mysql8.0初探:(一)安裝和初始化使用
阿新 • • 發佈：2018-04-26
mysql 8.0雖然很奇怪,mysql5.7的下一個版本居然不是5.8,而是直接跳到8.0,不過特性和功能優化改善很多.
之前看過很多文章都說mysql8.0變化很大,但是一頓測試下來,大部分操作還是比較一致,某些操作不一樣而已.
下面來一步步看有什麽大差別,本篇文章只說兩個方面.
安裝
因為mysql官方和以往一樣,給出二進制包的方式,所以和以往安裝方式並沒有太大差別
首先官網下載二進制包,然後就可以正常解壓縮安裝了,我習慣了下面的方式
tar xf mysql-8.0.11-linux-glibc2.12-x86_64.tar.gz mv mysql-8.0.11-linux-glibc2.12-x86_64 /usr/local/ cd /usr/local/ ln -sf mysql-8.0.11-linux-glibc2.12-x86_64/ mysql80. mkdir -p /data/mysql/data80 groupadd mysql useradd -g mysql -s /sbin/nologin mysql
其實二進制包也沒什麽安裝概念,都是拿來就用
初始化使用
1.初始化
其實和mysql5.7沒什麽差別
/usr/local/mysql80/bin/mysqld --defaults-file=/usr/local/mysql80/my.cnf --initialize
然後密碼也在之前一樣的地方
sed -n '/password/p' /data/mysql/data80/mysql.err .....A temporary password is generated for root@localhost: %pqGI?ATQ4fg,
記得啟動前要把權限設置一下再啟動
chown -R mysql:mysql /data/mysql/data* /usr/local/mysql80/support-files/mysql.server start
先用mysql8.0自帶的mysql客戶端和初始化密碼登進去,後面會說為什麽要這麽幹
/usr/local/mysql80/bin/mysql -uroot -p'%pqGI?ATQ4fg' -S /tmp/mysql80.sock -P3308
改密碼方式也是和5.7一樣的
mysql> alter user 'root'@'localhost' identified by '123';
mysql> set password for 'root'@'localhost'=password('123');
mysql> update mysql.user set authentication_string=password('123') where user='root' and Host = 'localhost';
mysql> flush privileges;這個時候,你如果用默認的mysql客戶端登陸,可能就會有這個報錯
mysql -uroot -p123 -P3308 -S /tmp/mysql80.sock mysql: [Warning] Using a password on the command line interface can be insecure. ERROR 2059 (HY000): Authentication plugin 'caching_sha2_password' cannot be loaded: /usr/local/mysql/lib/plugin/caching_sha2_password.so: cannot open shared object file: No such file or directory
在mysql5.7環境裏,雖然可以設置default_authentication_plugin來改變認證加密方式,但是一般人不會去設置.在mysql8.0下,默認變成了default_authentication_plugin=caching_sha2_password,包括你剛初始化的root用戶也是這個認證加密方式,這樣的結果是讓你除非用新的協議驅動,例如必須用8.0自帶的mysql客戶端才行,不然就連接不上數據庫.這樣就必然造成不兼容的情況,幸好,是可以改回舊的方式的.
vim my.cnf [mysqld] default_authentication_plugin=mysql_native_password
但是,這個參數只對新授權的用戶生效,舊的root密碼還是用舊的方式,類似下面這樣
#先用新客戶端登陸 /usr/local/mysql80/bin/mysql -uroot -p123 -P3308 -S /tmp/mysql80.sock #查看各用戶情況 mysql> select Host,User,plugin,authentication_string from mysql.user; +-----------+------------------+-----------------------+------------------------------------------------------------------------+ | Host | User | plugin | authentication_string | +-----------+------------------+-----------------------+------------------------------------------------------------------------+ | localhost | mysql.infoschema | mysql_native_password | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE | | localhost | mysql.session | mysql_native_password | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE | | localhost | mysql.sys | mysql_native_password | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE | | localhost | root | caching_sha2_password | $A$005$.Sf}Q/Jh>3b6CjI5/vMJVDIQbS1dbFWaCVuiby7aX3ZY4lB6/M7Vvny5DUA | +-----------+------------------+-----------------------+------------------------------------------------------------------------+ 4 rows in set (0.00 sec)
可以看到plugin是不一樣的,密碼的加密方式也很明顯不一致造成差異.
然後我們再新建一個用戶,就可以看到是和以前一樣了
mysql> select Host,User,plugin,authentication_string from mysql.user; +-----------+------------------+-----------------------+------------------------------------------------------------------------+ | Host | User | plugin | authentication_string | +-----------+------------------+-----------------------+------------------------------------------------------------------------+ | % | sroot | mysql_native_password | *E56A114692FE0DE073F9A1DD68A00EEB9703F3F1 | | localhost | mysql.infoschema | mysql_native_password | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE | | localhost | mysql.session | mysql_native_password | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE | | localhost | mysql.sys | mysql_native_password | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE | | localhost | root | caching_sha2_password | $A$005$.Sf}Q/Jh>3b6CjI5/vMJVDIQbS1dbFWaCVuiby7aX3ZY4lB6/M7Vvny5DUA | +-----------+------------------+-----------------------+------------------------------------------------------------------------+ 5 rows in set (0.00 sec)
再次用默認的mysql客戶端登陸
mysql -usroot -p123123 -P3308 -S /tmp/mysql80.sock mysql> \s -------------- mysql Ver 14.14 Distrib 5.7.20, for linux-glibc2.12 (x86_64) using EditLine wrapper Connection id: 17 Current database: Current user: sroot@localhost SSL: Not in use Current pager: stdout Using outfile: '' Using delimiter: ; Server version: 8.0.11 MySQL Community Server - GPL Protocol version: 10 Connection: Localhost via UNIX socket Server characterset: utf8 Db characterset: utf8 Client characterset: utf8 Conn. characterset: utf8 UNIX socket: /tmp/mysql80.sock Uptime: 1 hour 25 min 18 sec Threads: 2 Questions: 120 Slow queries: 0 Opens: 230 Flush tables: 2 Open tables: 203 Queries per second avg: 0.023 --------------
解決了一個兼容性問題了.
2.授權
上面說了創建一個用戶,在mysql8.0創建用戶和授權和之前不太一樣.其實也不能說不一樣,而是說更嚴格,需要先創建用戶和設置密碼,然後才能授權.
#先創建一個用戶 create user 'sroot'@'%' identified by '123123'; #再進行授權 grant all privileges on *.* to 'sroot'@'%' with grant option;
如果按以前的方式來做,那就會報語法錯誤
grant all privileges on *.* to 'sroot'@'%' identified by '123123'; ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'identified by '123123'' at line 1
所以授權用戶要註意方法了
3.參數變更
因為版面有限,我沒有貼出my.cnf文件,而由於一些特性的原因,mysql8.0一些配置和之前的不太一樣,下面來列舉我發現的.
query_cache徹底消失了,在mysql5.7還需要手動設置為關閉,現在可以不用理會了,所以相應的兩個參數就可以註釋掉了
#query_cache_size=0 #query_cache_type=0
innodb_undo_logs不能再設置了,在mysql8.0裏,undo獨立表空間是默認開啟的,而且值為2,也就是默認兩個,但是不能設innodb_undo_logs這個參數來指定回滾段大少,回滾段默認就是128
#innodb_undo_logs
其實暫時沒發現,待發現再補上
然後也發現系統表現在都是innodb引擎,其實之前也在特性裏看到了.
mysql8.0初探:(一)安裝和初始化使用