**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'
```
bool waitForReplicaToProcessLogEntry(const String & replica_name, const ReplicatedMergeTreeLogEntryData & entry, bool wait_for_non_active = true);
    
    void assertNotReadonly() const;
    
    
    
    
    bool getFakePartCoveringAllPartsInPartition(const String & partition_id, MergeTreePartInfo & part_info,
                                                std::optional<EphemeralLockInZooKeeper> & delimiting_block_lock, bool for_replace_range = false);
    
    mutable std::unordered_set<std::string> existing_nodes_cache;
    mutable std::mutex existing_nodes_cache_mutex;
    bool existsNodeCached(const std::string & path) const;
    void getClearBlocksInPartitionOps(Coordination::Requests & ops, zkutil::ZooKeeper & zookeeper, const String & partition_id, Int64 min_block_num, Int64 max_block_num);
    
    void clearBlocksInPartition(
        zkutil::ZooKeeper & zookeeper, const String & partition_id, Int64 min_block_num, Int64 max_block_num);
    
    ReplicatedMergeTreeAddress getReplicatedMergeTreeAddress() const;
    bool dropAllPartsInPartition(
        zkutil::ZooKeeper & zookeeper, String & partition_id, LogEntry & entry, ContextPtr query_context, bool detach);
    void dropPartNoWaitNoThrow(const String & part_name) override;
    void dropPart(const String & part_name, bool detach, ContextPtr query_context) override;
    
    void dropPartition(const ASTPtr & partition, bool detach, ContextPtr query_context) override;
    PartitionCommandsResultInfo attachPartition(const ASTPtr & partition, const StorageMetadataPtr & metadata_snapshot, bool part, ContextPtr query_context) override;
    void replacePartitionFrom(const StoragePtr & source_table, const ASTPtr & partition, bool replace, ContextPtr query_context) override;
    void movePartitionToTable(const StoragePtr & dest_table, const ASTPtr & partition, ContextPtr query_context) override;
    void movePartitionToShard(const ASTPtr & partition, bool move_part, const String & to, ContextPtr query_context) override;
    void fetchPartition(