```
CREATE TABLE default.x AS system.numbers ENGINE = Log;

INSERT INTO FUNCTION cluster('test_cluster_two_shards', default, x) SELECT * FROM numbers(10)

Received exception from server (version 20.11.1):
Code: 55. DB::Exception: Received from localhost:9000. DB::Exception: Method write is not supported by storage Distributed with more than one shard and no sharding key provided. 

0 rows in set. Elapsed: 0.001 sec. 

INSERT INTO FUNCTION cluster('test_cluster_two_shards', default, x, rand()) SELECT * FROM numbers(10)

Received exception from server (version 20.11.1):
Code: 42. DB::Exception: Received from localhost:9000. DB::Exception: Table function 'cluster' requires from 2 to 3 parameters: <addresses pattern or cluster name>, <name of remote database>, <name of remote table>. 

0 rows in set. Elapsed: 0.001 sec. 
```
{
    const Settings & settings = context.getSettingsRef();
    bool random_shard_insert = settings.insert_distributed_one_random_shard && !storage.has_sharding_key;
    if (random_shard_insert)
    {
        writeAsyncImpl(block, storage.getRandomShardIndex(cluster->getShardsInfo()));
    }
    else
    {
        if (storage.getShardingKeyExpr() && (cluster->getShardsInfo().size() > 1))
            return writeSplitAsync(block);
        writeAsyncImpl(block);
        ++inserted_blocks;
    }
}
std::string DistributedBlockOutputStream::getCurrentStateDescription()