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/index/shard/IndexShard.java
}
                                    }
                                }
                            });
                        } catch (final AlreadyClosedException e) {
                            
                        }
                    }, null);
                }
            }
            
            this.shardRouting = newRouting;
            assert this.shardRouting.primary() == false || this.shardRouting.started() == false || 
                                                                                                   
                this.indexShardOperationPermits.isBlocked() || 
                this.replicationTracker.isPrimaryMode()
                : "a started primary with non-pending operation term must be in primary mode " + this.shardRouting;
            shardStateUpdated.countDown();
        }
        if (currentRouting.active() == false && newRouting.active()) {
            indexEventListener.afterIndexShardStarted(this);
        }
        if (newRouting.equals(currentRouting) == false) {
            indexEventListener.shardRoutingChanged(this, currentRouting, newRouting);
        }
        if (indexSettings.isSoftDeleteEnabled() && useRetentionLeasesInPeerRecovery == false) {
            final RetentionLeases retentionLeases = replicationTracker.getRetentionLeases();
            final Set<ShardRouting> shardRoutings = Sets.newHashSetWithExpectedSize(routingTable.size());
            for (int copy = 0; copy < routingTable.size(); copy++) {