实验：Xenon on 5.7.30
Xenon (MySQL Plus) 是青云Qingcloud的一个开源项目，号称金融级别强一致性的高可用解决方案，项目地址为 https://github.com/radondb/xenon
本实验笔记创建与Microsoft onenote , 转换到web有格式损失。
环境信息
|
IP |
port |
role |
hostname |
|
192.168.188.51 |
3306 |
node1 |
ms51 |
|
192.168.188.52 |
3306 |
node2 |
ms52 |
|
192.168.188.53 |
3306 |
node3 |
ms53 |
|
192.168.188.54 |
3306 |
node4 |
ms54 |
|
192.168.188.50 |
3306 |
s-ip |
-- |
CentOS Linux release 7.6.1810
mysql-5.7.30-linux-glibc2.12-x86_64
xtrabackup version 2.4.20
由于Xenon本身架构的限制，暂不支持单节点多实例的方式建立高可用。可以使用docker，本来Xenon就是基于docker架构设计的。
操作系统配置
创建mysql用户，如果之前已经配置，可能需要调整mysql账号
使mysql用户可以login
[root@ms51 data]# sed -i 's#/sbin/nologin#/bin/bash#' /etc/passwd && grep mysql /etc/passwd mysql:x:2000:2000::/usr/local/mysql:/bin/bash [root@ms51 data]# echo mysql | passwd --stdin mysql
补充建立一下home目录
[root@ms51 data]# usermod -d /home/mysql mysql && mkdir /home/mysql && cp -f /root/.bash* /home/mysql/ && chown -R mysql:mysql /home/mysql && chmod -R 700 /home/mysql
配置并验证mysql的ssh互信
[mysql@ms51 ~]$ ssh-keygen [mysql@ms51 ~]$ cat .ssh/id_rsa.pub >> .ssh/authorized_keys [mysql@ms52 ~]$ scp .ssh/id_rsa.pub 192.168.188.201:/tmp/2 [mysql@ms53 ~]$ scp .ssh/id_rsa.pub 192.168.188.201:/tmp/3 [mysql@ms51 ~]$ cat /tmp/2 >> .ssh/authorized_keys [mysql@ms51 ~]$ cat /tmp/3 >> .ssh/authorized_keys [mysql@ms51 ~]$ chmod 600 .ssh/authorized_keys [mysql@ms51 ~]$ scp .ssh/authorized_keys 192.168.188.202:~/.ssh/ [mysql@ms51 ~]$ scp .ssh/authorized_keys 192.168.188.203:~/.ssh/
注意selinux， 如果开启的话，ssh互信是不生效的。
配置sudoers
将mysql加入sudoer中
[root@ms51 ~]# visudo # 或者直接vi /etc/sudoers mysql ALL=(ALL) NOPASSWD:/usr/sbin/ip
验证一下
[root@ms51 data]# su - mysql -c "sudo ip a"
有结果就ok。
软件安装
xtrabackup
略
mysql安装
略
MySQL层面的配置
这一环节主要是确认复制、半同步复制可用，配置结束后可以关闭实例。实际启用Xenon后，主从关系由Xenon选举得出，与这里的角色配置关系不大。
记得修改server-id。
配置3个实例。
启动三个数据库实例并完成基础配置
shell# mysqld --defaults-file=/data/mysql/mysql3306/my3306.cnf & mysql> set global super_read_only=0; mysql> alter user user() identified by 'mysql';
配置GTID+半同步、创建复制架构
node1、node2、node3 检查下列参数，以支持半同步开启
- gtid_mode
- enforce_gtid_consistency
- binlog_format=row
mysql> show global variables like '%GTID%'; +----------------------------------+----------------------------------------+ | Variable_name | Value | +----------------------------------+----------------------------------------+ | binlog_gtid_simple_recovery | ON | | enforce_gtid_consistency | ON | | gtid_executed | 5ea86dca-8b58-11ea-86d8-0242c0a8bc33:1 | | gtid_executed_compression_period | 1000 | | gtid_mode | ON | | gtid_owned | | | gtid_purged | | | session_track_gtids | OFF | +----------------------------------+----------------------------------------+ 8 rows in set (0.00 sec) mysql> show global variables like '%binlog_format%'; +---------------+-------+ | Variable_name | Value | +---------------+-------+ | binlog_format | ROW | +---------------+-------+ 1 row in set (0.01 sec)
创建复制用户
node1、node2、node3上都进行创建
mysql> create user 'rep'@'192.168.188.%' identified by 'rep'; Query OK, 0 rows affected (0.17 sec) mysql> grant replication slave on *.* to 'rep'@'192.168.188.%'; Query OK, 0 rows affected (0.14 sec)
配置复制架构
node1、node2、node3重置一下master status：
mysql> reset master;
node2、node3配置复制：
mysql> change master to master_host='192.168.188.51',master_port=3306,master_user='rep',master_password='rep',master_auto_position=1;
