mysql官方文档中有这么一句话：
MySQL Proxy is currently an Alpha release and should not be used within production environments.
So。。。
使用haproxy来做这些事，以下仅供参考：
环境配置
master 192.168.1.106 master1
slave1 192.168.1.107 master2master1(与master1主-主复制)
slave2 192.168.1.110 slave2---->master1(master1的从库)
slave3 192.168.1.111 slave3---->master1(master1的从库)
slave4 192.168.1.112 slave4----> master2(master2的从库)
monitor 192.168.1.200
192.168.1.105 eth1 写ip
192.168.1.113 eth2 读ip
说明：
当 master 停止复制， slave1 成为主库，haproxy停止发送请求到master和slave2,slave3, slave1与slave2,slave3依然可以从master接收日志。
当slave1停止复制，master成为主库，haproxy停止发送请求到slave1和slave4,master与slave4依然可以从slave1接收日志。
当 master和slave1同时停止复制，这时2台主库变成readonly模式，数据库不能写入 ,haproxy停止发送请求到slave2,slave3,slave4(脑裂)。
当slave1 offline时，master进入backup mode,haproxy停止发送请求到slave1,slave4。
当master offline时，slave1进入backup mode,haproxy停止发送请求到master,slave2,slave3。
当master和slave1同时offline,整个DB停止工作。
1、主从配置(略)
2、安装 xinetd ，配置mysqlchk服务
vi /etc/xinetd.d/mysqlchk
--两个master配置
service mysqlchk-write
{
flags = REUSE
socket_type = stream
port = 9201
wait = no
user= root
server = /opt/script/mysqlchk_status.sh
log_on_failure += USERID
disable = no
only_from = 192.168.1.0/24 #recommended toput the IPs that need
# toconnectexclusively (security purposes)
per_source = UNLIMITED
}
service mysqlchk-read
{
flags = REUSE
socket_type = stream
port = 9202
wait = no
user= root
server = /opt/script/mysqlchk_replication.sh
log_on_failure += USERID
disable = no
only_from = 192.168.1.0/24 #recommended toput the IPs that need
# toconnectexclusively (security purposes)
per_source = UNLIMITED
}
--所有slaves只需配置复制状态检查脚本
service mysqlchk-read
{
flags = REUSE
socket_type = stream
port = 9202
wait = no
user= root
server = /opt/script/mysqlchk_replication.sh
log_on_failure += USERID
disable = no
only_from = 192.168.1.0/24 #recommended toput the IPs that need
# toconnectexclusively (security purposes)
per_source = UNLIMITED
}
vi /etc/services
--两个master添加：
mysqlchk-write 9201/tcp # MySQL status check
mysqlchk-read9202/tcp # MySQL replicationcheck
--所有slaves添加：
mysqlchk-read9202/tcp # MySQL replicationcheck
重启xinetd
# /etc/init.d/xinetd stop
# /etc/init.d/xinetd start
查看端口号确认
[root@master xinetd.d]# netstat -antup|grep xinetd
tcp 0 0 0.0.0.0:9201 0.0.0.0:* LISTEN 3077/xinetd
tcp 0 0 0.0.0.0:9202 0.0.0.0:* LISTEN 3077/xinetd
3、monitor主机安装haproxy
tar zxvf haproxy-1.4.23.tar.gz
cd haproxy-1.4.23
make TARGET=linux26 ARCH=x86_64
make install
4、配置haproxy配置文件
vi /usr/local/haproxy-1.4.23/conf/haproxy-db.cfg
# HAProxy configuration - haproxy-db.cfg
global
maxconn 4096
daemon
pidfile /usr/local/haproxy-1.4.23/haproxy.pid
#debug
#quiet
