8 安裝mysql 8.1 方式一(離線安裝，已經下載好了安裝包) 8.1.1 卸載舊版本mysql及插件
（1）、查看 rpm -qa | grep mysql
（2）、卸載 rpm -e mysql-libs-5.1.73-7.el6.x86_64 --nodeps --nodeps 忽略其它依賴，直接卸載 8.1.2 安裝依賴perl yum install -y perl 8.1.3 安裝Mysql（重點）
（1）上傳、解壓 文件；
（2）rpm依次安裝4個應用程序，命令：rpm -ivh xxx.rpm;
rpm -ivh MySQL-client-5.6.28.1.e16.x86_64.rpm
rpm -ivh MySQL-devel-5.6.28.1.e16.x86_64.rpm
rpm -ivh numactl-2.0.9-2.e16.x86_64.rpm
rpm -ivh MySQL-server-5.6.28.1.e16.x86_64.rpm
Tips: 如果Mysql-server安裝失敗，則查看是否是系統自帶低版本mysql-lib庫產生沖突，如果是這個原因，則卸載低版本mysql-lib庫： rpm -e mysql-libs-5.1.71-1.el6.x86_64 8.1.4
上傳配置文件my.cnf到/etc/目錄下 目的：這個my.cnf文件，已經配置好了相關的設置，編碼使用的是utf-8。
[client] port = 3306 default-character-set = utf8mb4 [mysqld] port = 3306 user = mysql bind-address = 0.0.0.0 server-id = 1 init-connect = 'SET NAMES utf8mb4' character-set-server = utf8mb4 skip-name-resolve skip-external-locking #skip-networking back_log = 300 max_connections = 1000 max_connect_errors = 6000 open_files_limit = 65535 table_open_cache = 128 max_allowed_packet = 4M binlog_cache_size = 1M max_heap_table_size = 8M tmp_table_size = 16M read_buffer_size = 2M read_rnd_buffer_size = 8M sort_buffer_size = 8M join_buffer_size = 8M key_buffer_size = 4M thread_cache_size = 8 query_cache_type = 1 query_cache_size = 8M query_cache_limit = 2M ft_min_word_len = 4 log_bin = mysql-bin binlog_format = mixed expire_logs_days = 10 slow_query_log = 1 long_query_time = 1 performance_schema = 0 explicit_defaults_for_timestamp lower_case_table_names = 1 default_storage_engine = InnoDB #default-storage-engine = MyISAM innodb_file_per_table = 1 innodb_open_files = 500 innodb_buffer_pool_size = 64M innodb_write_io_threads = 4 innodb_read_io_threads = 4 innodb_thread_concurrency = 0 innodb_purge_threads = 1 innodb_flush_log_at_trx_commit = 2 innodb_log_buffer_size = 2M innodb_log_file_size = 32M innodb_log_files_in_group = 3 innodb_max_dirty_pages_pct = 90 innodb_lock_wait_timeout = 120 bulk_insert_buffer_size = 8M myisam_sort_buffer_size = 8M myisam_max_sort_file_size = 10G myisam_repair_threads = 1 interactive_timeout = 28800 wait_timeout = 28800 [mysqldump] quick max_allowed_packet = 16M [myisamchk] key_buffer_size = 8M sort_buffer_size = 8M read_buffer = 4M write_buffer = 4M
8.1.5 初始化mysql /usr/bin/mysql_install_db
8.1.6 啟動Mysql service mysql start 8.1.7 重置密碼（重點）
（1）查看初始密碼 cat /root/.mysql_secret
（2）使用初始密碼登陸 mysql -u root –pFeejxrrkzR544vGR
（3）修改密碼 set password=password(‘111111’);
8.1.8 遠程授權 遠程授權的目的：讓其他的主機、用戶能夠訪問服務器上的mysql數據庫。授權命令如下：
grant all privileges on *.* to 'root'@'%' identified by '123456' with grant option; flush privileges;