前言
防止单点故障，虽然有master/master, master/slave 等架构，但是仅仅这样，在实际应用中，还是有诸多考虑。
再则，现如今一个企业为了节约成本，除了核心稳定无赖外，更多的考虑开源数据库，通过第三方软件，实现HA 架构。
话，不多说，说正事：
MMM (Master-Master Replication Manager for MySQL) is a set of flexible scripts to per-
form monitoring/failover and management of MySQL Master-Master replication configura-
tions (with only one node writable at any time). The toolset also has the ability to read
balance standard master/slave configurations with any number of slaves, so you can use it to
move virtual IP addresses around a group of servers depending on whether they are behind
in replication. In addition to that, it also has scripts for data backups, resynchronization
between nodes etc.
mmm_mond monitoring daemon which does all monitoring work and makes all decisions
about roles moving and so on.
mmm_agentd agent daemon which runs on each MySQL server and provides monitoring node
with simple set of remote services.
mmm_control
simple script dedicated to management of the mmm mond processes by com-
mands.
Requirements
For an MMM setup with n MySQL servers, you’ll need
n + 1 hosts
One host for each MySQL server; one host for the MMM monitor.
2 * (n + 1) IPs
One IP for each host (see above); one IP for the writer role; n IPs for one reader role per host.
monitor user
A MySQL user with privileges REPLICATION CLIENT for MMM monitor.
agent user
A MySQL user with privileges SUPER, REPLICATION CLIENT, PROCESS for MMM agent.
replication user
A MySQL user with privileges REPLICATION SLAVE used for replication.
tools user
A MySQL user with privileges SUPER, REPLICATION CLIENT, RELOAD for MMM tools.
Requirements - monitoring host
perl with ithreads support
• fping (if you want to run mmm_mond as non-root user)
• Perl modules:
− Algorithm::Diff
− Class:Singleton
− DBI and DBD::mysql
− File::Basename
− File::stat
− File::Temp
− Log::Dispatch
− Log::Log4perl
− Mail::Send
− Net::Ping
− Proc::Daemon
− Thread::Queue
− Time::HiRes
环境： Redhat 6.4 x86 64bit , Mysql 5.7.21
mmm 下载地址：
http://mysql-mmm.org/doku.php
1, 配置 yum 源：
配置局域网yum源：
[root@martin01 ~]# cat /etc/exports
/data/YUM *(ro)
[root@martin01 ~]# /etc/init.d/nfs restart
[root@martin01 ~]# /etc/init.d/portreserve restart
showmount -e 10.20.30.41
其他节点： /etc/init.d/nfs restart
showmount -e 10.20.30.41
mount 10.20.30.41:/data/YUM /mnt/
安装 rpm 包（我这里已经安装过oracle数据库，大部分的rpm 包已包含）：
yum install -y perl-*
yum install -y libart_lgpl.x86_64
yum install -y rrdtool.x86_64
yum install -y rrdtool-perl.x86_64
yum install -y binutils* compat-libstdc++ elfutils-libelf elfutils-libelf-devel elfutils-libelf-devel-static gcc gcc-c++ glibc glibc-common glibc-devel glibc-headers kernel-headers ksh libaio libaio-devel libgcc libgomp libstdc++ libstdc++-devel make sysstat unixODBC unixODBC-devel binutils-* compat-* gcc-*
2， 创建mysql 用户及素组：
groupadd -g 1200 mysql
useradd -m -g 1201 mysql mysql
mkdir -pv /dba/mysql/data /dba/mysql/logfile
3, 关闭iptables selinux
4,
配置NTP ，同步时间
yum -y install ntpvi /etc/ntp.conf增加3个时间服务器server s2d.time.edu.cn iburst #西南地区网络中心server s2e.time.edu.cn iburst #西北地区网络中心server s2f.time.edu.cn iburst #东北地区网络中心启动ntp服务 systemctl start ntpd systemctl enable ntpd 查看状态ntpq -p
5, 安装Mysql 数据库 （主主复制）
在MySQL的主配置文件中修改/添加如下内容：
Server-1上：
[mysqld]
