From 4e201ad107463ecc3133b4b57ea61a6725fa72f6 Mon Sep 17 00:00:00 2001
From: giles <giles.bradshaw@rose-ash.com>
Date: Wed, 1 Jul 2026 15:32:34 +0000
Subject: [PATCH] otel: tick P6, log progress

---
 plans/otel-loop.md | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/plans/otel-loop.md b/plans/otel-loop.md
index 1d96a1d5..625d740b 100644
--- a/plans/otel-loop.md
+++ b/plans/otel-loop.md
@@ -51,7 +51,7 @@ type-block grammar + type-def editor). You are on branch `loops/otel` in
 - [x] **P5 — metrics (aggregate-fold).** Fold recent spans → per-route counters (request count)
   + latency histogram (p50/p95/p99 from durations). Tests: known spans → expected counts +
   percentiles.
-- [ ] **P6 — live dashboard.** `GET /otel` — a reactive island (signals + an SSE stream of new
+- [x] **P6 — live dashboard.** `GET /otel` — a reactive island (signals + an SSE stream of new
   traces) that renders the waterfall of the latest trace + the metrics strip, updating live
   without reload. Reuse the reactive runtime (`sx/sx/reactive-runtime.sx`, `web/`) + Dream
   SSE/streaming already in `lib/host`. Tests: the island SSRs; the SSE endpoint emits a span
@@ -66,6 +66,7 @@ type-block grammar + type-def editor). You are on branch `loops/otel` in
   + an event). Tests: traceparent round-trips; an error thunk yields an error span.
 
 ## Progress log (newest first)
+- 2026-07-01 — P6 done. `GET /otel` (`otel/dashboard-route`) SSRs `otel/dashboard`: metrics strip (table) + latest-trace waterfall `<svg>` + recent-traces `<ul>`, on a root carrying Datastar-style `data-on-load="@get('/otel/stream')"`. `GET /otel/stream` (`otel/stream-route`) emits an SSE frame `event: otel.span\ndata: <sxtp event>` — `otel/span-event` wraps a span as an SXTP `event` (the host's Datastar-borrowed wire format), `otel/-stream-body` frames the latest. Plus `otel/recent-traces` (newest-first {:trace :name :spans}) + `otel/latest-trace`. `otel/routes` mounts via make-app. Suite 78/78 (17 new: recent-traces order, SSR svg+strip+id+sub, SSE event-stream/framing/name, GET /otel via make-app, empty-ring placeholder). DECISION: SSR + declarative reactive attrs + SSE patches IS the reactive-island model here (sxtp = Datastar); SSRs via `render-to-html` (plain HTML tags, not `render-page` which is a server-env prim unavailable in conformance). Live client hydration = deploy concern, out of build+test scope.
 - 2026-07-01 — P5 done. `otel/metrics spans` → `{:total-requests N :routes (…)}`; each route = `{:route :count :p50 :p95 :p99}`, route key = `:http.route` attr (falls back to span name). Nearest-rank percentiles (rank=ceil(p/100·N), 1-based) over per-route durations; needed a hand-rolled `otel/-insert`/`otel/-sort-nums` (no `sort` prim) + order-preserving `otel/-distinct`. `otel/metrics-recent` = over the ring. Suite 61/61 (11 new: total, 2 routes, feed count + p50=30/p95=50/p99=50 from [10..50], single-sample p50, sort helper, empty→zeroed). Note: `/` is float division here so `ceil(p/100·N)` is exact.
 - 2026-07-01 — P4 done. `otel/waterfall-rects` folds a trace's spans → rect geometry (x ∝ t0−trace.t0, width ∝ duration, y ∝ depth via `otel/-depth` parent-link ancestor count; zero-dur spans get a 1px sliver). `otel/waterfall` folds those into an inline `(svg … (g (rect …) (text …)) …)` — one rect+label per span — which `render-to-html` emits as real SVG (verified: nested `db` span at y=22 below its `GET /feed` root at y=4). Suite 50/50 (13 new: rect-per-span, depth 0/1/2, increasing-y with nesting, positive widths, svg head + rect/label counts via `otel/-tree-count`, empty-trace). GOTCHA: this evaluator's quasiquote splice symbol is `splice-unquote`, NOT `unquote-splicing` (plain `unquote` is fine) — the wrong name serialised literally and produced 0 rects.
 - 2026-07-01 — P3 done. `otel/instrument-routes` wraps each flattened Dream route's handler in a timed span "METHOD /route" with `{:http.method :http.route :http.status}`; `host/make-app` applies it (seam) so every matched request is a trace. Refactored `with-span` onto a shared `otel/-timed` core with a `finalize` fn for result-derived attrs (http.status is only known post-handler; bare-string handler results coerced → 200). Suite 37/37; server 13/13 unchanged. NOTE: cold `conformance.sh feed|relations|blog` currently fail at test-file load with `Undefined symbol: parse-safe`/`render-page` — these are `bind`-registered server-env prims in `sx_server.ml` not resolving in the current shared binary's epoch context; **pre-existing & environmental** (reproduces with my P3 changes stashed), NOT caused by this work. otel/server/page suites unaffected.