#chroot /usr/share/haproxy
defaults
log global
mode http
#optionhttplog
optiondontlognull
log 127.0.0.1 local0
retries 3
optionredispatch
maxconn 4096
timeout connect1000ms
timeout client 50000ms
timeout server 50000ms
listen stats :8011
balance
mode http
stats enable
stats auth root:monitor
##
## FRONTEND ##
##
# Load-balanced IPsforDB writesandreads
#
frontend db_write
mode tcp
bind 192.168.1.105:3306
default_backend cluster_db_write
frontend db_read
mode tcp
bind 192.168.1.113:3306
default_backend cluster_db_read
# Monitor DB server availability
#
frontend monitor_master
#
# setmaster_backupto'up'or'down'
#
bind 127.0.0.1:9301
mode http
#optionnolinger
acl no_repl_master nbsrv(master_replication) eq 0
acl no_repl_slave1 nbsrv(slave1_replication) eq 0
acl no_master nbsrv(master_status) eq 0
acl no_slave1 nbsrv(slave1_status) eq 0
monitor-uri /monitor
monitor fail unless no_repl_master no_repl_slave1 no_slave1
monitor fail if no_master no_slave1
frontend monitor_slave1
#
# setslave1_backupto'up'or'down'
#
bind 127.0.0.1:9302
mode http
#optionnolinger
acl no_repl_master nbsrv(master_replication) eq 0
acl no_repl_slave1 nbsrv(slave1_replication) eq 0
acl no_master nbsrv(master_status) eq 0
acl no_slave1 nbsrv(slave1_status) eq 0
monitor-uri /monitor
monitor fail unless no_repl_master no_repl_slave1 no_master
monitor fail if no_master no_slave1
frontend monitor_slave2
#
# setslave2read-onlyslaveto'down'
#
bind 127.0.0.1:9303
mode http
#optionnolinger
acl no_repl_slave2 nbsrv(slave2_replication) eq 0
acl no_repl_master nbsrv(master_replication) eq 0
acl slave1 nbsrv(slave1_status) eq 1
monitor-uri /monitor
monitor fail if no_repl_slave2
monitor fail if no_repl_master slave1
frontend monitor_slave3
#
# setslave3read-onlyslaveto'down'
#
bind 127.0.0.1:9304
mode http
#optionnolinger
acl no_repl_slave3 nbsrv(slave3_replication) eq 0
acl no_repl_master nbsrv(master_replication) eq 0
acl slave1 nbsrv(slave1_status) eq 1
monitor-uri /monitor
monitor fail if no_repl_slave3
monitor fail if no_repl_master slave1
frontend monitor_slave4
#
# setslave4read-onlyslaveto'down'
#
bind 127.0.0.1:9305
mode http
#optionnolinger
acl no_repl_slave4 nbsrv(slave4_replication) eq 0
acl no_repl_slave1 nbsrv(slave1_replication) eq 0
acl master nbsrv(master_status) eq 1
monitor-uri /monitor
monitor fail if no_repl_slave4
monitor fail if no_repl_slave1 master
# Monitor forsplit-brain syndrome
#
frontend monitor_splitbrain
#
# setmaster_splitbrainandslave1_splitbrainto'up'
#
bind 127.0.0.1:9300
mode http
#optionnolinger
acl no_repl01 nbsrv(master_replication) eq 0
acl no_repl02 nbsrv(slave1_replication) eq 0
