Hello,

after updating clickhouse from 21.2.3.15-2 to 21.3.2.5-2 I see those warnings :

 `<Warning> default.osb4_reverse.DirectoryMonitor: Structure does not match (remote: Path LowCardinality(String) ColumnLowCardinality(size = 0, UInt8(size = 0), ColumnUnique(size = 1, String(size = 1))), Value Float64 Float64(size = 0), Time UInt32 UInt32(size = 0), Date Date UInt16(size = 0), Timestamp UInt32 UInt32(size = 0), local: Path LowCardinality(String) ColumnLowCardinality(size = 0, UInt16(size = 0), ColumnUnique(size = 1, String(size = 1))), Value Float64 Float64(size = 0), Time UInt32 UInt32(size = 0), Date Date UInt16(size = 0), Timestamp UInt32 UInt32(size = 0)), implicit conversion will be done`

I think this is related to https://github.com/ClickHouse/ClickHouse/pull/19947

The only difference between remote and local I found inside this log is :

ColumnLowCardinality(size = 0, UInt8(size = 0) to
ColumnLowCardinality(size = 0, UInt16(size = 0)

But I don't see the difference between the tables.

```
SHOW CREATE TABLE default.osb4_reverse

CREATE TABLE default.osb4_reverse
(
    `Path` LowCardinality(String) CODEC(ZSTD(15)),
    `Value` Float64 CODEC(Gorilla, ZSTD(22)),
    `Time` UInt32 CODEC(DoubleDelta, ZSTD(15)),
    `Date` Date CODEC(Delta(2), ZSTD(22)),
    `Timestamp` UInt32 CODEC(ZSTD(15))
)
ENGINE = Distributed('osb4_hpc_metrics', '', 'osb4_reverse', rand())


CREATE TABLE osb4_metrics_r0.osb4_reverse
(
    `Path` LowCardinality(String) CODEC(ZSTD(15)),
    `Value` Float64 CODEC(Gorilla, ZSTD(22)),
    `Time` UInt32 CODEC(DoubleDelta, ZSTD(15)),
    `Date` Date CODEC(Delta(2), ZSTD(22)),
    `Timestamp` UInt32 CODEC(ZSTD(15))
)
ENGINE = ReplicatedReplacingMergeTree('/clickhouse/clusters/osb4_hpc_metrics/tables/{table4}/data', '{host2}')
PARTITION BY toYYYYMM(Date)
ORDER BY (Path, Time)
TTL Date + toIntervalMonth(6)
SETTINGS index_granularity = 8192
```

Any hints ?

Ralph
}
        
        const std::string block_file_path(path + '/' + file_name);
        createHardLink(first_file_tmp_path, block_file_path);
        auto dir_sync_guard = make_directory_sync_guard(*it);
    }
    ++it;
    
    for (; it != dir_names.end(); ++it)
    {
        const std::string path(disk_path + data_path + *it);
        Poco::File(path).createDirectory();
        const std::string block_file_path(path + '/' + toString(storage.file_names_increment.get()) + ".bin");
        createHardLink(first_file_tmp_path, block_file_path);
        auto dir_sync_guard = make_directory_sync_guard(*it);
    }
    auto file_size = Poco::File(first_file_tmp_path).getSize();
    
    
    Poco::File(first_file_tmp_path).remove();
    
    auto sleep_ms = context.getSettingsRef().distributed_directory_monitor_sleep_time_ms;
    for (const auto & dir_name : dir_names)
    {
        auto & directory_monitor = storage.requireDirectoryMonitor(disk, dir_name);
        directory_monitor.addAndSchedule(file_size, sleep_ms.totalMilliseconds());
    }
}
}