23:11 +08:00

parent af966f2371

commit e9ad1c4bc7

6 changed files with 549 additions and 0 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download Patch File Download Diff File Expand all files Collapse all files

BIN

docs/figures/e1_vs_e4_latency_cdf.png Normal file

Binary file not shown.

Side by Side After Width:  |  Height:  |  Size: 222 KiB

BIN

docs/figures/e1_vs_e4_p99_attribution.png Normal file

Binary file not shown.

Side by Side After Width:  |  Height:  |  Size: 257 KiB

BIN

docs/figures/e1_vs_e4_ttft_pdf.png Normal file

Binary file not shown.

Side by Side After Width:  |  Height:  |  Size: 282 KiB

BIN

docs/figures/e4_path_latency.png Normal file

Binary file not shown.

Side by Side After Width:  |  Height:  |  Size: 158 KiB