Will snapshot save backup.db commit *.wal to backup.db?

[njuptlzf]

Does snapshot save backup.db commit the *.wal files to backup.db, forming a complete database file so that complete data can be restored when snapshot restore backup.db is executed?

[aniketatgithub]

No, snapshot save does not copy the member's .wal files into backup.db.

What it saves is a backend database snapshot from the member. That file contains the committed key-value state at the snapshot revision, so snapshot restore can restore from backup.db without also copying the source member's WAL files.

During restore, etcd writes that database into a new data directory and creates fresh WAL and snapshot metadata there. So for this restore path, you do not need a separate copy of the old WAL files.

The snapshot only covers the state at the snapshot point. Writes after the snapshot are not included.