配置半同步
node1、node2、node3所有节点加载半同步库
mysql> install plugin rpl_semi_sync_slave soname 'semisync_slave.so'; Query OK, 0 rows affected (0.01 sec) mysql> install plugin rpl_semi_sync_master soname 'semisync_master.so'; Query OK, 0 rows affected (0.00 sec) mysql> show plugins; +----------------------------+----------+--------------------+--------------------+---------+ | Name | Status | Type | Library | License | +----------------------------+----------+--------------------+--------------------+---------+ | rpl_semi_sync_slave | ACTIVE | REPLICATION | semisync_slave.so | GPL | | rpl_semi_sync_master | ACTIVE | REPLICATION | semisync_master.so | GPL | +----------------------------+----------+--------------------+--------------------+---------+
node1（临时master）启用半同步
mysql> set global rpl_semi_sync_master_enabled=1; Query OK, 0 rows affected (0.00 sec) mysql> set global rpl_semi_sync_master_timeout=10000000; Query OK, 0 rows affected (0.00 sec) mysql> show global status like '%semi%'; +--------------------------------------------+-------+ | Variable_name | Value | +--------------------------------------------+-------+ | Rpl_semi_sync_master_status | ON | +--------------------------------------------+-------+ 15 rows in set (0.00 sec)
node2、node3（临时从库）启用半同步
mysql> set global rpl_semi_sync_slave_enabled=1; Query OK, 0 rows affected (0.00 sec) mysql> start slave; Query OK, 0 rows affected (0.01 sec) mysql> show global status like '%SEMI%'; +--------------------------------------------+-------+ | Variable_name | Value | +--------------------------------------------+-------+ | Rpl_semi_sync_slave_status | ON | +--------------------------------------------+-------+ 15 rows in set (0.00 sec)
看下node1，已经注册了2个半同步slave
mysql> show global status like '%semi%'; +--------------------------------------------+-------+ | Variable_name | Value | +--------------------------------------------+-------+ | Rpl_semi_sync_master_clients | 2 | | Rpl_semi_sync_master_status | ON | +--------------------------------------------+-------+ 15 rows in set (0.00 sec)
半同步复制架构配置完成。
创建数据库用户root@127.0.0.1
Xenon会用到这个用户，与后面配置文件的设定有关。
由于已经配置主从复制，直接在master上执行就可以了，让它自己复制到所有节点。
root@localhost [(none)]>create user root@127.0.0.1 identified by 'mysql'; Query OK, 0 rows affected (0.04 sec) root@localhost [(none)]>GRANT ALL PRIVILEGES ON *.* TO 'root'@'127.0.0.1' WITH GRANT OPTION; Query OK, 0 rows affected (0.04 sec) root@localhost [(none)]>grant super on *.* TO 'root'@'127.0.0.1'; Query OK, 0 rows affected (0.04 sec)
MySQL层面配置完成，接下来可以关闭全部mysql，去搞Xenon了
mysql> shutdown;
配置xenon
安装依赖
Xenon需要安装sshpass、golang。
需要在全部节点上安装依赖。
[root@ms51 data]# curl -s https://mirror.go-repo.io/centos/go-repo.repo | tee /etc/yum.repos.d/go-repo.repo [root@ms51 data]# yum install go sshpass -y
确保go在PATH中
[root@ms51 data]# go version go version go1.14.2 linux/amd64
获取、部署Xenon
可以直接通过git拉取项目，也可以通过其它途径（直接去github上下载zip）获取到项目后直接上传到每一个服务器。
通过git方式，需安装git
[root@ms51 data]# yum install git -y
git clone
[root@ms51 data]# pwd /data/ [root@ms51 data]# git clone https://github.com/radondb/xenon
clone后可以直接scp给其它节点。
通过zip方式：
从github下载zip后，依次部署到所有节点上
[root@ms51 data]# unzip /ofiles/xenon-master.zip -d /data/
编译（所有节点）