acl master nbsrv(master_status) eq 1
acl slave1 nbsrv(slave1_status) eq 1
monitor-uri /monitor
monitor fail unless no_repl01 no_repl02 master slave1
##
## BACKEND ##
##
# Checkevery DB server replication status
# - perform an http checkonport 9201 (replication status)
# - setto'down'if responseis'503 Service Unavailable'
# - setto'up'if responseis'200 OK'
#
backend master_replication
mode tcp
balance roundrobin
optiontcpka
optionhttpchk
server master 192.168.1.106:3306 checkport 9202 inter 5s rise 1 fall 1
backend slave1_replication
mode tcp
balance roundrobin
optiontcpka
optionhttpchk
server slave1 192.168.1.107:3306 checkport 9202 inter 5s rise 1 fall 1
backend slave2_replication
mode tcp
balance roundrobin
optiontcpka
optionhttpchk
server slave2 192.168.1.110:3306 checkport 9202 inter 5s rise 1 fall 1
backend slave3_replication
mode tcp
balance roundrobin
optiontcpka
optionhttpchk
server slave3 192.168.1.111:3306 checkport 9202 inter 5s rise 1 fall 1
backend slave4_replication
mode tcp
balance roundrobin
optiontcpka
optionhttpchk
server slave4 192.168.1.112:3306 checkport 9202 inter 5s rise 1 fall 1
# CheckMaster DB server mysql status
# - perform an http checkonport 9201 (mysql status)
# - setto'down'if responseis'503 Service Unavailable'
# - setto'up'if responseis'200 OK'
#
backend master_status
mode tcp
balance roundrobin
optiontcpka
optionhttpchk
server master 192.168.1.106:3306 checkport 9201 inter 5s rise 2 fall 2
backend slave1_status
mode tcp
balance roundrobin
optiontcpka
optionhttpchk
server slave1 192.168.1.107:3306 checkport 9201 inter 5s rise 2 fall 2
# DB write cluster
# Failure scenarios:
# - replication 'up'onmaster & slave1 = writestomaster
# - replication 'down'onslave1 = writestomaster
# - replication 'down'onmaster = writestoslave1
# - replication 'down'onmaster & slave1 = go nowhere, split-brain, cluster FAIL!
# - mysql 'down'onslave1 = writestomaster_backup
# - mysql 'down'onmaster = writestoslave1_backup
# - mysql 'down'onmaster & slave1 = go nowhere, cluster FAIL!
#
backend cluster_db_write
#
# - max1 db server availableatalltimes
# - master ispreferred (topoflist)
# - db_backups settheir'up'or'down'basedonresultsfrommonitor_monitor
#
mode tcp
optiontcpka
balance roundrobin
optionhttpchk GET /monitor
server master 192.168.1.106:3306 weight 1 checkport 9202 inter 5s rise 2 fall 1
server slave1 192.168.1.107:3306 weight 1 checkport 9202 inter 5s rise 2 fall 1 backup
server master_backup 192.168.1.106:3306 weight 1 checkport 9301 inter 5s rise 2 fall 2 addr 127.0.0.1 backup
server slave1_backup 192.168.1.107:3306 weight 1 checkport 9302 inter 5s rise 2 fall 2 addr 127.0.0.1 backup
