【ClickHouse安装01】Linux环境在线安装单机版Code:210.DB + Init script is already running 问题处理

本文已参与「新人创作礼」活动，一起开启掘金创作之路。

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）

clickhouse.tech/#quick-star… 很清晰。

在这里插入图片描述

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 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。

在这里插入图片描述 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！