server-id = 10
log-bin = mysql-bin
replicate-do-db = mydb
auto-increment-increment = 2
auto-increment-offset = 1
# service mysqld restart
Server-2上
：
[mysqld]
server-id = 20
log-bin = mysql-bin
replicate-do-db = mydb
auto-increment-increment = 2
auto-increment-offset = 2
# service mysqld restart
主1；
(root@(none)) Mysql >flush tables with read lock;
Query OK, 0 rows affected (0.00 sec)
(root@(none)) Mysql >show master status;
+-----------------+----------+--------------+------------------+---------------------------------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+-----------------+----------+--------------+------------------+---------------------------------------------+
| bin_3308.000008 | 194 | | | d6bcd601-f065-11e6-8e79-080027e19201:1-2238 |
+-----------------+----------+--------------+------------------+---------------------------------------------+
1 row in set (0.00 sec)
(root@(none)) Mysql >UNLOCK TABLES;
Query OK, 0 rows affected (0.00 sec)
--my.cnf : (主主）
[root@martin03 ~]# cat /etc/my.cnf
[mysqld]
basedir=/usr/local/mysql-5.7.16
datadir=/data/mysqldata
port=3308
server_id=3
########log settings########
slow_query_log = 1
log_error = /data/mysqllog/error_3308.log
slow_query_log_file = /data/mysqllog/slow_3308.log
log_queries_not_using_indexes = 1
log_slow_admin_statements = 1
log_slow_slave_statements = 1
log_throttle_queries_not_using_indexes = 10
expire_logs_days = 20
long_query_time = 2
min_examined_row_limit = 100
#########replication settings########
master_info_repository = TABLE
relay_log_info_repository = TABLE
log_bin = /data/mysqllog/bin_3308.log
sync_binlog = 1
#gtid_mode = on
#enforce_gtid_consistency = 1
log_slave_updates
binlog_format = row
relay_log = relay.log
relay_log_recovery = 1
#binlog_gtid_simple_recovery = 1
slave_skip_errors = ddl_exist_errors
replicate_ignore_db=information_schema,performance_schema,sys
auto_increment_increment = 2
auto_increment_offset = 2
skip_name_resolve
########innodb settings########
innodb_page_size = 16384
innodb_buffer_pool_size = 2G
innodb_buffer_pool_instances = 8
innodb_buffer_pool_load_at_startup = 1
innodb_buffer_pool_dump_at_shutdown = 1
innodb_lru_scan_depth = 2000
innodb_lock_wait_timeout = 5
innodb_io_capacity = 4000
innodb_io_capacity_max = 8000
innodb_flush_method = O_DIRECT
innodb_file_format = Barracuda
innodb_file_format_max = Barracuda
innodb_undo_logs = 56
innodb_flush_neighbors = 1
innodb_log_file_size = 2G
innodb_log_buffer_size = 8M
innodb_purge_threads = 4
innodb_large_prefix = 1
innodb_thread_concurrency = 64
innodb_print_all_deadlocks = 1
innodb_strict_mode = 1
innodb_sort_buffer_size = 67108864
sql_mode="STRICT_TRANS_TABLES,NO_ENGINE_SUBSTITUTION,NO_ZERO_DATE,NO_ZERO_IN_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER"
--Base test db
--主1
(root@(none)) Mysql >change master to
-> master_host='10.20.30.43',
-> master_user='replicate',
-> master_password='replicate123',
-> master_log_file='bin_3308.000002',
-> master_log_pos=145447,
-> master_port=3308;
Query OK, 0 rows affected, 2 warnings (0.06 sec)
--主2
(root@(none)) Mysql >change master to
-> master_host='10.20.30.42',
-> master_user='replicate',
-> master_password='replicate123',
-> master_log_file='bin_3308.000008',
