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fix: stale KV fallback + never cache null on /perps cohort fetch #1687

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Merged
Flotapponnier merged 2 commits into from
Jul 29, 2026
Merged

fix: stale KV fallback + never cache null on /perps cohort fetch #1687

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d316fd2
fix: merge region+chain pills into one flex row, no labels
Flotapponnier Jul 29, 2026
d10b30d
fix: stale KV fallback + never cache null on /perps cohort fetch
Flotapponnier Jul 29, 2026
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102 changes: 39 additions & 63 deletions src/components/data-api-bench-groups.tsx
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Original file line number Diff line number Diff line change
Expand Up @@ -165,19 +165,9 @@ function BenchRow({
{/* Region / chain breakdown */}
<td className="pl-3 pr-5 py-3.5 align-top hidden lg:table-cell">
{showRegionChain ? (
<div className="flex flex-col gap-2">
{hasRegions && (
<div className="flex flex-col gap-1">
<span className="label-mono text-[8px] text-ink-faint uppercase tracking-wider" style={{ fontFamily: "var(--font-mono, monospace)" }}>Region</span>
<RegionStrip leaders={bench.regionLeaders} unit={bench.unit} />
</div>
)}
{hasChains && (
<div className="flex flex-col gap-1">
<span className="label-mono text-[8px] text-ink-faint uppercase tracking-wider" style={{ fontFamily: "var(--font-mono, monospace)" }}>Chain</span>
<ChainStrip leaders={bench.chainLeaders} unit={bench.unit} />
</div>
)}
<div className="flex flex-wrap gap-1.5">
{hasRegions && <RegionStrip leaders={bench.regionLeaders} unit={bench.unit} />}
{hasChains && <ChainStrip leaders={bench.chainLeaders} unit={bench.unit} />}
</div>
) : (
<span className="text-ink-faint text-[11px]">global</span>
Expand All @@ -200,7 +190,7 @@ function RegionStrip({
);

return (
<div className="flex flex-wrap gap-1.5">
<>
{sorted.map((l) => (
<Link
key={l.region}
Expand All @@ -226,7 +216,7 @@ function RegionStrip({
</span>
</Link>
))}
</div>
</>
);
}

Expand All @@ -240,14 +230,14 @@ function ChainStrip({
const uniqueWinners = new Set(leaders.map((l) => l.providerSlug)).size;
const isSpecialist = uniqueWinners === leaders.length && leaders.length > 3;

if (isSpecialist) {
// Each chain has its own specialist — compact icon-only chips
const MAX = 5;
const visible = leaders.slice(0, MAX);
const overflow = leaders.length - MAX;
return (
<div className="flex flex-wrap gap-1 items-center">
{visible.map((l) => (
const MAX = isSpecialist ? 5 : 3;
const visible = leaders.slice(0, MAX);
const overflow = leaders.length - MAX;

return (
<>
{visible.map((l) =>
isSpecialist ? (
<Link
key={l.chain}
href={`/products/${l.providerSlug}`}
Expand All @@ -262,50 +252,36 @@ function ChainStrip({
</span>
<ProviderLogo slug={l.providerSlug} name={l.providerName} size={10} />
</Link>
))}
{overflow > 0 && (
<span className="text-[9px] text-ink-faint">+{overflow}</span>
)}
</div>
);
}

// Some provider dominates multiple chains — full pills capped at 3
const MAX = 3;
const visible = leaders.slice(0, MAX);
const overflow = leaders.length - MAX;

return (
<div className="flex flex-wrap gap-1.5 items-center">
{visible.map((l) => (
<Link
key={l.chain}
href={`/products/${l.providerSlug}`}
className="flex items-center gap-1 rounded-md border border-ink/8 bg-paper-soft/60 px-2 py-1 hover:border-ink/20 hover:bg-paper-soft transition-colors"
title={`${l.label}: ${l.providerName} — ${fmtDataValue(l.p50, unit)}`}
>
<span
className="label-mono text-[9px] text-ink-faint uppercase tracking-wide"
style={{ fontFamily: "var(--font-mono, monospace)" }}
>
{l.label}
</span>
<ProviderLogo slug={l.providerSlug} name={l.providerName} size={12} />
<span className="text-[10.5px] text-ink-soft font-medium">
{l.providerName.split(" ")[0]}
</span>
<span
className="label-mono text-[10px] text-ink-faint"
style={{ fontFamily: "var(--font-mono, monospace)" }}
) : (
<Link
key={l.chain}
href={`/products/${l.providerSlug}`}
className="flex items-center gap-1 rounded-md border border-ink/8 bg-paper-soft/60 px-2 py-1 hover:border-ink/20 hover:bg-paper-soft transition-colors"
title={`${l.label}: ${l.providerName} — ${fmtDataValue(l.p50, unit)}`}
>
{fmtDataValue(l.p50, unit)}
</span>
</Link>
))}
<span
className="label-mono text-[9px] text-ink-faint uppercase tracking-wide"
style={{ fontFamily: "var(--font-mono, monospace)" }}
>
{l.label}
</span>
<ProviderLogo slug={l.providerSlug} name={l.providerName} size={12} />
<span className="text-[10.5px] text-ink-soft font-medium">
{l.providerName.split(" ")[0]}
</span>
<span
className="label-mono text-[10px] text-ink-faint"
style={{ fontFamily: "var(--font-mono, monospace)" }}
>
{fmtDataValue(l.p50, unit)}
</span>
</Link>
)
)}
{overflow > 0 && (
<span className="text-[10px] text-ink-faint">+{overflow}</span>
)}
</div>
</>
);
}

