**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'
```
const ASTPtr & partition,
    const StorageMetadataPtr & metadata_snapshot,
    bool attach_part,
    ContextPtr query_context)
{
    assertNotReadonly();
    PartitionCommandsResultInfo results;
    PartsTemporaryRename renamed_parts(*this, "detached/");
    MutableDataPartsVector loaded_parts = tryLoadPartsToAttach(partition, attach_part, query_context, renamed_parts);
    
    ReplicatedMergeTreeSink output(*this, metadata_snapshot, 0, 0, 0, false, false, query_context,
        true);
    for (size_t i = 0; i < loaded_parts.size(); ++i)
    {
        const String old_name = loaded_parts[i]->name;
        output.writeExistingPart(loaded_parts[i]);
        renamed_parts.old_and_new_names[i].first.clear();
        LOG_DEBUG(log, "Attached part {} as {}", old_name, loaded_parts[i]->name);
        results.push_back(PartitionCommandResultInfo{
            .partition_id = loaded_parts[i]->info.partition_id,
            .part_name = loaded_parts[i]->name,
            .old_part_name = old_name,
        });
    }
    return results;
}
void StorageReplicatedMergeTree::checkTableCanBeDropped() const