-> master_log_pos=194,
-> master_port=3308;
Query OK, 0 rows affected, 2 warnings (0.07 sec)
主1，主2；
(root@(none)) Mysql >START SLAVE;
Query OK, 0 rows affected (0.01 sec)
主1，主2；
(root@(none)) Mysql >show slave status\G;
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 10.20.30.42
Master_User: replicate
Master_Port: 3308
Connect_Retry: 60
Master_Log_File: bin_3308.000008
Read_Master_Log_Pos: 194
Relay_Log_File: relay.000002
Relay_Log_Pos: 319
Relay_Master_Log_File: bin_3308.000008
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Replicate_Do_DB:
Replicate_Ignore_DB: information_schema,performance_schema,sys
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno: 0
Last_Error:
Skip_Counter: 0
Exec_Master_Log_Pos: 194
Relay_Log_Space: 516
Until_Condition: None
Until_Log_File:
Until_Log_Pos: 0
Master_SSL_Allowed: No
Master_SSL_CA_File:
Master_SSL_CA_Path:
Master_SSL_Cert:
Master_SSL_Cipher:
Master_SSL_Key:
Seconds_Behind_Master: 0
Master_SSL_Verify_Server_Cert: No
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 0
Last_SQL_Error:
Replicate_Ignore_Server_Ids:
Master_Server_Id: 2
Master_UUID: d6bcd601-f065-11e6-8e79-080027e19201
Master_Info_File: mysql.slave_master_info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
Master_Retry_Count: 86400
Master_Bind:
Last_IO_Error_Timestamp:
Last_SQL_Error_Timestamp:
Master_SSL_Crl:
Master_SSL_Crlpath:
Retrieved_Gtid_Set:
Executed_Gtid_Set: 3dc1a784-f5c6-11e6-8a3d-080027e19201:1-5
Auto_Position: 0
Replicate_Rewrite_DB:
Channel_Name:
Master_TLS_Version:
1 row in set (0.00 sec)
--
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
---约---
MMM配置：
mmm_monitor : 10.20.30.41
mysql_master1 : 10.20.30.42 --write
mysql_master2 : 10.20.30.43 --write
mysql_slave1 : 10.20.30.41 --read
port : 3308
write_vip 10.20.30.50 （master2）
read_vip 10.20.30.51/52 (master1/slave1)
1, /etc/hosts 配置：
[root@martin01 ~]# cat /etc/hosts
127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4
::1 localhost localhost.localdomain localhost6 localhost6.localdomain6
## --Mysql-- ##
10.20.30.41 martin01
10.20.30.42 martin02
10.20.30.43 martin03
---到时mmm 配置解析时，很重要（主机名最好标准化）
新建同步数据库需要的用户
使用mysql-mmm时一共需要三个用户: replication、mmm_agent和mmm_monitor（管理服务器上用来监控cluster状态的用户，所以可以限定只能从管理服务器登录）。使用下面三条命令新建这三个用户并分配相应的权限
所有的mysql 服务器都运行一遍
(root@(none)) Mysql > grant replication slave on *.* to 'replicate'@'10.20.30.%' identified by 'replicate123';
(root@(none)) Mysql >GRANT SUPER, REPLICATION CLIENT, PROCESS ON *.* TO'mmm_monitor'@'10.20.30.%' identified by 'mmm_monitor123';
Query OK, 0 rows affected, 1 warning (0.01 sec)
(root@(none)) Mysql >GRANT SUPER, REPLICATION CLIENT, PROCESS ON *.* TO'mmm_agent'@'10.20.30.%' identified by 'mmm_agent123';
Query OK, 0 rows affected, 1 warning (0.01 sec)
(root@(none)) Mysql >flush privileges;
Query OK, 0 rows affected (0.00 sec)
2， 安装mmm :
[root@martin01 local]# tar -xvf mysql-mmm-2.2.1 -C /usr/local/
[root@martin01 local]# cd mysql-mmm-2.2.1/
[root@martin01 mysql-mmm-2.2.1]# ls
bin COPYING etc INSTALL lib Makefile README sbin UPGRADE VERSION
[root@martin01 mysql-mmm-2.2.1]# make install
mkdir -p /usr/share/perl5/vendor_perl/MMM /usr/lib/mysql-mmm /usr/sbin /var/log/mysql-mmm /etc /etc/mysql-mmm /etc/init.d/
