We saw a case where the recovery stats reported `recovered_bytes` greater than `length_in_bytes` for one file:

```
GET /_recovery?detailed

200 OK
...
{
  "name": "_buk.fdt",
  "length_in_bytes": 26891307173,
  "reused": false,
  "recovered_in_bytes": 35324928266,
  "recovered_from_snapshot_in_bytes": 8433621093
}
...
```

NB `35324928266 == 26891307173 + 8433621093`

This causes Elasticsearch to compute a negative value for the reserved space on the target node of this recovery, which prevents stats APIs from working. This appears to be caused by a network-level failure which triggers a retry without first cancelling an ongoing download of a different file with the same name from the snapshot repository.

---

### Workaround

Restart the target node to clear these stats.
server/src/main/java/org/elasticsearch/indices/recovery/RecoveryState.java
return "file (name ["
                + name
                + "], reused ["
                + reused
                + "], length ["
                + length
                + "], "
                + "recovered ["
                + recovered
                + "], recovered from snapshot ["
                + recoveredFromSnapshot
                + "]) ";
        }
    }
    public static class RecoveryFilesDetails implements ToXContentFragment, Writeable {
        protected final Map<String, FileDetail> fileDetails;
        protected boolean complete;
        public RecoveryFilesDetails() {
            fileDetails = new HashMap<>();
        }
        RecoveryFilesDetails(StreamInput in) throws IOException {
            fileDetails = in.readMapValues(FileDetail::new, FileDetail::name);
            if (in.getVersion().onOrAfter(StoreStats.RESERVED_BYTES_VERSION)) {
                complete = in.readBoolean();
            } else {
                
                
                
                
                complete = fileDetails.isEmpty() == false;