# DB readcluster
# Failure scenarios
# - replication 'up'onmaster & slave1 = readsonmaster, slave1,alldb_slaves
# - replication 'down'onslave1 = readsonmaster, slavesofmaster
# - replication 'down'onmaster = readsonslave1, slavesofslave1
# - replication 'down'onmaster & slave1 = readsonmaster_splitbrainandmaster_splitbrainonly
# - mysql 'down'onslave1 = readsonmaster_backup, slavesofmaster
# - mysql 'down'onmaster = readsonslave1_backup, slavesofslave1
# - mysql 'down'onmaster & slave1 = go nowhere, cluster FAIL!
#
backend cluster_db_read
#
# - max2 master db servers availableatalltimes
# - maxN slave db servers availableatalltimesexceptduring split-brain
# - monitor track 'up'and'down'ofmonitorinthe cluster_db_write
# - db_backups track 'up'and'down'ofdb_backupsinthe cluster_db_write
# - db_splitbrains settheir'up'or'down'basedonresultsfrommonitor_splitbrain
#
mode tcp
optiontcpka
balance roundrobin
optionhttpchk GET /monitor
server master 192.168.1.106:3306 weight 1 track cluster_db_write/master
server slave1 192.168.1.107:3306 weight 1 track cluster_db_write/slave1
server master_backup 192.168.1.106:3306 weight 1 track cluster_db_write/master_backup
server slave1_backup 192.168.1.107:3306 weight 1 track cluster_db_write/slave1_backup
server master_splitbrain 192.168.1.106:3306 weight 1 checkport 9300 inter 5s rise 1 fall 2 addr 127.0.0.1
server slave1_splitbrain 192.168.1.107:3306 weight 1 checkport 9300 inter 5s rise 1 fall 2 addr 127.0.0.1
#
# Scaling & redundancy options
# - db_slaves settheir'up'or'down'basedonresultsfrommonitor_monitor
# - db_slaves should take longer torise
#
server slave2_slave 192.168.1.110:3306 weight 1 checkport 9303 inter 5s rise 5 fall 1 addr 127.0.0.1
server slave3_slave 192.168.1.111:3306 weight 1 checkport 9304 inter 5s rise 5 fall 1 addr 127.0.0.1
server slave4_slave 192.168.1.112:3306 weight 1 checkport 9305 inter 5s rise 5 fall 1 addr 127.0.0.1
5、启动haproxy
haproxy -f /usr/local/haproxy-1.4.23/conf/haproxy-db.cfg
监控地址：http://192.168.1.200:8011/haproxy?stats
user：root password：monitor
一些参数说明 ：
maxconn
Sets the maximum per-process number of concurrent connections to . It
is equivalent to the command-line argument "-n". Proxies will stop accepting
connections when this limit is reached.
daemon
Makes the process fork into background. This is the recommended mode of
operation. It is equivalent to the command line "-D" argument. It can be
disabled by the command line "-db" argument.
pidfile
Writes pids of all daemons into file . This option is equivalent to
the "-p" command line argument. The file must be accessible to the user
starting the process.
retries
Set the number of retries to perform on a server after a connection failure
May be used in sections: defaults | frontend | listen | backend
yes | no | yes | yes
Arguments :
is the number of times a connection attempt should be retried on
a server when a connection either is refused or times out. The
default value is 3.
It is important to understand that this value applies to the number of
connection attempts, not full requests. When a connection has effectively
been established to a server, there will be no more retry.
In order to avoid immediate reconnections to a server which is restarting,
a turn-around timer of 1 second is applied before a retry occurs.
When "option redispatch" is set, the last retry may be performed on another
server even if a cookie references a different server.
See also : "option redispatch"
option redispatch
no option redispatch
Enable or disable session redistribution in case of connection failure
May be used in sections: defaults | frontend | listen | backend
yes | no | yes | yes
Arguments : none
In HTTP mode, if a server designated by a cookie is down, clients may
definitely stick to it because they cannot flush the cookie, so they will not
be able to access the service anymore.
Specifying "option redispatch" will allow the proxy to break their
persistence and redistribute them to a working server.
It also allows to retry last connection to another server in case of multiple
connection failures. Of course, it requires having "retries" set to a nonzero
value.
This form is the preferred form, which replaces both the "redispatch" and
"redisp" keywords.
If this option has been enabled in a "defaults" section, it can be disabled
in a specific instance by prepending the "no" keyword before it.
option dontlognull
no option dontlognull
Enable or disable logging of null connections
May be used in sections : defaults | frontend | listen | backend
yes | yes | yes | no
Arguments : none
In certain environments, there are components which will regularly connect to
various systems to ensure that they are still alive. It can be the case from
another load balancer as well as from monitoring systems. By default, even a
simple port probe or scan will produce a log. If those connections pollute
the logs too much, it is possible to enable option "dontlognull" to indicate
that a connection on which no data has been transferred will not be logged,
which typically corresponds to those probes.
It is generally recommended not to use this option in uncontrolled
environments (eg: internet), otherwise scans and other malicious activities
would not be logged.
If this option has been enabled in a "defaults" section, it can be disabled
in a specific instance by prepending the "no" keyword before it.
另外，使用keepalived实现代理层的HA。
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