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
"Trying to set a routing entry with a different allocation. Current " + currentRouting + ", new " + newRouting
                );
            }
            if (currentRouting.primary() && newRouting.primary() == false) {
                throw new IllegalArgumentException(
                    "illegal state: trying to move shard from primary mode to replica mode. Current "
                        + currentRouting
                        + ", new "
                        + newRouting
                );
            }
            if (newRouting.primary()) {
                replicationTracker.updateFromMaster(applyingClusterStateVersion, inSyncAllocationIds, routingTable);
            }
            if (state == IndexShardState.POST_RECOVERY && newRouting.active()) {
                assert currentRouting.active() == false : "we are in POST_RECOVERY, but our shard routing is active " + currentRouting;
                assert currentRouting.isRelocationTarget() == false
                    || currentRouting.primary() == false
                    || replicationTracker.isPrimaryMode()
                    : "a primary relocation is completed by the master, but primary mode is not active " + currentRouting;
                changeState(IndexShardState.STARTED, "global state is [" + newRouting.state() + "]");
            } else if (currentRouting.primary()
                && currentRouting.relocating()
                && replicationTracker.isRelocated()
                && (newRouting.relocating() == false || newRouting.equalsIgnoringMetadata(currentRouting) == false)) {
                    
                    
                    
                    throw new IndexShardRelocatedException(
                        shardId(),