一. 准备工作
- 删除本地CentOS7中的mariadb：
首先，检查系统中是否已安装mariadb服务：
rpm -qa | grep mariadb
或
yum list installed | grep mariadb
如果已安装，则删除mariadb及其依赖的包：
yum -y remove mariadb-libs-5.5.44-2.el7.centos.x86_64
接下来，关闭防火墙：
firewall-cmd --state #查看防火墙状态 systemctl stop firewalld.service #关闭防火墙 systemctl is-enabled firewalld.service;echo $? #查看防火墙是否开机自启 systemctl disable firewalld.service #禁止防火墙开机启动
MySQL依赖于libaio库，安装libaio：
yum search libaio yum install libaio
- 下载安装包：
创建一个目录用于存放MySQL安装包：
mkdir /data cd /data/ yum -y install wget wget https://cdn.mysql.com//Downloads/MySQL-5.7/mysql-5.7.20-linux-glibc2.12-x86_64.tar.gz
- 解压并重命名：
解压MySQL安装包，并重命名目录：
tar -zxvf mysql-5.7.20-linux-glibc2.12-x86_64.tar.gz -C /data mv /data/mysql-5.7.20-linux-glibc2.12-x86_64/ /data/mysql57 mkdir mysql #数据目录与安装目录分离，便于以后MySQL升级
二. 安装MySQL
- 添加用户和组：
groupadd mysql useradd mysql -g mysql
- 配置文件/etc/my.cnf：
主要参数及取值如下（请根据实际环境调整，如内存配置参数等）：
[client] socket = /data/mysql/data/mysql.sock default-character-set=utf8mb4 #loose-local-infile=0 <p>[mysqld] log_bin_trust_function_creators=1 secure_file_priv='/tmp'</p><p>########dir settings######## basedir = /data/mysql57 datadir = /data/mysql/data pid-file = /data/mysql/data/mysql.pid socket = /data/mysql/data/mysql.sock tmpdir = /data/mysql/tmp log-bin = /data/mysql/mysql_log/mysql-bin log-error = /data/mysql/mysql_log/mysql.err general_log_file=/data/mysql/mysql_log/mysql.genlog slow_query_log_file = /data/mysql/mysql_log/mysql_slow_new.log relay_log = /data/mysql/mysql_log/relay.log</p><p>########server setting######## sql_mode = "ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION" server-id = 2022 port = 3306 character-set-server=utf8mb4 collation_server=utf8mb4_unicode_ci lower_case_table_names = 0 skip_name_resolve = 1</p><h1>max_connect_errors = 1000</h1><p>max_connections = 2000 thread_cache_size=256</p><h1>thread_stack= 262144</h1><h1>back_log=80</h1><p>max_allowed_packet = 134217728 event_scheduler = 1 local-infile=0</p><h1>lower_case_table_names = 1</h1><p>explicit_defaults_for_timestamp = 1 expire_logs_days = 15 log_bin_trust_function_creators =1</p><h4>.frm/.ibd files qty related</h4><p>open_files_limit=65535 innodb_open_files=65535 table_open_cache=65535 table_definition_cache=65535</p><h4>seesion buffer related</h4><p>read_buffer_size = 262144 read_rnd_buffer_size = 524288 sort_buffer_size = 8388608 join_buffer_size = 8388608</p><h4>memory table size</h4><p>tmp_table_size =67108864 max_heap_table_size=67108864</p><h4>timeout</h4><p>interactive_timeout = 1800 wait_timeout = 1800</p><h1>connect_timeout=10</h1><p>########slow query ######## slow_query_log = 1 log_slow_slave_statements = 1 log_queries_not_using_indexes = 1 log_throttle_queries_not_using_indexes = 10 long_query_time = 1</p><h1>min_examined_row_limit = 10000</h1><p>########innodb settings######## innodb_buffer_pool_size = 193273528320 innodb_buffer_pool_instances = 16 innodb_buffer_pool_dump_pct = 40 innodb_lru_scan_depth = 2048 innodb_page_cleaners = 16</p><h1>innodb_purge_threads = 4</h1><p>innodb_sort_buffer_size = 67108864</p><h1>innodb_file_per_table = 1</h1><h1>innodb_flush_log_at_trx_commit = 1</h1><p>innodb_undo_log_truncate = 1 innodb_undo_tablespaces = 3 innodb_max_undo_log_size = 