**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'
```
{
    if (!queue_update_in_progress)
    {
        last_queue_update_start_time.store(time(nullptr));
        queue_update_in_progress = true;
    }
    try
    {
        queue.pullLogsToQueue(getZooKeeper(), queue_updating_task->getWatchCallback());
        last_queue_update_finish_time.store(time(nullptr));
        queue_update_in_progress = false;
    }
    catch (const Coordination::Exception & e)
    {
        tryLogCurrentException(log, __PRETTY_FUNCTION__);
        if (e.code == Coordination::Error::ZSESSIONEXPIRED)
        {
            restarting_thread.wakeup();
            return;
        }
        queue_updating_task->scheduleAfter(QUEUE_UPDATE_ERROR_SLEEP_MS);
    }
    catch (...)
    {
        tryLogCurrentException(log, __PRETTY_FUNCTION__);
        queue_updating_task->scheduleAfter(QUEUE_UPDATE_ERROR_SLEEP_MS);
    }
}
void StorageReplicatedMergeTree::mutationsUpdatingTask()