[root@ms51 data]# pwd /data [root@ms51 data]# ls mysql xenon-master [root@ms51 data]# cd xenon-master/ [root@ms51 xenon-master]# ls conf docs LICENSE makefile README.md src [root@ms51 xenon-master]# make .. [root@ms51 xenon-master]# ls bin conf docs LICENSE makefile README.md src [root@ms51 xenon-master]# ls bin/ xenon xenoncli
完成编译后， 规划文件目录结构（也可以不做）
可以复制或移动bin/ conf/ 目录， 但是不要删除或改变git项目目录及src/目录
建立config.path文件，以指定默认配置文件位置（所有节点）
后续xenoncli 命令依赖config.path文件，该文件里指定了配置文件的路径
[root@ms51 xenon-master]# cp conf/xenon-sample.conf.json xenon.json [root@ms52 xenon-master]# cp conf/xenon-sample.conf.json xenon.json [root@ms53 xenon-master]# cp conf/xenon-sample.conf.json xenon.json [root@ms53 xenon-master]# echo "/etc/xenon/xenon.json" > /data/xenon-master/bin/config.path && mkdir /etc/xenon && ln -sf /data/xenon-master/xenon.json /etc/xenon/xenon.json [root@ms52 xenon-master]# echo "/etc/xenon/xenon.json" > /data/xenon-master/bin/config.path && mkdir /etc/xenon && ln -sf /data/xenon-master/xenon.json /etc/xenon/xenon.json [root@ms53 xenon-master]# echo "/etc/xenon/xenon.json" > /data/xenon-master/bin/config.path && mkdir /etc/xenon && ln -sf /data/xenon-master/xenon.json /etc/xenon/xenon.json
将整个xenon目录所有者给mysql（所有节点）
[root@ms51 xenon-master]# chown -R mysql:mysql /data/xenon-master/ [root@ms52 xenon-master]# chown -R mysql:mysql /data/xenon-master/ [root@ms53 xenon-master]# chown -R mysql:mysql /data/xenon-master/
配置xenon.json（所有节点）
说明： server段：本机IP raft段：s-ip，要绑定s-ip的网卡名称 mysql段：指定本机mysql相关配置，host段和admin拼合起来就是前面创建root@127.0.0.1的用途。两个sysvars可以根据实际需求配置角色所需的配置动作。考虑到半同步enabled放在my.cnf文件中没有在动作中灵活，便将半同步设定也放在动作里了。 replication段： backup段：本机IP，backupdir需要注意，这个指定为mysql实例的datadir，以供xtrabackup使用。另外在执行rebuildme的时候，xenon会清空该目录以重建实例。
[root@ms51 xenon]# cat xenon.json
{
"server":
{
"endpoint":"192.168.188.51:8801"
},
"raft":
{
"meta-datadir":"raft.meta",
"heartbeat-timeout":1000,
"election-timeout":3000,
"leader-start-command":"sudo /sbin/ip a a 192.168.188.50/16 dev eth0 && arping -c 3 -A 192.168.188.50 -I eth0",
"leader-stop-command":"sudo /sbin/ip a d 192.168.188.50/16 dev eth0 "
},
"mysql":
{
"admin":"root",
"passwd":"mysql",
"host":"127.0.0.1",
"port":3306,
"basedir":"/usr/local/mysql",
"defaults-file":"/data/mysql/mysql3306/my3306.cnf",
"ping-timeout":1000,
"master-sysvars":"super_read_only=0;read_only=0;sync_binlog=default;innodb_flush_log_at_trx_commit=defaulti;rpl_semi_sync_slave_enabled=0;rpl_semi_sync_master_enabled=1",
"slave-sysvars": "super_read_only=1;read_only=1;sync_binlog=1000;innodb_flush_log_at_trx_commit=2;rpl_semi_sync_slave_enabled=1;rpl_semi_sync_master_enabled=0"
},
"replication":
{
"user":"rep",
"passwd":"rep"
},
"backup":
{
"ssh-host":"192.168.188.51",
"ssh-user":"mysql",
"ssh-passwd":"mysql",
"basedir":"/usr/local/mysql",
"backupdir":"/data/mysql/mysql3306/data",
"xtrabackup-bindir":"/usr/bin"
},
"rpc":
{
"request-timeout":500
},
"log":
{
"level":"INFO"
}
}
slave替换hostIP即可。
启动集群
mysqld可以关掉。
稳妥起见，在全部节点测试一下——切换到mysql用户，测试一下json文件的可读性及动作是否能够执行