cp -r lib/Common/ /usr/share/perl5/vendor_perl/MMM
[ -f /etc/mysql-mmm/mmm_common.conf ] || cp etc/mysql-mmm/mmm_common.conf /etc/mysql-mmm/
mkdir -p /usr/lib/mysql-mmm/agent/
cp -r lib/Agent/ /usr/share/perl5/vendor_perl/MMM
cp -r bin/agent/* /usr/lib/mysql-mmm/agent/
cp -r etc/init.d/mysql-mmm-agent /etc/init.d/
cp sbin/mmm_agentd /usr/sbin
[ -f /etc/mysql-mmm/mmm_agent.conf ] || cp etc/mysql-mmm/mmm_agent.conf /etc/mysql-mmm/
mkdir -p /usr/lib/mysql-mmm/monitor/
cp -r lib/Monitor/ /usr/share/perl5/vendor_perl/MMM
cp -r bin/monitor/* /usr/lib/mysql-mmm/monitor/
cp -r etc/init.d/mysql-mmm-monitor /etc/init.d/
cp sbin/mmm_control sbin/mmm_mond /usr/sbin
[ -f /etc/mysql-mmm/mmm_mon.conf ] || cp etc/mysql-mmm/mmm_mon.conf /etc/mysql-mmm/
mkdir -p /usr/lib/mysql-mmm/tools/
cp -r lib/Tools/ /usr/share/perl5/vendor_perl/MMM
cp -r bin/tools/* /usr/lib/mysql-mmm/tools/
cp sbin/mmm_backup sbin/mmm_clone sbin/mmm_restore /usr/sbin
[ -f /etc/mysql-mmm/mmm_tools.conf ] || cp etc/mysql-mmm/mmm_tools.conf /etc/mysql-mmm/
[root@martin01 mysql-mmm]# pwd
/etc/mysql-mmm
3， 配置mmm 配置文件：
[root@martin01 ~]# ll /etc/mysql-mmm/mmm_*
-rw-r----- 1 root root 39 Mar 9 17:13 /etc/mysql-mmm/mmm_agent.conf
-rw-r----- 1 root root 769 Mar 9 17:09 /etc/mysql-mmm/mmm_common.conf
-rw-r----- 1 root root 410 Mar 9 16:34 /etc/mysql-mmm/mmm_mon.conf
-rw-r----- 1 root root 1293 Feb 19 13:28 /etc/mysql-mmm/mmm_tools.conf
mmm_common.conf 所有节点 配置参数一样：
mmm_mon.conf 所有节点 配置参数一样：
mmm_agent.conf 各节点自己信息（主机名）：
[root@martin01 mysql-mmm]# cat mmm_common.conf
active_master_role writer
<host default>
cluster_interface
eth0
agent_port 9989
mysql_port 3308
--不写，默认为3306,启动会连接失败
pid_path /var/run/mmm_agentd.pid
bin_path /usr/lib/mysql-mmm/
replication_user replicate
replication_password replicate123
agent_user mmm_agent
agent_password mmm_agent123
</host>
<host martin03>
ip 10.20.30.43
--master2
mode master
peer martin02
--master1
</host>
<host martin02>
ip 10.20.30.42
--master1
mode master
peer martin03
--master2
</host>
<host martin01>
ip 10.20.30.41 --salve
mode slave
</host>
<role writer>
hosts martin03,martin02
ips 10.20.30.50
--vip_write
mode exclusive
</role>
<role reader>
hosts martin03,martin02,martin01
ips 10.20.30.51,10.20.30.52
--vip_read
mode balanced
</role>
[root@martin01 mysql-mmm]# cat mmm_agent.conf --各节点自己信息（主机名）
include mmm_common.conf
this martin01
[root@martin01 mysql-mmm]# cat mmm_mon.conf
include mmm_common.conf
<monitor>
ip 127.0.0.1
port 9988
pid_path /var/run/mmm_mond.pid
bin_path /usr/lib/mysql-mmm/
status_path /var/lib/misc/mmm_mond.status
ping_ips 10.20.30.42,10.20.30.43,10.20.30.41
auto_set_online 10
mode active
wait_for_other_master 120
</monitor>
<host default>
monitor_user mmm_monitor
monitor_password mmm_monitor123
</host>
debug 1
--------------------------------------------------------
启动：
自动启动agent 和 monitor
a. 在monitor上启动 monitor
b. 在所有数据库服务器上启动 agent
c, MMM启动顺序：先启动monitor，再启动 agent
# /etc/init.d/mysql-mmm-monitor restart & --monitor
#[root@martin03 ~]# /etc/init.d/mysql-mmm-agent restart &
[1] 2894
[root@martin03 ~]# Daemon bin: '/usr/sbin/mmm_agentd'
Daemon pid: '/var/run/mmm_agentd.pid'
Daemon bin: '/usr/sbin/mmm_agentd'
Daemon pid: '/var/run/mmm_agentd.pid'
Shutting down MMM Agent daemon not running.
