**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 String & table_zookeeper_path, const ReplicatedMergeTreeLogEntryData & entry, bool wait_for_non_active)
{
    LOG_DEBUG(log, "Waiting for all replicas to process {}", entry.znode_name);
    auto zookeeper = getZooKeeper();
    Strings replicas = zookeeper->getChildren(fs::path(table_zookeeper_path) / "replicas");
    Strings unwaited;
    for (const String & replica : replicas)
    {
        if (wait_for_non_active || zookeeper->exists(fs::path(table_zookeeper_path) / "replicas" / replica / "is_active"))
        {
            if (!waitForTableReplicaToProcessLogEntry(table_zookeeper_path, replica, entry, wait_for_non_active))
                unwaited.push_back(replica);
        }
        else
        {
            unwaited.push_back(replica);
        }
    }
    LOG_DEBUG(log, "Finished waiting for all replicas to process {}", entry.znode_name);
    return unwaited;
}
Strings StorageReplicatedMergeTree::waitForAllReplicasToProcessLogEntry(