2147483648 innodb_purge_rseg_truncate_frequency = 128 innodb_log_file_size = 1073741824 innodb_log_files_in_group = 3 innodb_log_buffer_size = 16777216 innodb_flush_method = O_DIRECT innodb_flush_neighbors = 0 innodb_print_all_deadlocks = 1 innodb_strict_mode = 1</p><h1>innodb_lock_wait_timeout = 50</h1><p>innodb_io_capacity = 32768 innodb_io_capacity_max = 65536 innodb_thread_concurrency = 32 innodb_write_io_threads = 8 innodb_read_io_threads = 8</p><p>########replication settings######## master_info_repository = TABLE relay_log_info_repository = TABLE gtid_mode = on enforce_gtid_consistency = 1 binlog_gtid_simple_recovery=1 relay_log_recovery = 1 slave-parallel-type = LOGICAL_CLOCK slave-parallel-workers = 16 slave_transaction_retries=128 slave_preserve_commit_order=1 log_slave_updates=1 binlog_format = ROW log_timestamps=system binlog_rows_query_log_events = 1 binlog_row_image='full' slave_skip_errors = ddl_exist_errors</p><p>########semi sync replication settings########</p><h1>plugin_dir=/data/mysql/plugin/</h1><h1>plugin_load = "rpl_semi_sync_master=semisync_master.so;rpl_semi_sync_slave=semisync_slave.so"</h1><h1>rpl_semi_sync_master_enabled = 1</h1><h1>rpl_semi_sync_master_timeout = 5000</h1><h1>rpl_semi_sync_slave_enabled = 1</h1><p>[mysqldump] quick
说明：请务必修改配置模板文件中的server-id参数，否则在配置主从复制或MHA时会报错。例如错误信息：
<code>2018-10-09T16:13:53.205115+08:00 11 [ERROR] [MY-013117] [Repl] Slave I/O for channel '': Fatal error: The slave I/O thread stops because master and slave have equal MySQL server ids; these ids must be different for replication to work (or the --replicate-same-server-id option must be used on slave but this does not always make sense; please check the manual before using it). Error_code: MY-013117</code>
- 创建目录并授权：
cd /data/mysql mkdir mysql_log chown -R mysql.mysql mysql_log/ mkdir tmp chown -R mysql.mysql tmp/
说明：有时我们可能只是从其他服务器复制MySQL的二进制文件到本地。例如，在安装MySQL 8.0时，从其他服务器复制安装文件到本地，并命名为mysql80。如下图：
此时还需要执行以下权限命令：
chmod -R 755 /data/mysql80/bin/
- 初始化MySQL：
/data/mysql57/bin/mysqld --defaults-file=/etc/my.cnf --initialize --user=mysql --basedir=/data/mysql57 --datadir=/data/mysql/data
说明：主参数--defaults-file=/etc/my.cnf必须紧接在mysqld后面，如果作为第二个或后续参数加入会报错：
<code>[ERROR] unknown variable 'defaults-file=/etc/my.cnf'！</code>
注意密码：5.7初始化后会生成一个临时密码，存在mysql.err文件中：
<code>[Note] A temporary password is generated for root@localhost: XXXXXXXX</code>
即root@localhost:后的字符串。
- 添加MySQL启动脚本到系统服务，并设置开机启动：
cp -a /data/mysql57/support-files/mysql.server /etc/init.d/mysqld
设置开机启动并检查是否成功：
chkconfig mysqld on chkconfig --list | grep mysqld
- 创建mysql软链接至/usr/bin下：
ln -s /data/mysql57/bin/mysql /usr/bin
- 启动MySQL服务：
service mysqld start
说明：如果使用的是复制文件的方式，例如前面复制的mysql80二进制文件，此处会报错：
此时还需要执行以下赋权命令：
chmod -R 755 ./mysql.server #这个文件是 /data/mysql80/support-files chmod -R 755 /etc/init.d/mysqld
- 登录MySQL，修改root密码：
mysql -uroot -pXXXXXXX
mysql> set password=password('XXXXXXX2');说明：在MySQL 8.0中使用旧方法SET PASSWORD=PASSWORD('[新密码]')会报错：
<code>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 'password('XXXXX')' at line 1</code>查看网上的相关解释为：
以前版本的MySQL的密码认证插件是“mysql_native_password”，而现在使用的是“caching_sha2_password”。
解决方案：
ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY '新密码'; FLUSH PRIVILEGES;
