No rows are written, though. Still, this may be problematic when this insert fails due to the `too many parts` error, which leads to the parent insert also failing. I haven't reproduced this failure exactly (complicated to do on localhost), but seen it happen for a ClickHouse user in Yandex.

Apparently this only happens with `insert_distributed_sync = 1`.

Cluster config:
```
        <weighted>
            <shard>
                <weight>100</weight>
                <replica>
                    <host>127.0.0.2</host>
                    <port>9000</port>
                </replica>
            </shard>
            <shard>
                <weight>0</weight>
                <replica>
                    <host>127.0.0.3</host>
                    <port>9000</port>
                </replica>
            </shard>
            <shard>
                <weight>100</weight>
                <replica>
                    <host>127.0.0.4</host>
                    <port>9000</port>
                </replica>
            </shard>
        </weighted>
```

Queries:

```
create table t_local (a int) engine MergeTree order by (a);

create table t_dist (a int) engine Distributed(weighted, 'default', 't_local', cityHash64(a));

set insert_distributed_sync = 1;

select written_rows, query_id from system.query_log where initial_query_id = '4c93852e-bdcb-436a-9ad3-4953ccedfcdc' and type != 1;
```

In the query log we see that the query is sent to all three shards, including the one with zero weight, but no rows are sent there.
```
SELECT 
    written_rows,
    query_id
FROM system.query_log
WHERE (initial_query_id = '4c93852e-bdcb-436a-9ad3-4953ccedfcdc') AND (type != 1)

┌─written_rows─┬─query_id─────────────────────────────┐
│            0 │ 177294a7-5612-45ef-bb57-2b36b73d709f │
│       499720 │ 02d724ae-5840-4805-9e5f-747a85332545 │
│       500280 │ a4692444-5409-4aec-a821-d9095e912ca1 │
│      1000000 │ 4c93852e-bdcb-436a-9ad3-4953ccedfcdc │
└──────────────┴──────────────────────────────────────┘
```

For more fun, try the `Log` engine for `t_local` -- the insert deadlocks: https://github.com/ClickHouse/ClickHouse/issues/14570
String remote_table = engine_args[2]->as<ASTLiteral &>().value.safeGet<String>();
        const auto & sharding_key = engine_args.size() >= 4 ? engine_args[3] : nullptr;
        const auto & storage_policy = engine_args.size() >= 5 ? engine_args[4]->as<ASTLiteral &>().value.safeGet<String>() : "default";
        
        if (sharding_key)
        {
            auto sharding_expr = buildShardingKeyExpression(sharding_key, args.context, args.columns.getAllPhysical(), true);
            const Block & block = sharding_expr->getSampleBlock();
            if (block.columns() != 1)
                throw Exception("Sharding expression must return exactly one column", ErrorCodes::INCORRECT_NUMBER_OF_COLUMNS);
            auto type = block.getByPosition(0).type;
            if (!type->isValueRepresentedByInteger())
                throw Exception("Sharding expression has type " + type->getName() +
                    ", but should be one of integer type", ErrorCodes::TYPE_MISMATCH);
        }
        return StorageDistributed::create(
            args.table_id, args.columns, args.constraints,
            remote_database, remote_table, cluster_name,
            args.context,
            sharding_key,
            storage_policy,
            args.relative_data_path,
            args.attach);
    },
    {
        .source_access_type = AccessType::REMOTE,
    });
}
}