27-EFT.WP.Packets.Light v1.0 | Chapter 14 — Runtime & Streaming (Caching / Fallback / Panels)

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Chapter 14 — Runtime & Streaming (Caching / Fallback / Panels)

One-sentence goal: Build a streaming-runtime convention for optical-packet links on an execution graph G = (V, E) centered on windows / caching / fallback / panels, ensuring dual-form compliance (configured vs measured) and dimensional correctness, with runtime evidence published via a manifest.

I. Scope & Objects

1. Inputs
   • Framing & timebase: frame_spec = { T_epoch, T_f, T_slot, T_sym, T_guard } (Ch. 3), monotone settlement clock tau_mono and publication instant ts.
   • Runtime configuration: window width/stride W / H, allowed lateness lateness, watermark policy watermark, cache policy cache.policy (ttl / size / key), rate-limit / backpressure policies.
   • Upstream manifests: artifacts from physics / compensation / metrology / harmonization—manifest.packet.{ phys, comp, meas, tarr, swrt, … }.
2. Outputs
   • Online products: windowed metrics and arrival time T_arr*, metrology (OSNR / EVM / BER), switching/queueing delays lat_*, and the online dual-form error delta_form_rt;
   • Runtime panels & alerts: panel.* (SLI/SLO curves, quantiles/heatmaps), fallback traces;
   • Runtime manifest: manifest.packet.rt.* (defined in this chapter).
3. Boundary
   Physics & compensation: Chs. 2 / 6; switching & queueing: Chs. 9 / 10. This chapter focuses on execution graph / caching / fallback / panels.

II. Terms & Variables

• Windows & lateness: win_k = [ t_k, t_k + W ), hop H, overlap O = 1 − H/W, allowed lateness lateness; watermark function wm(t).
• Cache: key K_cache = hash( frame.hash, path.hash, label, RefCond, algo.hash, win_id ); hit rate hit; staleness stale_ratio.
• Rate-limit & backpressure: input rate λ_in, service rate μ, queue depth q, drop rate drop_rate; token bucket ( r, B ).
• Dual forms (runtime): configured (model/manifest expected values, e.g., lat_total^{config}, T_arr^{config}) vs measured (windowed timestamps / metrology), discrepancy delta_form_rt.
• Panels & resources: latency_p{q}, cpu_pct, mem_pct, gpu_util, err_rate, coverage.
• Dimensions: unit(W, H, lateness, latency) = "[T]", unit(hit, stale_ratio, drop_rate, coverage) = 1.

III. Postulates P614-*

• P614-1 (Two forms in parallel): For each window win_k, compute and publish metric^{config} and metric^{meas}, recording delta_form_rt = | metric^{config} − metric^{meas} |.
• P614-2 (Temporal semantics & window close): A window closes if wm(t_proc) ≥ t_k + W − lateness; late data triggers patch recompute or a shadow pipeline—policy must be persisted.
• P614-3 (Traceable cache): Cache keys include algorithm and RefCond; any hash change invalidates and recomputes.
• P614-4 (Dimensional compliance): Run check_dim( y − f(x) ) before publication; log any log↔linear conversions in manifest.packet.rt.*.
• P614-5 (Fail-Closed fallback): On SLO/contract or dual-form assertion failure, degrade / bypass / rollback to the last signed version and persist the strategy card.
• P614-6 (Privacy & minimum visibility): Runtime manifests contain no raw sensitive data—only hashes/pointers/statistics/signatures.

IV. Minimal Equations S614-*

1. Window fusion & publication
   • Weighted fusion (example: online arrival-time harmonization):
     T_arr*,win = w_cnt t̂_cnt + w_cont t̂_cont + w_phys T_form2, with weights w_* ∝ 1 / u_*^2 (uncertainties from the most recent window).
   • Published quantiles:
     z_{p95} = quantile( { z_i | i ∈ win_k }, 0.95 ).
2. Online dual-form error
   delta_form_rt(metric) = | metric^{config}(win_k) − metric^{meas}(win_k) |, for metric ∈ { T_arr, OSNR, EVM, lat_total, P_block, P_cont }.
3. Cache & staleness
   • Che approximation (hit): find T_c s.t. ∑_u ( 1 − e^{−λ_u T_c} ) = cache.size; then hit_u ≈ 1 − e^{−λ_u T_c},
     hit = ( ∑ λ_u hit_u ) / ( ∑ λ_u ).
   • Staleness: stale_ratio = | items_expired_but_used | / | items_used |; must satisfy ≤ tol_stale.
4. Rate-limit / backpressure
   • Token bucket: generation r, bucket B; instantaneous burst ≤ B, long-term average ≤ r; choose r = ρ • μ (ρ < 1).
   • Stability: E[λ_in] < E[μ]; queue recursion q_{k+1} = max( 0, q_k + a_k − s_k ).
5. SLO breakdown
   • End-to-end delay: lat_total = lat_prop + lat_ser + lat_sw + lat_q + lat_proc (per Ch. 10);
   • Target: p95(lat_total) ≤ SLO.latency_p95, drop_rate ≤ SLO.drop_max.
6. Fallback ladder (expression)
   mode := scale_down → damping → lower_order → bypass → rollback_version, each step persisting actions[] and outcome metrics.

