**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'
```
}
            for (auto & future : remove_futures)
            {
                auto response = future.get();
                if (response.error == Coordination::Error::ZOK || response.error == Coordination::Error::ZNONODE)
                    continue;
                if (Coordination::isHardwareError(response.error))
                {
                    success = false;
                    continue;
                }
                throw Coordination::Exception(response.error);
            }
        }
        catch (Coordination::Exception & e)
        {
            success = false;
            if (Coordination::isHardwareError(e.code))
                tryLogCurrentException(log, __PRETTY_FUNCTION__);
            else
                throw;
        }
        if (!success && num_tries < max_retries)
            std::this_thread::sleep_for(std::chrono::milliseconds(1000));
    }
    return success;
}
void StorageReplicatedMergeTree::removePartsFromZooKeeper(
    zkutil::ZooKeeperPtr & zookeeper, const Strings & part_names, NameSet * parts_should_be_retried)
{