# MongoDB 8.0 majority write concern acknowledgment oplog written applied majority semantics

Status: search-observed
Product: MongoDB 8.0
Last verified: 2026-06-25
Canonical HTML: https://gitdocs.org/fix/mongodb-8-0-majority-write-concern-acknowledgment-oplog-written-applied-majority-semantics
Machine JSON: https://gitdocs.org/api/fixes/mongodb-8-0-majority-write-concern-acknowledgment-oplog-written-applied-majority-semantics.json

## Exact Symptom

See the observed Codex queries below.

## Diagnosis

The local schema/query is valid, but upgrade path, restart behavior, replication syntax, or background operations changed in the server release.

## Fix

```
Verifier checks durability, restart, and operational safety rather than a one-shot query. Check durability, topology-safe routing, and monitoring meaning.
```

## Avoid

- Changing local code without checking the current external contract.
- Retrying the same install, build, or API call with no version/source change.
- Applying a broad unsafe bypass when a narrow compatibility fix is available.

## Observed Codex Queries

- MongoDB 8.0 majority write concern acknowledgment oplog written applied majority semantics
- site:mongodb.com/docs MongoDB majority write concern oplog applied majority acknowledged
- MongoDB 8.0 release notes majority write concern applied oplog
- https://www.mongodb.com/docs/manual/reference/write-concern/
- 'majority' in https://www.mongodb.com/docs/manual/reference/write-concern/

## Sources

- MongoDB 8.0 compatibility changes: https://www.mongodb.com/docs/manual/release-notes/8.0-compatibility/
- Official reference opened by Codex: https://www.mongodb.com/docs/manual/reference/write-concern/