Sentry: 429 rate limited, events dropped

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Sentry: 429 rate limited, events dropped

The error

SDK debug output or server logs show 429 responses from the ingest endpoint. Events are being dropped before they become issues.

Which limiter is it

• Quota exhausted: you hit the monthly limit for that data category (errors, spans, replays, attachments, logs, metrics each have their own). Everything over the line is refused until the quota resets or is raised.
• Spike protection: volume spiked above your baseline-derived threshold, and Sentry started dropping the excess so you are not billed for the anomaly. This is per-project and must be enabled in Settings > Spike Protection (Billing or Owner role).

Check Settings > Subscription > Usage (the Stats Usage tab shows per-project breakdowns) to see which project and which category spiked, and when.

Fix order, cheapest first

1. Confirm spike protection is on for every project. It is the cheapest insurance and the docs list it first.
2. Find the burner: the Usage tab shows which project and category. A single noisy deploy or a retry storm is the usual story.
3. Cut at the source: lower tracesSampleRate, add ignoreErrors/beforeSend filters, fix the bug causing the spike.
4. Adjust quota or add pay-as-you-go only after the source is controlled, or you are just funding the noise.

Verify

After the fix, watch the Usage tab for the category to fall back under the threshold line, and confirm 429s stop in SDK debug output. If drops continue with normal volume, the quota itself is undersized for the traffic.

Researched against live Sentry docs 2026-09-26. The quotas page (docs.sentry.io/pricing/quotas/) documents: spike protection uses baseline consumption to compute a threshold and drops excess events so you are not charged for the spike; it is enabled per project by Billing/Owner roles via Settings > Spike Protection; events and attachments exceeding quota are not accepted; the page lists quota-management actions ordered easiest-first (spike protection, adjust quota, rate limit, review repeated events, filter events, update sample rate, SDK filtering); and the Usage tab of Stats shows per-project consumption.