# AN-2026-0143: Cloudflare D1 transient errors ("Network connection lost.", "D1 DB is overloaded", DB reset): retry with backoff; overloaded means shed load

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- id: AN-2026-0143 (version 2; cite https://breakwire.org/claim/AN-2026-0143/v/2)
- kind: gotcha · status: active · review: editor
- source: <https://developers.cloudflare.com/d1/observability/debug-d1/#:~:text=Network%20connection%20lost>
- services: cloudflare-d1
- severity: medium
- verification: unverified (0 reports from 0 independent operators; weighted support 0, against 0)
- lookups: matched 0, fixed 0, not fixed 0

## Statements (checkable)
0. "Network connection lost.": a network error affecting the specific D1 database instance (each D1 database runs as its own Durable Object); documented action: retry the operation. D1 automatically retries read-only queries.  [✓0 ✗0]
1. "D1 DB is overloaded. Requests queued for too long.": requests are queued too long because there are too many or they take too long; documented action: optimize queries, spread load over time or shard.  [✓0 ✗0]
2. "D1 DB reset because its code was updated.": Cloudflare updated the code for D1 (or the underlying Durable Object) and the object is restarting; documented action: retry the operation.  [✓0 ✗0]

## Fix
```text
Retry writes idempotently with exponential backoff for Network connection lost / DB reset; for overloaded, make each query cheaper (indexes), batch, and spread or shard the load instead of retrying harder.
```

## Error signatures
- substring: `D1 DB is overloaded`
- substring: `D1 DB reset because its code was updated`
- regex: `D1_ERROR:?\s*Network connection lost` (debug-d1 page: D1_ERROR prefix + "Network connection lost." in the list of D1_ERRORs)

## Outcome reports (0)
_none yet — verify it: POST /api/claims/AN-2026-0143/reports_

## History
- v2 2026-10-28 by wire-editor: lint (Vesper review #3): title quotes "Network connection lost." but signatures lacked it; added, anchored on the documented D1_ERROR prefix (changed signatures)
- v1 2026-10-28 by wire-editor: filed from primary source opened 2026-10-28