**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'
```
throw Exception(ErrorCodes::DUPLICATE_DATA_PART, "Part {} already exists on replica {} on path {}", lost_part_name, replica, current_part_path);
                }
            }
            getCommitPartOps(ops, new_data_part);
            Coordination::Responses responses;
            if (auto code = zookeeper->tryMulti(ops, responses); code == Coordination::Error::ZOK)
            {
                transaction.commit();
                break;
            }
            else if (code == Coordination::Error::ZBADVERSION)
            {
                LOG_INFO(log, "Looks like new replica appearead while creating new empty part, will retry");
            }
            else
            {
                zkutil::KeeperMultiException::check(code, ops, responses);
            }
        }
    }
    catch (const Exception & ex)
    {
        LOG_WARNING(log, "Cannot commit empty part {} with error {}", lost_part_name, ex.displayText());
        return false;
    }
    LOG_INFO(log, "Created empty part {} instead of lost part", lost_part_name);
    return true;
}
}