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 ConnectionPoolPtr & connection_pool = shard_info.per_replica_pools.at(job.replica_index);
                    if (!connection_pool)
                        throw Exception("Connection pool for replica " + replica.readableString() + " does not exist", ErrorCodes::LOGICAL_ERROR);
                    job.connection_entry = connection_pool->get(timeouts, &settings);
                    if (job.connection_entry.isNull())
                        throw Exception("Got empty connection for replica" + replica.readableString(), ErrorCodes::LOGICAL_ERROR);
                }
                if (throttler)
                    job.connection_entry->setThrottler(throttler);
                job.stream = std::make_shared<RemoteBlockOutputStream>(*job.connection_entry, timeouts, query_string, settings, context.getClientInfo());
                job.stream->writePrefix();
            }
            CurrentMetrics::Increment metric_increment{CurrentMetrics::DistributedSend};
            Block adopted_shard_block = adoptBlock(job.stream->getHeader(), shard_block, log);
            job.stream->write(adopted_shard_block);
        }
        else 
        {
            if (!job.stream)
            {
                
                job.local_context = std::make_unique<Context>(context);
                
                
                
                
                
                
                auto copy_query_ast = query_ast->clone();
                InterpreterInsertQuery interp(copy_query_ast, *job.local_context);