[mysql@ms51 ~]$ cat /etc/xenon/xenon.json .. .. [mysql@ms51 ~]$ sudo /sbin/ip a a 192.168.188.50/16 dev eth0 && arping -c 3 -A 192.168.188.50 -I eth0 ARPING 192.168.188.50 from 192.168.188.50 eth0 Sent 3 probes (3 broadcast(s)) Received 0 response(s) [mysql@ms51 ~]$ ip a .. 36: eth0@if37: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default link/ether 02:42:c0:a8:bc:33 brd ff:ff:ff:ff:ff:ff link-netnsid 0 inet 192.168.188.51/24 brd 192.168.188.255 scope global eth0 valid_lft forever preferred_lft forever inet 192.168.188.50/16 scope global eth0 valid_lft forever preferred_lft forever [mysql@ms51 ~]$ sudo /sbin/ip a d 192.168.188.50/16 dev eth0 [mysql@ms51 ~]$ ip a .. 2: sit0@NONE: <NOARP> mtu 1480 qdisc noop state DOWN group default qlen 1000 link/sit 0.0.0.0 brd 0.0.0.0 36: eth0@if37: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default link/ether 02:42:c0:a8:bc:33 brd ff:ff:ff:ff:ff:ff link-netnsid 0 inet 192.168.188.51/24 brd 192.168.188.255 scope global eth0 valid_lft forever preferred_lft forever
测试通过。
启动集群吧。
启动Xenon
目前mysql没运行
【node1】启动Xenon
[mysql@ms51 ~]$ cd /data/xenon-master/ [mysql@ms51 xenon-master]$ ls bin conf docs LICENSE makefile README.md src xenon.json [mysql@ms51 xenon-master]$ bin/xenon -c /etc/xenon/xenon.json > ./xenon.log 2>&1 & [mysql@ms51 xenon-master]$ less xenon.log
检查xenon日志，可以看到xenon自己去通过mysqld_safe去启动mysql实例了，并设置为只读模式，检测了一下slave配置。
通过ps命令可以看到本机mysqld和mysqld_safe 进程，可以通过PID看出，mysqld进程是被mysqld_safe进程拉起的。
[mysql@ms51 xenon-master]$ ps -ef|grep mysql root 607 594 0 11:48 pts/0 00:00:00 su - mysql mysql 608 607 0 11:48 pts/0 00:00:00 -bash mysql 637 608 0 11:51 pts/0 00:00:01 bin/xenon -c /etc/xenon/xenon.json mysql 648 1 0 11:51 pts/0 00:00:00 /bin/sh /usr/local/mysql/bin/mysqld_safe --defaults-file=/data/mysql/mysql3306/my3306.cnf mysql 1766 648 0 11:51 pts/0 00:00:00 /usr/local/mysql/bin/mysqld --defaults-file=/data/mysql/mysql3306/my3306.cnf --basedir=/usr/local/mysql/ --datadir=/data/mysql/mysql3306/data --plugin-dir=/usr/local/mysql//lib/plugin --log-error=/data/mysql/mysql3306/logs/error.log --open-files-limit=65536 --pid-file=ms51.pid --socket=/data/mysql/mysql3306/tmp/mysql.sock --port=3306
Xenon进程
[mysql@ms51 xenon-master]$ ps -ef|grep xenon mysql 637 608 0 11:51 pts/0 00:00:01 bin/xenon -c /etc/xenon/xenon.json
在node1本地可以登录MySQL实例了
[mysql@ms51 xenon-master]$ mysql -S /data/mysql/mysql3306/tmp/mysql.sock -pmysql
启动集群后， 可以发现Xenon目录结构有新对象
[mysql@ms51 xenon-master]$ ls bin conf docs LICENSE makefile raft.meta README.md src xenon.json xenon.log [mysql@ms51 xenon-master]$ ls raft.meta/ [mysql@ms51 xenon-master]$
这个目录在xenon添加成员后会保存一个json文件peers.json，里面记录成员信息。
node1查看Xenon集群状态
[mysql@ms51 xenon-master]$ bin/xenoncli cluster status +---------------------+-------------------------------+---------+---------+--------------------------+--------------------+----------------+----------+ | ID | Raft | Mysqld | Monitor | Backup | Mysql | IO/SQL_RUNNING | MyLeader | +---------------------+-------------------------------+---------+---------+--------------------------+--------------------+----------------+----------+ | 192.168.188.51:8801 | [ViewID:0 EpochID:0]@FOLLOWER | RUNNING | ON | state:[NONE] | [ALIVE] [READONLY] | [true/true] | | | | | | | LastError: | | | | +---------------------+-------------------------------+---------+---------+--------------------------+--------------------+----------------+----------+ (1 rows)
#如果mysql列为空， 检查Xenon日志。应该是连接用户有问题，没连接上——这就是前面创建root@127.0.0.1的原因。
在node1中添加其它节点
就是xenon.json中的host段的内容，先添加node2
