**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'
```
}
        else
        {
            
            part->is_temp = false;
            part->renameTo(fs::path("detached") / part_name, true);
        }
    }
    catch (const Exception & e)
    {
        
        
        if (e.code() == ErrorCodes::DIRECTORY_ALREADY_EXISTS)
            return false;
        throw;
    }
    catch (...)
    {
        if (!to_detached)
            write_part_log(ExecutionStatus::fromCurrentException());
        throw;
    }
    ProfileEvents::increment(ProfileEvents::ReplicatedPartFetches);
    if (part_to_clone)
        LOG_DEBUG(log, "Cloned part {} from {}{}", part_name, part_to_clone->name, to_detached ? " (to 'detached' directory)" : "");
    else
        LOG_DEBUG(log, "Fetched part {} from {}{}", part_name, source_replica_path, to_detached ? " (to 'detached' directory)" : "");
    return true;
}
bool StorageReplicatedMergeTree::fetchExistsPart(const String & part_name, const StorageMetadataPtr & metadata_snapshot,