本次升级采用：out of place 逻辑升级方式：

基本步骤：

①：停止业务，备份现有数据库(mysqldump方式或者物理备份)

②：下载MySQL5.7.18软件包，然后安装到别的目录，

③：修改配置my.cnf配置文件，指定basedir为新的软件目录

④：启动新版本数据库，然后执行mysql_upgrade -uroot -p 升级数据库；

⑤：升级完成，重启数据库

⑥：检查升级结果：select version();

升级MySQL检查：

①：现有MySQL数据库是否已经备份

②：业务是否已经停止

1、检查现有环境：

①：检查MySQL状态：

[mysql@db2 ~]$ ps -ef | grep mysql

mysql     1806     1  0 14:36 ?        00:00:00 /bin/sh /mysql/bin/mysqld_safe --defaults-file=/mysql/my.cnf

mysql     1868  1806  0 14:36 ?        00:00:00 /mysql/bin/mysqld --defaults-file=/mysql/my.cnf --basedir=/mysql --datadir=/mysql/data --plugin-dir=/mysql/lib/plugin --log-error=/mysql/data/db2.err --pid-file=/mysql/data/db2.pid

②：查看现有配置文件

[mysql@db2 ~]$ vim /mysql/my.cnf

[mysql]

no_auto_rehash

default_character_set     = utf8

socket                    = /mysql/data/mysql.sock

[client]

default_character_set     = utf8

[mysqld]

server_id                 = 1607

port                      = 3306

basedir                   = /mysql/

datadir                   = /mysql/data/

socket                    = /mysql/data/mysql.sock

pid_file                  = /mysql/data/mysql.pid

log_error                 = /mysql/data/mysql_error.log

log_bin                   = /mysql/data/mysql_bin

relay_log                 = /mysql/data/relay_bin

character_set_server      = utf8

collation_server          = utf8_general_ci

innodb_buffer_pool_size   = 8G

innodb_buffer_pool_instances = 8

innodb_log_file_size      = 1G

innodb_log_files_in_group = 3

innodb_log_buffer_size    = 24M

innodb_flush_log_at_trx_commit = 1

innodb_file_per_table     = 1

innodb_flush_method       = O_DIRECT

innodb_io_capacity        = 200

innodb_io_capacity_max    = 600

innodb_thread_concurrency = 0

innodb_autoinc_lock_mode  = 2

innodb_lock_wait_timeout  = 60

innodb_read_io_threads    = 4

innodb_write_io_threads   = 4

innodb_max_dirty_pages_pct = 80

innodb_autoextend_increment = 512

innodb_checksum_algorithm = NONE

innodb_doublewrite        = 0

innodb_use_native_aio     = 1

innodb_open_files         = 8192

sync_binlog               = 1

sync_relay_log            = 1

relay_log_info_repository = TABLE

master_info_repository    = TABLE

expire_logs_days          = 10

binlog_format             = ROW

transaction-isolation     = READ-COMMITTED

concurrent_insert         = 2

skip_slave_start          = TRUE

back_log                  = 2000

thread_stack              = 256k

thread_cache_size         = 256

key_buffer_size           = 256M

tmp_table_size            = 64M

read_buffer_size          = 2M

read_rnd_buffer_size      = 8M

sort_buffer_size          = 2M

join_buffer_size          = 2M

query_cache_size          = 0

query_cache_type          = 0

max_heap_table_size       = 64M

binlog_cache_size         = 2M

table_open_cache          = 8192

max_allowed_packet        = 64M

bulk_insert_buffer_size   = 64M

max_connect_errors        = 100000

max_connections           = 500

connect_timeout           = 300

wait_timeout              = 86400

interactive_timeout       = 86400

lower_case_table_names    = 1

open_files_limit          = 20480

skip_name_resolve

skip_external_locking

explicit_defaults_for_timestamp = TRUE

sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES

③：检查现有MySQL的版本信息：

[mysql@db2 ~]$ mysql -u root -p

Enter password:

Welcome to the MySQL monitor.  Commands end with ; or \g.