[mysql@ms51 xenon-master]$ bin/xenoncli cluster add 192.168.188.51:8801,192.168.188.52:8801 2020/05/01 12:03:23.654459 [WARNING] cluster.prepare.to.add.nodes[192.168.188.51:8801,192.168.188.52:8801].to.leader[] 2020/05/01 12:03:23.654522 [WARNING] cluster.canot.found.leader.forward.to[192.168.188.51:8801] 2020/05/01 12:03:23.655442 [WARNING] cluster.add.nodes.to.leader[].done
再检查集群状态
[mysql@ms51 xenon-master]$ bin/xenoncli cluster status +---------------------+-------------------------------+---------+---------+--------------------------+--------------------+----------------+----------+ | ID | Raft | Mysqld | Monitor | Backup | Mysql | IO/SQL_RUNNING | MyLeader | +---------------------+-------------------------------+---------+---------+--------------------------+--------------------+----------------+----------+ | 192.168.188.51:8801 | [ViewID:0 EpochID:1]@FOLLOWER | RUNNING | ON | state:[NONE] | [ALIVE] [READONLY] | [true/true] | | | | | | | LastError: | | | | +---------------------+-------------------------------+---------+---------+--------------------------+--------------------+----------------+----------+ | 192.168.188.52:8801 | UNKNOW | UNKNOW | UNKNOW | UNKNOW | UNKNOW | UNKNOW | UNKNOW | +---------------------+-------------------------------+---------+---------+--------------------------+--------------------+----------------+----------+ (2 rows)
启动node2的xenon节点
[mysql@ms52 ~]$ ps -ef|grep mysql root 576 24 0 12:07 pts/0 00:00:00 su - mysql mysql 577 576 0 12:07 pts/0 00:00:00 -bash mysql 594 577 0 12:07 pts/0 00:00:00 ps -ef mysql 595 577 0 12:07 pts/0 00:00:00 grep --color=auto mysql [mysql@ms52 ~]$ cd /data/xenon-master/ [mysql@ms52 xenon-master]$ bin/xenon -c /etc/xenon/xenon.json > ./xenon.log 2>&1 & [mysql@ms52 xenon-master]$ ps -ef|grep mysql root 576 24 0 12:07 pts/0 00:00:00 su - mysql mysql 577 576 0 12:07 pts/0 00:00:00 -bash mysql 596 577 0 12:07 pts/0 00:00:00 bin/xenon -c /etc/xenon/xenon.json mysql 608 1 0 12:07 pts/0 00:00:00 /bin/sh /usr/local/mysql/bin/mysqld_safe --defaults-file=/data/mysql/mysql3306/my3306.cnf mysql 1726 608 0 12:07 pts/0 00:00:00 /usr/local/mysql/bin/mysqld --defaults-file=/data/mysql/mysql3306/my3306.cnf --basedir=/usr/local/mysql/ --datadir=/data/mysql/mysql3306/data --plugin-dir=/usr/local/mysql//lib/plugin --log-error=/data/mysql/mysql3306/logs/error.log --open-files-limit=65536 --pid-file=ms52.pid --socket=/data/mysql/mysql3306/tmp/mysql.sock --port=3306
回到node1上查看集群状态，能看到node2状态了
但是此时node2并未添加成员，所以集群并未真正建立。此时不会开启选举，因此二者都是readonly状态，myleader列也都是空值。
[mysql@ms51 xenon-master]$ bin/xenoncli cluster status +---------------------+---------------------------------+---------+---------+--------------------------+--------------------+----------------+----------+ | ID | Raft | Mysqld | Monitor | Backup | Mysql | IO/SQL_RUNNING | MyLeader | +---------------------+---------------------------------+---------+---------+--------------------------+--------------------+----------------+----------+ | 192.168.188.51:8801 | [ViewID:34 EpochID:2]@CANDIDATE | RUNNING | ON | state:[NONE] | [ALIVE] [READONLY] | [true/true] | | | | | | | LastError: | | | | +---------------------+---------------------------------+---------+---------+--------------------------+--------------------+----------------+----------+ | 192.168.188.52:8801 | [ViewID:0 EpochID:0]@FOLLOWER | RUNNING | ON | state:[NONE] | [ALIVE] [READONLY] | [true/true] | | | | | | | LastError: | | | | +---------------------+---------------------------------+---------+---------+--------------------------+--------------------+----------------+----------+ (2 rows)