V. Metrology Pipeline M60-14 (Ready → Execute → Verify → Fallback → Persist)

1. Ready: freeze frame_spec, RefCond, W/H/lateness/watermark, cache.policy, and SLO/contract thresholds; load upstream manifests and algorithm signatures.
2. Execute: advance windows by H; look up K_cache; on miss, compute; log latency, cpu/mem/gpu, hit, stale_ratio, watermark_lag.
3. Verify:
   • Dual-form errors delta_form_rt;
   • SLO/contracts: latency_p95 / drop_rate / hit / stale_ratio and ρ / queue depth;
   • Dimensional & mask/band consistency (aligned with Chs. 4 / 11).
4. Fallback: when any key assertion fails, execute strategy cards per S614-6; persist actions, blast radius, and recovery.
5. Persist:
   manifest.packet.rt.* = { frame.hash, path.hash, algo.hash, RefCond, W, H, lateness, watermark, cache:{ ttl, size, policy, hit, stale_ratio }, metrics:{ delta_form_rt, latency_p{50,95,99}, drop_rate, ρ, watermark_lag }, resources:{ cpu_pct, mem_pct, gpu_util }, actions[], contracts.*, signature }.

VI. Contracts & Assertions C60-14x (Suggested Thresholds)

• C60-1401 (Dual-form gap): delta_form_rt_p95 ≤ tol_rt (business-specific).
• C60-1402 (Latency / jitter): latency_p95 ≤ SLO.latency_p95, jitter_p95 ≤ 0.2 • W.
• C60-1403 (Cache efficacy): hit ≥ hit_min (typ. ≥ 0.8), stale_ratio ≤ tol_stale.
• C60-1404 (Backpressure stability): E[λ_in] < E[μ] and drop_rate ≤ drop_max.
• C60-1405 (Panel freshness): panel.update_interval ≤ Δt_panel_max, coverage ≥ cov_min.
• C60-1406 (Dimensional compliance): time / rate / probability fields pass check_dim; dB↔linear conversions recorded.

VII. Implementation Bindings I60-14* (interfaces, I/O, invariants)

• I60-141 plan_stream_windows(W, H, lateness, watermark) -> schedule
• I60-142 query_or_compute(cache, K_cache, fn) -> { value, hit, stale }
• I60-143 enforce_rate(token_bucket:{ r, B }, now) -> { permit, state }
• I60-144 measure_runtime(stream) -> { latency, drop_rate, ρ, cpu_pct, mem_pct, gpu_util, watermark_lag }
• I60-145 compare_dual_runtime(cfg_metrics, meas_metrics) -> delta_form_rt
• I60-146 apply_fallback(mode, ctx) -> actions[]
• I60-147 snapshot_panel(metrics, resources, u/U) -> { panel.uri, snapshot.hash }
• I60-148 emit_runtime_manifest(results, policy) -> manifest.packet.rt
  Invariants: two_forms_present = true; schedule is monotone; cache keys include algorithm/convention and RefCond; every fallback is replayable and auditable.

VIII. Cross-References

• Framing & conservation: Chapter 3.
• Physics / compensation / metrology: Chs. 2 / 6 / 11.
• Arrival-time harmonization: Chapter 8.
• Switching / queueing: Chs. 9 / 10 (lat_*, resources & conservation).
• Security & integrity: Chapter 13 (alert linkage and mitigation).

IX. Quality & Risk Control

• SLI / SLO: delta_form_rt_p95, latency_p95, drop_rate, hit, stale_ratio, ρ_p95, watermark_lag_p95, panel_freshness.
• Fallback gradient: scale_down → damping → lower_order → bypass → rollback_version, coordinated with security/integrity policies (Ch. 13).
• Audit: window signatures & cache keys, SLO breaches and dual-form distributions, fallback actions & impact scope, and the manifest.packet.rt.* signature chain with replay consistency.

Summary

• This chapter establishes the streaming runtime baseline for optical packets: windowing, cache reuse, rate-limit/backpressure, fallback, and panels.
• Using P614 / S614 / M60-14 / C60-14x / I60-14* and manifest.packet.rt.*, runtime becomes traceable, auditable, and rollback-ready, interlocking with prior chapters’ conventions across physics / compensation / metrology / routing / queueing.