Your MySQL connection id is 6

Server version: 5.6.30 Source distribution

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> \s

--------------

mysql  Ver 14.14 Distrib 5.6.30, for Linux (x86_64) using  EditLine wrapper

Connection id:          6

Current database:

Current user:           root@localhost

SSL:                    Not in use

Current pager:          stdout

Using outfile:          ''

Using delimiter:        ;

Server version:         5.6.30 Source distribution

Protocol version:       10

Connection:             Localhost via UNIX socket

Server characterset:    latin1

Db     characterset:    latin1

Client characterset:    utf8

Conn.  characterset:    utf8

UNIX socket:            /tmp/mysql.sock

Uptime:                 5 min 32 sec

Threads: 1  Questions: 18  Slow queries: 0  Opens: 67  Flush tables: 1  Open tables: 60  Queries per second avg: 0.054

--------------

mysql> select version();

+-----------+

| version() |

+-----------+

| 5.6.30    |

+-----------+

1 row in set (0.01 sec)

mysql>

④：关闭数据库：

[mysql@db2 ~]$ mysql -u root -p --execute="SET GLOBAL innodb_fast_shutdown=0"

Enter password:

[mysql@db2 ~]$ mysql -u root -p --execute="show global variables like 'innodb_fast_shutdown'"

Enter password:

+----------------------+-------+

| Variable_name        | Value |

+----------------------+-------+

| innodb_fast_shutdown | 0     |

+----------------------+-------+

[mysql@db2 ~]$ mysqladmin -uroot -p shutdown

Enter password:

注意：innodb_fast_shutdown参数解释：

关闭：innodb_fast_shutdown=

0 ：完成所有的full purge和merge insert buffer操作(如：做InnoDB plugin升级时)

1 ：默认，不需要完成上述操作，但会刷新缓冲池中的脏页

2 ：不完成上述两个操作，而是将日志写入日志文件，下次启动时，会执行恢复操作recovery

没有正常地关闭数据库(如：kill命令)/innodb_fast_shutdown=2时，需要进行恢复操作。

2、下载mysql5.7.18,并且解压到新目录

mysql-5.7.18-linux-glibc2.5-x86_64.tar.gz     (这个软件包解压后就可以用，不用安装)

[mysql@db2 ~]$ tar zxvf mysql-5.7.18-linux-glibc2.5-x86_64.tar.gz   (把软件直接解压到/home/mysql)

[mysql@db2 ~]$ mv mysql-5.7.18-linux-glibc2.5-x86_64/    mysql5718   (mysql5718这个就是新的软件目录)

3、修改配置文件：my.cnf

[mysql@db2 mysql5718]$ cp /mysql/my.cnf ./

[mysql@db2 mysql5718]$ vim my.cnf

basedir                   = /home/mysql/mysql5718/     -----只需要修改这一行就可以，指向新目录

4、使用新软件启动MySQL数据库：

[mysql@db2 mysql5718]$ /home/mysql/mysql5718/bin/mysqld_safe --defaults-file=/home/mysql/mysql5718/my.cnf --socket=/mysql/data/mysql.sock &

5、升级MySQL：

[mysql@db2 mysql5718]$/home/mysql/mysql5718/bin/mysql_upgrade -uroot -p--socket=/mysql/data/mysql.sock

Enter password:

Checking if update is needed.

Checking server version.

Running queries to upgrade MySQL server.

