1. 验证系统是否符合安装条件
ClickHouse可以在任何具有x86_64，AArch64或PowerPC64LE CPU架构的Linux，FreeBSD或Mac OS X上运行。虽然预构建的二进制文件通常是为x86 _64编译并利用SSE 4.2指令集，但除非另有说明，否则使用支持它的CPU将成为额外的系统要求。这是检查当前CPU是否支持SSE 4.2的命令：
grep -q sse4_2 /proc/cpuinfo && echo "SSE 4.2 supported" || echo "SSE 4.2 not supported" SSE 4.2 supported
2. 官网安装指南（在线）
https://clickhouse.tech/#quick-start 很清晰。
sudo yum install yum-utils sudo rpm --import https://repo.clickhouse.tech/CLICKHOUSE-KEY.GPG sudo yum-config-manager --add-repo https://repo.clickhouse.tech/rpm/clickhouse.repo sudo yum install clickhouse-server clickhouse-client sudo /etc/init.d/clickhouse-server start clickhouse-client
3. 报错问题处理
3.1 启动 clickhouse-client 报错
[root@tcloud ~]# clickhouse-client ClickHouse client version 21.6.6.51 (official build). Connecting to localhost:9000 as user default. Code: 210. DB::NetException: Connection refused (localhost:9000)
在网络上寻求帮助，修改配置文件：
vim /etc/clickhouse-server/config.xml # listen_host 只留这个配置 <listen_host>::</listen_host>
启动依然报错。
3.2 启动 clickhouse-server 报错
反复查询 Code: 210. DB::NetException: Connection refused (localhost:9000) 问题，几乎都是改上述配置文件，我就查询了一下 clickhouse-server 的状态，果不其然是 server 都没启动起来。
[root@tcloud ~]# service clickhouse-server status Now there is no clickhouse-server process. Usage: /etc/init.d/clickhouse-server {start|stop|status|restart|forcestop|forcerestart|reload|condstart|condstop|condrestart|condreload|initdb}
然后启动 server 居然也报错：
[root@tcloud ~]# service clickhouse-server start Init script is already running
求助无私程序员，解决：原文链接 https://www.gbase8.cn/5233 ，主要问题是在REdhat 7和之后的操作系统，需要用systemctl启动才可以。
[root@tcloud ~]# systemctl start clickhouse-server.service [root@tcloud ~]# systemctl status clickhouse-server.service ● clickhouse-server.service - ClickHouse Server (analytic DBMS for big data) Loaded: loaded (/etc/systemd/system/clickhouse-server.service; enabled; vendor preset: disabled) Active: active (running) since Wed 2021-07-07 09:57:34 CST; 25s ago Main PID: 6223 (clckhouse-watch) CGroup: /system.slice/clickhouse-server.service ├─6223 clickhouse-watchdog --config=/etc/clickhouse-server/config.xml --pid-file=/run/clickhouse-server/clickhouse-server.pid └─6224 /usr/bin/clickhouse-server --config=/etc/clickhouse-server/config.xml --pid-file=/run/clickhouse-server/clickhouse-server.pid
服务端启动后再次启动 clickhouse-client 并测试 OK
[root@tcloud ~]# clickhouse-client ClickHouse client version 21.6.6.51 (official build). Connecting to localhost:9000 as user default. Connected to ClickHouse server version 21.6.6 revision 54448. tcloud :) show databases; SHOW DATABASES Query id: b6c83d01-93e0-4688-bc42-857de4dab0ce ┌─name────┐ │ default │ │ system │ └─────────┘ 2 rows in set. Elapsed: 0.004 sec.
3.3 clickhouse-client 启动报错探究
那 Code: 210. DB::NetException: Connection refused (localhost:9000) 报错究竟是server未启动，还是listen_host未配置的原因，为一探究竟，又把 /etc/clickhouse-server/config.xml 文件改回原始状态。
又报错了
[root@tcloud ~]# clickhouse-client ClickHouse client version 21.6.6.51 (official build). Connecting to localhost:9000 as user default. Code: 210. DB::NetException: Connection refused (localhost:9000)
结论： 需要配置 /etc/clickhouse-server/config.xml 文件，且需要正确启动server服务。
4.总结
ClickHouse的在线安装还是比较简单的，当然，有的官网更新不够频繁，遇坑不怕，太多无私的分享者，感激！
