linux下Mysql多实例实现

什么是MySQL多实例

MySQL多实例就是在一台机器上开启多个不同的服务端口（如：3306,3307），运行多个MySQL服务进程，通过不同的socket监听不同的服务端口来提供各自的服务:；

Mysql多实例实现的3种方式

mysql 多实例常规来讲，有三种方案可以实现，这三种方案各有利弊，如下：

1、基于多配置文件

通过使用多个配置文件来启动不同的进程，以此来实现多实例。

配置文件：

[client]
port =3307
socket =/data/3307/mysql.sock
[mysql]
no-auto-rehash
[mysqld]
user = mysql
port =3307
socket =/data/3307/mysql.sock
basedir =/application/mysql
datadir =/data/3307/data
open_files_limit =1024
back_log =600
max_connections =800
max_connect_errors =3000
table_cache =614
external-locking = FALSE
max_allowed_packet =8M
sort_buffer_size =1M
join_buffer_size =1M
thread_cache_size =100
thread_concurrency =2
query_cache_size =2M
[root@web001 3307]# cat my.cnf 
[client]
port =3307
socket =/data/3307/mysql.sock
[mysql]
no-auto-rehash
[mysqld]
user = mysql
port =3307
socket =/data/3307/mysql.sock
basedir =/application/mysql
datadir =/data/3307/data
open_files_limit =1024
back_log =600
max_connections =800
max_connect_errors =3000
table_cache =614
external-locking = FALSE
max_allowed_packet =8M
sort_buffer_size =1M
join_buffer_size =1M
thread_cache_size =100
thread_concurrency =2
query_cache_size =2M
query_cache_limit =1M
query_cache_min_res_unit =2k
#default_table_type = InnoDB
thread_stack =192K
#transaction_isolation = READ-COMMITTED
tmp_table_size =2M
max_heap_table_size =2M
#long_query_time = 1
#log_long_format
#log-error = /data/3307/error.log
#log-slow-queries = /data/3307/slow.log
pid-file =/data/3307/mysql.pid
#log-bin = /data/3307/mysql-bin
relay-log =/data/3307/relay-bin
relay-log-info-file =/data/3307/relay-log.info
binlog_cache_size =1M
max_binlog_cache_size =1M
max_binlog_size =2M
expire_logs_days =7
key_buffer_size =16M
read_buffer_size =1M
read_rnd_buffer_size =1M
bulk_insert_buffer_size =1M
#myisam_sort_buffer_size = 1M
#myisam_max_sort_file_size = 10G
#myisam_max_extra_sort_file_size = 10G
#myisam_repair_threads = 1
#myisam_recover
lower_case_table_names =1
skip-name-resolve
slave-skip-errors =1032,1062
replicate-ignore-db=mysql
server-id = 7
innodb_additional_mem_pool_size =4M
innodb_buffer_pool_size =32M
innodb_data_file_path = ibdata1:128M:autoextend
innodb_file_io_threads =4
innodb_thread_concurrency =8
innodb_flush_log_at_trx_commit =2
innodb_log_buffer_size =2M
innodb_log_file_size =4M
innodb_log_files_in_group =3
innodb_max_dirty_pages_pct =90
innodb_lock_wait_timeout =120
innodb_file_per_table =0
[mysqldump]
quick
max_allowed_packet =2M
[mysqld_safe]
log-error=/data/3307/mysql_oldboy3307.err
pid-file=/data/3307/mysqld.pid

优点：逻辑简单，配置简单

缺点：管理起来不方便

mysql启动停止脚本。

#！/bin/sh

#init

port=3307
mysql_user="root"
mysql_pwd="111111"
CmdPath="/application/mysql/bin"
mysql_sock="/data/${port}/mysql.sock"

function_start_mysql()
{
        if [ ! -e "$mysql_sock" ];then
                printf "Starting MySql...
"
                /bin/sh ${CmdPath}/mysqld_safe --defaults-file=/data/${port}/my.cnf 2>&1 >/dev/null &

        else
                printf "Mysql is running...
"
                exit
        fi
}

#stop function
function_stop_mysql()
{
        if [ ! -e "$mysql_sock" ];then
                printf "MySql is stopped...
"
                exit
        else
                printf "Stoping MySQL...
"
                ${CmdPath}/mysqladmin -u ${mysql_user} -p${mysql_pwd} -S /data/${port}/mysql.sock shutdown
        fi
}

#restart function
function_restart_mysql()
{
        printf "Restarting Mysql...
"
        function_stop_mysql
        sleep 2
        function_start_mysql

}

case $1 in
start)
        function_start_mysql
;;
stop)
        function_stop_mysql
;;
restart)
        function_restart_mysql
;;
*)
        printf "Usage /data/${port}/mysql {start|stop|restart}
"
;;
esac 

2、基于mysqld_multi

通过官方自带的 mysqld_multi 工具，使用单独配置文件来实现多实例

优点： 便于集中管理管理

缺点： 不方便针对每个实例配置进行定制

3、基于IM

使用 MySQL 实例管理器（MYSQLMANAGER），这个方法好像比较好不过也有点复杂

优点：便于集中管理

缺点：耦合度高。IM一挂，实例全挂

不方便针对每个实例配置进行定制