clickhouse集群部署

一、集群部署简介

部署的详情可以看官网
先部署两个server,三个keeper[zookeeper]
clickhouse之前依赖的存储是zookeeper,后来改为了keeper,官网给出了原因
所以这就决定了clickhouse有两种安装方式，依赖于keeper做存储或者依赖于zookeeper做存储

二、zookeeper作为存储

1.zookeeper安装

zookeeper安装可以看之前的文章

2.clickhouse部署

修改配置文件

2.1 修改listen_host

<listen_host>0.0.0.0listen_host>  

2.2 修改存储路径

    <path>/var/lib/clickhouse/path>

2.3 添加集群配置

<remote_servers>
        <cluster_2S_1R> 
            <shard>
                <internal_replication>trueinternal_replication>
                <replica>
                    <host>chnode1host>
                    <port>9000port>
                replica>
            shard>
            <shard>
                <internal_replication>trueinternal_replication>
                <replica>
                    <host>chnode2host>
                    <port>9000port>
                replica>
            shard>
        cluster_2S_1R>
    remote_servers>

<!--
注意，上面的写法是放到两个shard里，也可放到一个shard,下面是单一分片两副本的写法，如果放到不同的shard里macros的配置就得不同了
>
        <cluster_2S_1R> 
            <shard>
                <internal_replication>trueinternal_replication>
                <replica>
                    <host>chnode1host>
                    <port>9000port>
                replica>
                <replica>
                    <host>chnode2host>
                    <port>9000port>
                replica>
            shard>
        cluster_2S_1R>
    remote_servers>


-->

2.4配置zookeeper

<zookeeper>
        <node>
            <host>example1host>
            <port>2181port>
        node>
        <node>
            <host>example2host>
            <port>2181port>
        node>
        <node>
            <host>example3host>
            <port>2181port>
        node>
zookeeper>

2.5配置macros

    <macros>
      <shard>01shard>
      <replica>chnode1replica> 
    macros>

  <macros>
      <shard>01shard>
      <replica>chnode2replica> 
    macros>

3.启动clickhouse

systemctl start clickhouse-server.service
systemctl enable clickhouse-server.service

4.登录机器并检查集群

4.1登录

# 登录
clickhouse-client
# 查看集群信息
select * from system.clusters

4.2建表

CREATE TABLE t1 ON CLUSTER cluster_2S_1R
(
    `ts` DateTime,
    `uid` String,
    `biz` String
)
ENGINE = ReplicatedMergeTree('/clickhouse/test1/tables/{shard}/t1', '{replica}')
PARTITION BY toYYYYMMDD(ts)
ORDER BY ts
SETTINGS index_granularity = 8192


# 出现如下报错
Received exception from server (version 23.6.2):
Code: 159. DB::Exception: Received from localhost:9000. DB::Exception: Watching task /clickhouse/task_queue/ddl/query-0000000004 is executing longer than distributed_ddl_task_timeout (=180) seconds. There are 2 unfinished hosts (0 of them are currently active), they are going to execute the query in background. (TIMEOUT_EXCEEDED)
# 这个报错是某些ck服务异常才出现的报错，我这是因为我配置文件里的remote_server里的host ip写错了，相当于找不到服务了,修改后重启就好了

4.3 测试dml

目前DDL生效，但是插入数据在其他节点不生效
查看节点2的clickhouse日志，其中会有如下报错

2023.08.10 15:49:54.836507 [ 8514 ] {} <Error> test1.t1 (*****-48d4-44ed-9bad-2a03410321a9): auto DB::StorageReplicatedMergeTree::processQueueEntry(ReplicatedMergeTreeQueue::SelectedEntryPtr)::(anonymous class)::operator()(LogEntryPtr &) const: Code: 198. DB::Exception: Not found address of host: bj-ck3. (DNS_ERROR), Stack trace (when copying this message, always include the lines below):

可以看到这里是因为域名无法解析，因为ZooKeeper 里面存储的是hosts域名，不是IP，所以需要配置/etc/hosts

192.168.1.1    bj-ck1
192.168.1.2    bj-ck2
192.168.1.3    bj-ck3

ps: /etc/hosts的配置里，如果配置多个的话，是以第一个为准，其他都类似别名么
比如192.168.1.1配置如下:192.168.1.1 bj-1 bj-2
如果别的机器是以域名访问192.168.1.1，如果别的机器只配置了192.168.1.1 bj-2,其实是解析不到192.168.1.1的

三、keeper作为存储

ClickHouse Keeper 提供数据复制和分布式 DDL 查询执行的协调系统。 ClickHouse Keeper 与 Apache ZooKeeper 兼容。 此配置在端口 9181 上启用 ClickHouse Keeper。

注意：
如果出于任何原因更换或重建 Keeper 节点，请勿重复使用现有的 server_id。 例如，如果重建了server_id为2的Keeper节点，则将其server_id设置为4或更高。

分片和副本降低了分布式 DDL 的复杂性。 配置的值会自动替换到您的 DDL 查询中，从而简化您的 DDL。

1.安装并启动keeper

# 安装clickhouse-keeper
sudo apt-get install -y clickhouse-keeper
# 启用并启动clickhouse-keeper
sudo systemctl enable clickhouse-keeper
sudo systemctl start clickhouse-keeper
sudo systemctl status clickhouse-keeper

2.修改keeper配置文件keeper_config.xml

 <keeper_server>
            <tcp_port>9181tcp_port>

            
            <server_id>1server_id>

            <log_storage_path>/var/lib/clickhouse/coordination/logslog_storage_path>
            <snapshot_storage_path>/var/lib/clickhouse/coordination/snapshotssnapshot_storage_path>

            <coordination_settings>
                <operation_timeout_ms>10000operation_timeout_ms>
                <min_session_timeout_ms>10000min_session_timeout_ms>
                <session_timeout_ms>100000session_timeout_ms>
                <raft_logs_level>informationraft_logs_level>
                
            coordination_settings>

            
            <hostname_checks_enabled>truehostname_checks_enabled>
            
            
            <raft_configuration>
                <server>
                    <id>1id>
                    
                    <hostname>192.168.1.1hostname>
                    <port>9234port>
                server>
                <server>
                    <id>2id>
                    
                    <hostname>192.168.1.2hostname>
                    <port>9234port>
                server>
                <server>
                    <id>3id>
                    
                    <hostname>192.168.1.3hostname>
                    <port>9234port>
                server>
                

            raft_configuration>
    keeper_server>
    <clickhouse>
	    <zookeeper>
	        <node index="1">
	            <host>chnode1host>
	            <port>9181port>
	        node>
	        <node index="2">
	            <host>chnode2host>
	            <port>9181port>
	        node>
	        <node index="3">
	            <host>chnode3host>
	            <port>9181port>
	        node>
	    zookeeper>
   clickhouse>

3.clickhouse的配置

clickhouse的配置与zookeeper作为存储时的配置几乎一致，只需要把zookeeper的配置注释掉即可

ps: 这里还有个小插曲，使用keeper的时候发现dml的数据又一次不同步了，查看clickhouse-server.err.log,发现有如下报错

2023.08.16 11:19:00.782071 [ 8566 ] {} <Error> ConfigReloader: Error updating configuration from '/etc/clickhouse-server/config.xml' config.: Code: 999. Coordination::Exception: Connection loss, path: All connection tries failed while connecting to ZooKeeper

使用telnet后发现确实telnet不通，于是修改keeper的配置文件keeper_config.xml，添加如下内容

<listen_host>0.0.0.0</listen_host>

重启keeper

systemctl restart clickhouse-keeper