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
tryLogCurrentException(parent.log, "Failed to send batch due to");
                batch_broken = true;
            }
            else
                throw;
        }
        if (!batch_broken)
        {
            LOG_TRACE(parent.log, "Sent a batch of {} files.", file_indices.size());
            auto dir_sync_guard = getDirectorySyncGuard(dir_fsync, parent.disk, parent.relative_path);
            for (UInt64 file_index : file_indices)
                parent.markAsSend(file_index_to_path.at(file_index));
        }
        else
        {
            LOG_ERROR(parent.log, "Marking a batch of {} files as broken.", file_indices.size());
            for (UInt64 file_idx : file_indices)
            {
                auto file_path = file_index_to_path.find(file_idx);
                if (file_path != file_index_to_path.end())
                    parent.markAsBroken(file_path->second);
            }
        }
        file_indices.clear();
        total_rows = 0;
        total_bytes = 0;
        recovered = false;
        Poco::File{parent.current_batch_file_path}.setSize(0);
    }
    void writeText(WriteBuffer & out)