Daemon bin: '/usr/sbin/mmm_agentd'
Daemon pid: '/var/run/mmm_agentd.pid'
Starting MMM Agent daemon... Ok
[1]+ Done /etc/init.d/mysql-mmm-agent restart
检测， 监控日志：
[root@martin03 mysql-mmm]# pwd
/var/log/mysql-mmm
[root@martin03 mysql-mmm]# ll
total 52
-rw-r--r-- 1 root root 2954 Mar 9 21:11 mmm_agentd.log
-rw-r--r-- 1 root root 45015 Mar 9 21:11 mmm_mond.log
--master 2
[root@martin03 ~]# mmm_control show
martin01(10.20.30.41) slave/ONLINE. Roles: reader(10.20.30.51)
martin02(10.20.30.42) master/ONLINE. Roles: reader(10.20.30.52)
martin03(10.20.30.43) master/ONLINE. Roles: writer(10.20.30.50)
[root@martin03 ~]# mmm_control checks all
martin02 ping [last change: 2017/03/09 21:10:51] OK
martin02 mysql [last change: 2017/03/09 21:10:51] OK
martin02 rep_threads [last change: 2017/03/09 21:10:51] OK
martin02 rep_backlog [last change: 2017/03/09 21:10:51] OK: Backlog is null
martin03 ping [last change: 2017/03/09 21:10:51] OK
martin03 mysql [last change: 2017/03/09 21:10:51] OK
martin03 rep_threads [last change: 2017/03/09 21:10:51] OK
martin03 rep_backlog [last change: 2017/03/09 21:10:51] OK: Backlog is null
martin01 ping [last change: 2017/03/09 21:10:51] OK
martin01 mysql [last change: 2017/03/09 21:10:51] OK
martin01 rep_threads [last change: 2017/03/09 21:10:51] OK
martin01 rep_backlog [last change: 2017/03/09 21:10:51] OK: Backlog is null
[root@martin03 ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 08:00:27:e1:92:01 brd ff:ff:ff:ff:ff:ff
inet 10.20.30.43/24 brd 10.20.30.255 scope global eth0
inet 10.20.30.50/32 scope global eth0
inet6 fe80::a00:27ff:fee1:9201/64 scope link tentative dadfailed
valid_lft forever preferred_lft forever
--master 1 :
[root@martin02 ~]# mmm_control show
martin01(10.20.30.41) slave/ONLINE. Roles: reader(10.20.30.51)
martin02(10.20.30.42) master/ONLINE. Roles: reader(10.20.30.52)
martin03(10.20.30.43) master/ONLINE. Roles: writer(10.20.30.50)
[root@martin02 ~]# mmm_control checks all
martin02 ping [last change: 2017/03/09 21:10:56] OK
martin02 mysql [last change: 2017/03/09 21:10:56] OK
martin02 rep_threads [last change: 2017/03/09 21:10:56] OK
martin02 rep_backlog [last change: 2017/03/09 21:10:56] OK: Backlog is null
martin03 ping [last change: 2017/03/09 21:10:56] OK
martin03 mysql [last change: 2017/03/09 21:10:56] OK
martin03 rep_threads [last change: 2017/03/09 21:10:56] OK
martin03 rep_backlog [last change: 2017/03/09 21:10:56] OK: Backlog is null
martin01 ping [last change: 2017/03/09 21:10:56] OK
martin01 mysql [last change: 2017/03/09 21:10:56] OK
martin01 rep_threads [last change: 2017/03/09 21:10:56] OK
martin01 rep_backlog [last change: 2017/03/09 21:10:56] OK: Backlog is null
[root@martin02 ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 08:00:27:e1:92:01 brd ff:ff:ff:ff:ff:ff
inet 10.20.30.42/24 brd 10.20.30.255 scope global eth0
inet 10.20.30.52/32 scope global eth0
inet6 fe80::a00:27ff:fee1:9201/64 scope link tentative dadfailed
valid_lft forever preferred_lft forever
--slave
[root@martin01 mysql-mmm]# mmm_control show
martin01(10.20.30.41) slave/ONLINE. Roles: reader(10.20.30.51)
martin02(10.20.30.42) master/ONLINE. Roles: reader(10.20.30.52)
martin03(10.20.30.43) master/ONLINE. Roles: writer(10.20.30.50)
[root@martin01 mysql-mmm]# mmm_control checks all
martin02 ping [last change: 2017/03/09 21:10:58] OK
martin02 mysql [last change: 2017/03/09 21:10:58] OK
martin02 rep_threads [last change: 2017/03/09 21:10:58] OK
martin02 rep_backlog [last change: 2017/03/09 21:10:58] OK: Backlog is null
martin03 ping [last change: 2017/03/09 21:10:58] OK
martin03 mysql [last change: 2017/03/09 21:10:58] OK
martin03 rep_threads [last change: 2017/03/09 21:10:58] OK
martin03 rep_backlog [last change: 2017/03/09 21:10:58] OK: Backlog is null
martin01 ping [last change: 2017/03/09 21:10:58] OK
martin01 mysql [last change: 2017/03/09 21:10:58] OK
martin01 rep_threads [last change: 2017/03/09 21:10:58] OK
martin01 rep_backlog [last change: 2017/03/09 21:10:58] OK: Backlog is null
[root@martin01 mysql-mmm]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 08:00:27:e1:92:01 brd ff:ff:ff:ff:ff:ff
inet 10.20.30.41/24 brd 10.20.30.255 scope global eth0
inet 10.20.30.51/32 scope global eth0
inet6 fe80::a00:27ff:fee1:9201/64 scope link
valid_lft forever preferred_lft forever
[root@martin01 mysql-mmm]# mmm_control ping
OK: Pinged successfully!
