MySQL 5.6和MySQL 5.7的区别

MySQL 5.6：初始化数据时需要进到家目录的 script 目录下：
执行：

/usr/local/mysql/scripts/mysql_install_db --basedir=/usr/local/mysql/
–datadir=/data/mysql --defaults-file=/etc/my.cnf --user=mysql
此时数据库密码为空。

MySQL 5.7：初始化数据时需要进到家目录的 bin 目录下

执行：

/usr/local/mysql/bin/mysqld --user=mysql --datadir=/data/mysql
–basedir=/usr/local/mysql/ --initialize
已然已经废弃了使用 mysql_install_db 这个命令进行初始化数据的操作了。

注：–initialize 会自动生成密码在 error log 里面。如果加 --initialize-insecure 密码为空。

MySQL 5.6 版本 my.cnf 和 MySQL 5.7 版本的 my.cnf
根据生产环境上测试而出的参数。其中根据真实内存去适当调整 innodb_buffer_pool 大小就可以了。（建议物理内存的50-80%）

[client]
port    = 3306
socket    = /tmp/mysql.sock
#default-character-set=utf8
[mysql]
#default-character-set=utf8
[mysqld]
port    = 3306
socket    = /tmp/mysql.sock
basedir    = /usr/local/mysql
datadir    = /data/mysql
open_files_limit    = 3072
back_log = 103
max_connections = 512
max_connect_errors = 100000
table_open_cache = 512
external-locking = FALSE
max_allowed_packet = 128M
sort_buffer_size = 2M
join_buffer_size = 2M
thread_cache_size = 51
query_cache_size = 32M
tmp_table_size = 96M
max_heap_table_size = 96M
slow_query_log = 1
slow_query_log_file = /data/mysql/slow.log
log-error = /data/mysql/error.log
long_query_time = 0.05
server-id = 1323306
log-bin = /data/mysql/mysql-bin
sync_binlog = 1
binlog_cache_size = 4M
max_binlog_cache_size = 128M
max_binlog_size = 1024M
expire_logs_days = 7
key_buffer_size = 32M
read_buffer_size = 1M
read_rnd_buffer_size = 16M
bulk_insert_buffer_size = 64M
character-set-server=utf8
default-storage-engine=InnoDB
binlog_format=row
#gtid_mode=on
#log_slave_updates=1
#enforce_gtid_consistency=1
interactive_timeout=100
wait_timeout=100
transaction_isolation = REPEATABLE-READ
innodb_additional_mem_pool_size = 16M
innodb_buffer_pool_size = 1434M
innodb_data_file_path = ibdata1:1024M:autoextend
innodb_flush_log_at_trx_commit = 1
innodb_log_buffer_size = 16M
innodb_log_file_size = 256M
innodb_log_files_in_group = 2
innodb_max_dirty_pages_pct = 50
innodb_file_per_table = 1
innodb_locks_unsafe_for_binlog = 0
[mysqldump]
quick
max_allowed_packet = 32M

MySQL 5.7 版本的参数文件：

[client]
port    = 3306
socket    = /data/mysql/mysql.sock
[mysql]
prompt="\u@db \R:\m:\s [\d]> "
no-auto-rehash
[mysqld]
user    = mysql
port    = 3306
basedir    = /usr/local/mysql
datadir    = /data/mysql/
socket    = /data/mysql/mysql.sock
character-set-server = utf8mb4
skip_name_resolve = 1
open_files_limit    = 65535
back_log = 1024
max_connections = 500
max_connect_errors = 1000000
table_open_cache = 1024
table_definition_cache = 1024
table_open_cache_instances = 64
thread_stack = 512K
external-locking = FALSE
max_allowed_packet = 32M
sort_buffer_size = 4M
join_buffer_size = 4M
thread_cache_size = 768
query_cache_size = 0
query_cache_type = 0
interactive_timeout = 600
wait_timeout = 600
tmp_table_size = 32M
max_heap_table_size = 32M
slow_query_log = 1
slow_query_log_file = /data/mysql/slow.log
log-error = /data/mysql/error.log
long_query_time = 0.1
server-id = 3306101
log-bin = /data/mysql/mysql-binlog
sync_binlog = 1
binlog_cache_size = 4M
max_binlog_cache_size = 1G
max_binlog_size = 1G
expire_logs_days = 7
gtid_mode = on
enforce_gtid_consistency = 1
log_slave_updates
binlog_format = row
relay_log_recovery = 1
relay-log-purge = 1
key_buffer_size = 32M
read_buffer_size = 8M
read_rnd_buffer_size = 4M
bulk_insert_buffer_size = 64M
lock_wait_timeout = 3600
explicit_defaults_for_timestamp = 1
innodb_thread_concurrency = 0
innodb_sync_spin_loops = 100
innodb_spin_wait_delay = 30
transaction_isolation = REPEATABLE-READ
innodb_buffer_pool_size = 1024M
innodb_buffer_pool_instances = 8
innodb_buffer_pool_load_at_startup = 1
innodb_buffer_pool_dump_at_shutdown = 1
innodb_data_file_path = ibdata1:1G:autoextend
innodb_flush_log_at_trx_commit = 1
innodb_log_buffer_size = 32M
innodb_log_file_size = 2G
innodb_log_files_in_group = 2
innodb_max_undo_log_size = 4G
innodb_io_capacity = 4000
innodb_io_capacity_max = 8000
innodb_flush_neighbors = 0
innodb_write_io_threads = 8
innodb_read_io_threads = 8
innodb_purge_threads = 4
innodb_page_cleaners = 4
innodb_open_files = 65535
innodb_max_dirty_pages_pct = 50
innodb_flush_method = O_DIRECT
innodb_lru_scan_depth = 4000
innodb_checksum_algorithm = crc32
innodb_lock_wait_timeout = 10
innodb_rollback_on_timeout = 1
innodb_print_all_deadlocks = 1
innodb_file_per_table = 1
innodb_online_alter_log_max_size = 4G
internal_tmp_disk_storage_engine = InnoDB
innodb_stats_on_metadata = 0
innodb_status_file = 1
innodb_status_output = 0
innodb_status_output_locks = 0
performance_schema = 1
performance_schema_instrument = ‘%=on’
[mysqldump]
quick
max_allowed_packet = 32M

——日志文件：

1. 错误日志 error log：对 mysql 启动，运行，关闭过程进行了记录。

2. 全量日志 general log：查询日志记录了所有对 mysql 数据库请求的信息，不论这些请求是否得到了正确的执行。

3. 二进制日志 binlog：记录了对数据库执行更改的所有操作。但是并不包括 select 和 show 这类操作。

4. 中继日志 relay log：主从同步，从库需要把主库传递过来的日志，记录到自己的 relay log 里面。

5. 慢查询日志 slow log：运行时间超过某值的所有 sql 语句都记录到慢查询日志文件中。