操作准备
版本升级 > 19.11.7.40 升级到 20.9.2.20
系统版本 > CentOS Linux release 7.4.1708 (Core) ( #cat /etc/redhat-release)
显示命令：> yum list installed 'clickhouse*'
卸载命令: > yum -y remove ....
安装命令: > sudo yum -y localinstall clickhouse-*.rpm
升级流程
下载新版本文件(配置文件需要安装后获取并配置)
下载地址： https://mirrors.tuna.tsinghua.edu.cn/clickhouse/
-rw-r--r-- 1 root root 126272 10月 22 14:07 clickhouse-client-20.9.2.20-2.noarch.rpm
-rw-r--r-- 1 root root 141936506 10月 22 14:07 clickhouse-common-static-20.9.2.20-2.x86_64.rpm
-rw-r--r-- 1 root root 1574898417 10月 22 14:07 clickhouse-common-static-dbg-20.9.2.20-2.x86_64.rpm
-rw-r--r-- 1 root root 150248 10月 22 14:07 clickhouse-server-20.9.2.20-2.noarch.rpm
-rw-r--r-- 1 root root 33788 10月 22 14:09 config.xml
-rw-r--r-- 1 root root 1981 10月 22 14:09 metrika.xml
-rw-r--r-- 1 root root 6400 10月 22 14:07 users.xml
老系统关闭命令：
sudo /etc/init.d/clickhouse-server stop 建议：备份老系统配置文件
升级命令：（在新版本rpm包目录下）
yum upgrade *.rpm -y
1回滚命令(如果升级失败 可以进行回滚操作)
/etc/init.d/clickhouse-server stop yum downgrade clickhouse-server-common-18.14.15-1.el7.x86_64 clickhouse-server-18.14.15-1.el7.x86_64 clickhouse-common-static-18.14.15-1.el7.x86_64 clickhouse-client-18.14.15-1.el7.x86_64 -y
替换配置文件后启动
新系统启动命令
sudo systemctl start clickhouse-server
sudo systemctl stop clickhouse-server
sudo systemctl status clickhouse-server
操作过程中的问题
使用sudo /etc/init.d/clickhouse-server restart 启动命令
报错：Init script is already running
只能使用命令 sudo systemctl start clickhouse-server
https://github.com/ClickHouse/ClickHouse/issues/14861
升级后，把19的配置文件选项 逐步复制到20.9.2.20版本的配置文件
启动报错
2020.10.21 17:57:48.758439 [ 114835 ] {} <Error> Application: DB::Exception: A setting 'max_query_size' appeared at top level in config /etc/clickhouse-server/config.xml. But it is user-level setting that should be located in users.xml inside <profiles> section for specific profile. You can add it to <profiles><default> if you want to change default value of this setting. You can also disable the check - specify <skip_check_for_incorrect_settings>1</skip_check_for_incorrect_settings> in the main configuration file.
需要下config.xml中取消配置项 max_query_size