Expand Down
57 changes: 49 additions & 8 deletions src/lib/perp-stats.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -314,12 +314,13 @@ async function fetchPerpCohortRaw(): Promise<PerpCohortSummary | null> {
const snapshot = await readCohortSnapshot<PerpCohortSummary>(
PERP_COHORT_KEY,
);
// Only use the snapshot if it was written within the last 2 minutes.
// Without this check, the 24h KV TTL means stale Prometheus data is
// served indefinitely even though the harness publishes every minute.
// Fresh snapshot (written within the last 2 min) is the fast path.
if (snapshot && snapshot.ageMs < 2 * 60 * 1000) {
return snapshot.data;
}
// Snapshot stale or missing — try live Prom. On Vercel, promUrl()
// returns null (VPS Prom is not publicly exposed), so this only
// succeeds from the worker process.
const fresh = await fetchPerpCohortFresh();
if (fresh) {
try {
Expand All @@ -331,18 +332,41 @@ async function fetchPerpCohortRaw(): Promise<PerpCohortSummary | null> {
}`,
);
}
return fresh;
}
return fresh;
// Both paths failed. Serve the stale snapshot as a last resort so a
// brief worker hiccup or Vercel cache-miss race doesn't blank the
// page. Cap at 10 min: beyond that we surface "unavailable" so a
// sustained worker outage is still visible.
if (snapshot && snapshot.ageMs < 10 * 60 * 1000) {
console.warn(
`perp-cohort: serving stale snapshot (${Math.round(snapshot.ageMs / 1000)}s old)`,
);
return snapshot.data;
}
return null;
}

const fetchPerpCohortCached = unstable_cache(
fetchPerpCohortRaw,
async () => {
const data = await fetchPerpCohortRaw();
// Throw on null so unstable_cache does not store a cached null —
// a single worker hiccup would otherwise blank the page for the
// full 60 s revalidate window. The public wrapper catches and
// returns null so the page still renders its fallback banner.
if (data === null) throw new Error("perp-cohort-unavailable");
return data;
},
["perp-cohort-v1"],
{ revalidate: 60, tags: ["perp-cohort"] },
);

export async function fetchPerpCohort(): Promise<PerpCohortSummary | null> {
return fetchPerpCohortCached();
try {
return await fetchPerpCohortCached();
} catch {
return null;
}
}

/**
Expand Down Expand Up @@ -453,18 +477,35 @@ async function fetchPerpByAssetMatrixRaw(): Promise<PerpAssetRow[]> {
}`,
);
}
return fresh;
}
// Prom failed — serve stale snapshot up to 10 min rather than empty.
if (snapshot && snapshot.ageMs < 10 * 60 * 1000 && Array.isArray(snapshot.data) && snapshot.data.length > 0) {
console.warn(
`perp-by-asset: serving stale snapshot (${Math.round(snapshot.ageMs / 1000)}s old)`,
);
return snapshot.data;
}
return fresh;
}

const fetchPerpByAssetMatrixCached = unstable_cache(
fetchPerpByAssetMatrixRaw,
async () => {
const data = await fetchPerpByAssetMatrixRaw();
// Don't cache an empty result — same rationale as perp-cohort above.
if (data.length === 0) throw new Error("perp-by-asset-unavailable");
return data;
},
["perp-by-asset-matrix-v2"],
{ revalidate: 120, tags: ["perp-by-asset"] },
);

export async function fetchPerpByAssetMatrix(): Promise<PerpAssetRow[]> {
return fetchPerpByAssetMatrixCached();
try {
return await fetchPerpByAssetMatrixCached();
} catch {
return [];
}
}

/**
Expand Down
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