**Use case**

Currently, `system.replicas` table has `total_replicas` and `active_replicas` columns which are useful to check/alert when some replicas are down. One problem, these columns are numbers. They tell when there is a problem, but you need to further check ZooKeeper or query all the nodes to detect what exact replicas (hosts) are down/inactive/have problems.

**Describe the solution you'd like**

Add a replicas column maybe as a map which would contain the replica name, and it's status. Or, add 2 array columns with `replica_names` and `active_replica_names`

**Alternative**

Something along the line

```sql
select path, value from system.zookeeper where path IN (
    select concat(path, '/', name) from system.zookeeper where path in (select concat(zookeeper_path, '/replicas') from system.replicas)
)
and name = 'is_active'
```
String desired_checksums_str = zookeeper->get(fs::path(part_path) / "checksums");
                desired_checksums = MinimalisticDataPartChecksums::deserializeFrom(desired_checksums_str);
            }
            if (source_part_checksums == desired_checksums)
            {
                LOG_TRACE(log, "Found local part {} with the same checksums as {}", source_part->name, part_name);
                part_to_clone = source_part;
            }
        }
    }
    ReplicatedMergeTreeAddress address;
    ConnectionTimeouts timeouts;
    String interserver_scheme;
    InterserverCredentialsPtr credentials;
    std::optional<CurrentlySubmergingEmergingTagger> tagger_ptr;
    std::function<MutableDataPartPtr()> get_part;
    if (part_to_clone)
    {
        get_part = [&, part_to_clone]()
        {
            return cloneAndLoadDataPartOnSameDisk(part_to_clone, "tmp_clone_", part_info, metadata_snapshot);
        };
    }
    else
    {
        address.fromString(zookeeper->get(fs::path(source_replica_path) / "host"));
        timeouts = getFetchPartHTTPTimeouts(getContext());
        credentials = getContext()->getInterserverCredentials();
        interserver_scheme = getContext()->getInterserverScheme();
        get_part = [&, address, timeouts, credentials, interserver_scheme]()