[root@martin02 ~]# mmm_control mode
ACTIVE
[root@martin01 mysql-mmm]# mmm_control help
Valid commands are:
help - show this message
ping - ping monitor
show - show status
checks [<host>|all [<check>|all]] - show checks status
set_online <host> - set host <host> online
set_offline <host> - set host <host> offline
mode - print current mode.
set_active - switch into active mode.
set_manual - switch into manual mode.
set_passive - switch into passive mode.
move_role [--force] <role> <host> - move exclusive role <role> to host <host>
(Only use --force if you know what you are doing!)
set_ip <ip> <host> - set role with ip <ip> to host <host>
连接测试：
------------------------------------ The End --------------------------------
备准： 在实际安装过程中less and more 出现很多问题， 以下为问题解决方法：
1， 配置完成后， 直接通过启动 monitor,或 agend 时 报错：
[root@martin02 ~]# /usr/local/mysql-mmm-2.2.1/etc/init.d/mysql-mmm-agent start
Daemon bin: '/usr/sbin/mmm_agentd'
Daemon pid: '/var/run/mmm_agentd.pid'
Starting MMM Agent daemon... Can't locate Proc/Daemon.pm in @INC (@INC contains: /usr/local/lib64/perl5 /usr/local/share/perl5 /usr/lib64/perl5/vendor_perl /usr/share/perl5/vendor_perl /usr/lib64/perl5 /usr/share/perl5 .) at /usr/sbin/mmm_agentd line 7.
BEGIN failed--compilation aborted at /usr/sbin/mmm_agentd line 7.
failed
解决方法：
--解决方案：
[root@oracle ~]# cpan Proc::Daemon
[root@oracle ~]# cpan Log::Log4perl
yum install -y perl-*
yum install -y libart_lgpl.x86_64
yum install -y mysql-mmm.noarch fail
yum install -y rrdtool.x86_64
yum install -y rrdtool-perl.x86_64
通过设置网关，/etc/resolve.conf 配置后。通过网络下载：
---another way to install lib package in network
cpan -i Algorithm::Diff Class::Singleton DBI DBD::mysql Log::Dispatch Log::Log4perl Mail::Send Net::Ping Proc::Daemon Time::HiRes Params::Validate Net::ARP
----------
[root@martin03 ~]# ping www.baidu.com
PING www.a.shifen.com (14.215.177.38) 56(84) bytes of data.
64 bytes from 14.215.177.38: icmp_seq=1 ttl=56 time=33.4 ms
[root@martin03 ~]# cpan -i Algorithm::Diff Class::Singleton DBI DBD::mysql Log::Dispatch Log::Log4perl Mail::Send Net::Ping Proc::Daemon Time::HiRes Params::Validate Net::ARP
CPAN: Storable loaded ok (v2.20)
CPAN: LWP::UserAgent loaded ok (v5.833)
CPAN: Time::HiRes loaded ok (v1.9721)
Warning: no success downloading '/root/.cpan/sources/authors/01mailrc.txt.gz.tmp10347'. Giving up on it. at /usr/share/perl5/CPAN/Index.pm line 225
Fetching with LWP:
http://www.perl.org/CPAN/authors/01mailrc.txt.gz
CPAN: YAML loaded ok (v0.70)
Going to read '/root/.cpan/sources/authors/01mailrc.txt.gz'
............................................................................DONE
Fetching with LWP:
http://www.perl.org/CPAN/modules/02packages.details.txt.gz
................
