Mysql MGR + Consul + Consul-template + Haproxy 搭建mysql 高可用集群 （三）
使用consul做服务发现
Consul是一款用Go开发的分布式服务协调管理的工具，它提供了服务发现，健康检查，Key／Value存储等功能，并且支持跨数据中心的功能。
这里用consul来做mysql主从的服务发现。
Consul-template是Consul的一个扩展工具，通过监听Consul中的数据可以动态修改一些配置文件。
这里用来动态生成haproxy的配置文件。
从官网下载consul和consul-template：
wget https://releases.hashicorp.com/consul/1.4.0/consul_1.4.0_linux_amd64.zip wget https://releases.hashicorp.com/consul-template/0.19.5/consul-template_0.19.5_linux_amd64.tgz #解压后每个程序就一个单独的执行文件，将其复制到/usr/bin下： cp consul /usr/bin cp consul-template /usr/bin
配置consul集群，三个节点都服务端工作模式，同时也做客户端使用：
mkdir /root/consul cd /root/consul #swarm1： nohup consul agent -server -bootstrap-expect 2 -data-dir=./data/ -config-dir=./config/ -node=s1 \
-enable-script-checks=true -bind=172.16.0.90 -ui -client=0.0.0.0 -rejoin 2>&1 1>./consul.log & #swarm2： nohup consul agent -server -bootstrap-expect 2 -data-dir=./data/ -config-dir=./config/ -node=s2 \
-enable-script-checks=true -bind=172.16.0.76 -ui -client=0.0.0.0 -rejoin 2>&1 1>./consul.log & join 172.16.0.90 #swarm3： nohup consul agent -server -bootstrap-expect 2 -data-dir=./data/ -config-dir=./config/ -node=s3 \
-enable-script-checks=true -bind=172.16.0.175 -ui -client=0.0.0.0 -rejoin 2>&1 1>./consul.log & join 172.16.0.90 consul members Node Address Status Type Build Protocol DC Segment s1 172.16.0.90:8301 alive server 1.4.0 2 dc1 <all> s2 172.16.0.76:8301 alive server 1.4.0 2 dc1 <all> s3 172.16.0.175:8301 alive server 1.4.0 2 dc1 <all>
参数含义：
server 已服务端模式工作 bootstrap-expect N 至少N个节点集群正常工作 data-dir 数据目录 config-dir 配置目录 node=s1 节点名称 enable-script-checks 允许服务发现使用script bind 用于集群通信的绑定IP地址 ui 启动页面ui服务 client 客户端可见IP地址 rejoin 自动重新加入集群
配置mysql的服务发现，定义两个服务“mysql_rw”、“ mysql_ro”:(每台主机上分别修改address、tags)
cd /root/consul/config
vi mysql_rw.json
{
"service": {
"name": "mysql_rw",
"port": 40010,
"address": "172.16.0.90",
"tags": ["swarm1_rw"],
"checks": [
{
"interval": "10s",
"timeout": "1s",
"args": ["sh","-C","/root/consul/check_mysql_status.sh","master"]
}
]
}
}
vi mysql_ro.json
{
"service": {
"name": "mysql_ro",
"port": 40010,
"address": "172.16.0.90",
"tags": ["swarm1_ro"],
"checks": [
{
"interval": "10s",
"timeout": "1s",
"args": ["sh","-C","/root/consul/check_mysql_status.sh","slave"]
}
]
}
}
脚本内容如下，用来判断当前mysql是主节点or从节点：
[root@swarm1 config]# cat /root/consul/check_mysql_status.sh #!/bin/bash if [ ! -n "$1" ] ;then echo "you have not input a agrs! eg: sh check_mysql_status.sh [master|slave]" exit 2 fi ROLE_VALUE=$1 comm="/data/mysql_root/base_phony/40010/bin/mysql -uroot -h127.0.0.1 -P40010" value=`$comm -Nse "select 1"` server_uuid=`$comm -Nse "select VARIABLE_VALUE from performance_schema.global_variables where VARIABLE_NAME='server_uuid';"` MEMBER_ROLE=`$comm -Nse "SELECT MEMBER_ROLE from performance_schema.replication_group_members where MEMBER_ID='$server_uuid'"` MEMBER_STATE=`$comm -Nse "SELECT MEMBER_STATE from performance_schema.replication_group_members where MEMBER_ID='$server_uuid'"` echo $value echo $server_uuid echo $MEMBER_ROLE echo $MEMBER_STATE echo "check mysql" if [ $value -ne 1 ];then echo "mysql is down!!" exit 2 fi echo "check online" if [ $MEMBER_STATE != "ONLINE" ];then echo "MGR if not ONLINE!!!" exit 2 fi if [ $ROLE_VALUE == "master" ];then if [ $MEMBER_ROLE == "PRIMARY" ] ;then echo "I am master!" exit 0 else echo "I am not master!" exit 2 fi elif [ $ROLE_VALUE == "slave" ];then if [ $MEMBER_ROLE != "PRIMARY" ] ;then echo "I am slave!" exit 0 else echo "I am not slave!" exit 2 fi else echo "your arg is not master or slave!" exit 2 fi
重载consul配置，使服务发现生效：
consul reload
登录http://58.49.63.150:8500/ui ，确认rw、ro均已注册服务，一个rw，两个ro：
