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
if (file.reused() == false) {
                    total += file.length() - file.recovered();
                }
            }
            return total;
        }
        /**
         * percent of bytes recovered out of total files bytes *to be* recovered
         */
        public synchronized float recoveredBytesPercent() {
            long total = 0;
            long recovered = 0;
            for (FileDetail file : fileDetails.values()) {
                if (file.reused() == false) {
                    total += file.length();
                    recovered += file.recovered();
                }
            }
            if (total == 0 && fileDetails.size() == 0) {
                
                return 0.0f;
            }
            if (total == recovered) {
                return 100.0f;
            } else {
                return 100.0f * recovered / total;
            }
        }
        public synchronized int reusedFileCount() {
            int reused = 0;