TK-11793: scan budget 150s + stale-while-revalidate scan (fleet scanner is ~90s at 59 sessions); honest stale flag when the last scan is old or was the fallback

6b98c039ad3994ff1c0689dbdbe9658d2843fac3 · 2026-09-16 09:19:53 -0700 · Steve Abrams

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

Files touched

M lib/queue.js

Diff

commit 6b98c039ad3994ff1c0689dbdbe9658d2843fac3
Author: Steve Abrams <steve@designerwallcoverings.com>
Date:   Wed Sep 16 09:19:53 2026 -0700

    TK-11793: scan budget 150s + stale-while-revalidate scan (fleet scanner is ~90s at 59 sessions); honest stale flag when the last scan is old or was the fallback
    
    Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
---
 lib/queue.js | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/lib/queue.js b/lib/queue.js
index 0982b12..eac370b 100644
--- a/lib/queue.js
+++ b/lib/queue.js
@@ -20,8 +20,13 @@ const ticketlane = require('./ticketlane');
 const HOME = process.env.HOME || require('os').homedir();
 const TS_PY = path.join(HOME, 'Projects/terminal-status/terminal_status.py');
 const ALL_SH = path.join(HOME, '.claude/skills/allcolordots/allcolordots.sh');
-const CACHE_MS = 4000;
-const SCAN_TIMEOUT_MS = 45000;
+// 2026-09-16: at 59 live sessions the dot scanner takes ~90s (iTerm2 itself at 150% CPU), so a
+// 45s budget made it fail → allcolordots fallback → stale → WARN. Budget it for reality and let
+// the last good scan serve requests while a fresh one runs in the background (never a fake PASS:
+// stale:true is still surfaced when the LAST scan was the fallback or older than STALE_AFTER_MS).
+const CACHE_MS = 15000;
+const SCAN_TIMEOUT_MS = 150000;
+const STALE_AFTER_MS = 5 * 60 * 1000;
 
 // copied from terminal_status.py:48-63
 const COLORS = {
@@ -88,6 +93,12 @@ async function rawScan() {
 
 async function scan() {
   if (cached && Date.now() - cached.ts < CACHE_MS) return cached.result;
+  // Stale-while-revalidate for the SCAN too: if a scan is running and we have a previous one,
+  // serve it (flagged stale when it is genuinely old) instead of waiting ~90s.
+  if (inflight && cached) {
+    const age = Date.now() - cached.ts;
+    return { ...cached.result, stale: !!cached.result.stale || age > STALE_AFTER_MS, scanAgeMs: age, refreshing: true };
+  }
   if (inflight) return inflight;
   inflight = rawScan().then((res) => {
     cached = { ts: Date.now(), result: res };

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