Checking system database.

mysql.columns_priv                                 OK

mysql.db                                           OK

mysql.engine_cost                                  OK

mysql.event                                        OK

mysql.func                                         OK

mysql.general_log                                  OK

mysql.gtid_executed                                OK

mysql.help_category                                OK

mysql.help_keyword                                 OK

mysql.help_relation                                OK

mysql.help_topic                                   OK

mysql.innodb_index_stats                           OK

mysql.innodb_table_stats                           OK

mysql.ndb_binlog_index                             OK

mysql.plugin                                       OK

mysql.proc                                         OK

mysql.procs_priv                                   OK

mysql.proxies_priv                                 OK

mysql.server_cost                                  OK

mysql.servers                                      OK

mysql.slave_master_info                            OK

mysql.slave_relay_log_info                         OK

mysql.slave_worker_info                            OK

mysql.slow_log                                     OK

mysql.tables_priv                                  OK

mysql.time_zone                                    OK

mysql.time_zone_leap_second                        OK

mysql.time_zone_name                               OK

mysql.time_zone_transition                         OK

mysql.time_zone_transition_type                    OK

mysql.user                                         OK

Upgrading the sys schema.

Checking databases.

sys.sys_config                                     OK

Upgrade process completed successfully.

Checking if update is needed.

出现上述信息，就表明MySQL升级完成了；

6、升级完成后，重启数据库

[mysql@db2 mysql5718]$ /home/mysql/mysql5718/bin/mysqladmin shutdown -u root -p

[mysql@db2 mysql5718]$ /home/mysql/mysql5718/bin/mysqld_safe --defaults-file=/home/mysql/mysql5718/my.cnf --socket=/mysql/data/mysql.sock &

7、登录数据库检查升级状态：

[mysql@db2 bin]$ mysql -u root -p

Enter password:

ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2)

有时候我们登录MySQL的时候会出现上面的错误，可是我们已经在配置文件指定了mysql.sock的目录呀，为什么还去找别的目录呢，解决方法有两种：

第一在my.cnf配置文件添加下面的信息：(有时候不管用，比如我们上面的配置文件已经添加了可是还是报错)

[mysql]

socket                    = /mysql/data/mysql.sock

第二种：我们做个软连接到tmp下就可以了：

[mysql@db2 bin]$ ln -s /mysql/data/mysql.sock /tmp/mysql.sock

做完软连接后，我们再等了数据库就OK了：

[mysql@db2 bin]$ mysql -u root -p

Enter password:

Welcome to the MySQL monitor.  Commands end with ; or \g.

Your MySQL connection id is 3

Server version: 5.7.18-log MySQL Community Server (GPL)

Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its

affiliates. Other names may be trademarks of their respective

owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> \s

--------------

mysql  Ver 14.14 Distrib 5.6.30, for Linux (x86_64) using  EditLine wrapper

Connection id:          3

Current database:

Current user:           root@localhost

SSL:                    Not in use

Current pager:          stdout

Using outfile:          ''

Using delimiter:        ;

Server version:         5.7.18-log 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/mysql.sock

Uptime:                 4 min 16 sec

Threads: 1  Questions: 6  Slow queries: 0  Opens: 110  Flush tables: 1  Open tables: 25  Queries per second avg: 0.023

--------------

mysql> select version();

+------------+

| version()  |

+------------+

| 5.7.18-log |

+------------+

1 row in set (0.39 sec)

mysql>

######################################################################

知识扩展：

关闭：innodb_fast_shutdown=

0 ：完成所有的full purge和merge insert buffer操作(如：做InnoDB plugin升级时)

1 ：默认，不需要完成上述操作，但会刷新缓冲池中的脏页

2 ：不完成上述两个操作，而是将日志写入日志文件，下次启动时，会执行恢复操作recovery

没有正常地关闭数据库(如：kill命令)/innodb_fast_shutdown=2时，需要进行恢复操作。

恢复：innodb_force_recovery=

0 ：默认，但需要恢复时执行所有恢复操作

1 ：忽略检查到的corrupt页

2 ：阻止主线程的运行，如主线程需要执行full purge操作，会导致crash

3 ：不执行事务回滚操作

4 ：不执行插入缓冲的合并操作

5 ：不查看撤销日志undo log，InnoDB存储引擎会将所有未提交的事务视为已提交

6 ：不执行前滚的操作