................
.................
---30分钟 （yes）
install lib package
yum install -y perl-*
yum install -y libart_lgpl.x86_64
yum install -y mysql-mmm.noarch fail
yum install -y rrdtool.x86_64
yum install -y rrdtool-perl.x86_64
7.1 []another way to install lib package in network
cpan -i Algorithm::Diff Class::Singleton DBI DBD::mysql Log::Dispatch Log::Log4perl Mail::Send Net::Ping Proc::Daemon Time::HiRes Params::Validate Net::ARP
----------------------
2，[root@martin02 ~]# /etc/init.d/mysql-mmm-agent start
Daemon bin: '/usr/sbin/mmm_agentd'
Daemon pid: '/var/run/mmm_agentd.pid'
Starting MMM Agent daemon... Unknown variable <host in '/etc/mysql-mmm/mmm_common.conf' on line 16! at /usr/share/perl5/vendor_perl/MMM/Common/Config.pm line 224
failed
--- 出现这样的原因 是因为： hosts 和 mmm_common 中设置不一样：
3， [root@martin03 ~]# /etc/init.d/mysql-mmm-monitor restart
Daemon bin: '/usr/sbin/mmm_mond'
Daemon pid: '/var/run/mmm_mond.pid'
Daemon bin: '/usr/sbin/mmm_mond'
Daemon pid: '/var/run/mmm_mond.pid'
Shutting down MMM Monitor daemon: not running.
Daemon bin: '/usr/sbin/mmm_mond'
Daemon pid: '/var/run/mmm_mond.pid'
Starting MMM Monitor daemon: Ok
[root@martin03 ~]# mmm_control show
ERROR: Can't connect to monitor daemon!
[root@martin03 ~]# mmm_control checks all
ERROR: Can't connect to monitor daemon!
错误描述：
在monitor启动后执行mmm_contorl show时显示下列信息
ERROR: Can't connect to monitor daemon!
解决方法：
修改配置文件
将debug=0
改为
debug=1
然后重新启动mysql-mmm-monitor
4， 错误描述：
2017/03/09 04:54:48 DEBUG rep_threads(db2) = 'UNKNOWN: Connect error (host = 10.20.30.43:3306, user = mmm_monitor)! Lost connection to MySQL server at 'reading initial communication packet', system error: 111'
2017/03/09 04:54:48 DEBUG Trying initial check 'rep_threads' on host 'db3'
2017/03/09 04:54:48 DEBUG rep_threads(db3) = 'UNKNOWN: Connect error (host = 10.20.30.41:3306, user = mmm_monitor)! Lost connection to MySQL server at 'reading initial communication packet', system error: 111'
2017/03/09 04:54:48 DEBUG Trying initial check 'rep_threads' on host 'db1'
2017/03/09 04:54:48 DEBUG rep_threads(db1) = 'UNKNOWN: Connect error (host = 10.20.30.42:3306, user = mmm_monitor)! Lost connection to MySQL server at 'reading initial communication packet', system error: 111'
2017/03/09 04:54:48 INFO Shutting down checker 'rep_threads'...
2017/03/09 04:54:48 WARN No binary found for killing hosts (/usr/lib/mysql-mmm//monitor/kill_host).
2017/03/09 04:54:48 FATAL There are more than two hosts configured which can handle the active master role.
There are more than two hosts configured which can handle the active master role. at /usr/share/perl5/vendor_perl/MMM/Monitor/Monitor.pm line 262
2017/03/09 04:54:49 FATAL Child exited with exitcode 2 and has failed more than 10 times consecutively in the last 5 minutes, not restarting
错误原因：
因为你的agent配置文件里写的是this
master2 .this
master1.在host里没有对应的解析.所以无法连接。
解决方法：
1.可以在hosts.conf中写入每台mysql的主机名和IP的对应关系
2.可以使用DNS服务
3.可以在my.cnf中加入skip-name-resolve
然后重新启动mysql-mmm-monitor
4，mmm_common 中设置
mysql_port 参数：
----参考：
http://mysql-mmm.org/mysql-mmm.html
http://blog.csdn.net/mchdba/article/details/8633840
http://www.jb51.net/article/47095.htm
http://blog.csdn.net/blog_liuliang/article/details/52850320
http://blog.chinaunix.net/uid-16844903-id-3152138.html