node2上查看集群状态，只能看到自己
[mysql@ms52 xenon-master]$ bin/xenoncli cluster status +---------------------+-------------------------------+---------+---------+--------------------------+--------------------+----------------+----------+ | ID | Raft | Mysqld | Monitor | Backup | Mysql | IO/SQL_RUNNING | MyLeader | +---------------------+-------------------------------+---------+---------+--------------------------+--------------------+----------------+----------+ | 192.168.188.52:8801 | [ViewID:0 EpochID:0]@FOLLOWER | RUNNING | ON | state:[NONE] | [ALIVE] [READONLY] | [true/true] | | | | | | | LastError: | | | | +---------------------+-------------------------------+---------+---------+--------------------------+--------------------+----------------+----------+ (1 rows)
在node2上添加集群成员node1
[mysql@ms52 xenon-master]$ bin/xenoncli cluster add 192.168.188.51:8801,192.168.188.52:8801 2020/05/01 14:49:28.836254 [WARNING] cluster.prepare.to.add.nodes[192.168.188.51:8801,192.168.188.52:8801].to.leader[] 2020/05/01 14:49:28.836297 [WARNING] cluster.canot.found.leader.forward.to[192.168.188.52:8801] 2020/05/01 14:49:28.837039 [WARNING] cluster.add.nodes.to.leader[].done [mysql@ms52 xenon-master]$ bin/xenoncli cluster status +---------------------+-------------------------------+---------+---------+--------------------------+---------------------+----------------+---------------------+ | ID | Raft | Mysqld | Monitor | Backup | Mysql | IO/SQL_RUNNING | MyLeader | +---------------------+-------------------------------+---------+---------+--------------------------+---------------------+----------------+---------------------+ | 192.168.188.52:8801 | [ViewID:4 EpochID:1]@FOLLOWER | RUNNING | ON | state:[NONE] | [ALIVE] [READONLY] | [true/true] | 192.168.188.51:8801 | | | | | | LastError: | | | | +---------------------+-------------------------------+---------+---------+--------------------------+---------------------+----------------+---------------------+ | 192.168.188.51:8801 | [ViewID:4 EpochID:1]@LEADER | RUNNING | ON | state:[NONE] | [ALIVE] [READWRITE] | [true/true] | 192.168.188.51:8801 | | | | | | LastError: | | | | +---------------------+-------------------------------+---------+---------+--------------------------+---------------------+----------------+---------------------+ (2 rows)
这个过程中node1上查看集群状态，可以发现随着选举的进行，两节点状态角色的转变
[mysql@ms51 xenon-master]$ bin/xenoncli cluster status +---------------------+--------------------------------+---------+---------+--------------------------+--------------------+----------------+----------+ | ID | Raft | Mysqld | Monitor | Backup | Mysql | IO/SQL_RUNNING | MyLeader | +---------------------+--------------------------------+---------+---------+--------------------------+--------------------+----------------+----------+ | 192.168.188.51:8801 | [ViewID:1 EpochID:1]@CANDIDATE | RUNNING | ON | state:[NONE] | [ALIVE] [READONLY] | [true/true] | | | | | | | LastError: | | | | +---------------------+--------------------------------+---------+---------+--------------------------+--------------------+----------------+----------+ | 192.168.188.52:8801 | [ViewID:0 EpochID:0]@FOLLOWER | RUNNING | ON | state:[NONE] | [ALIVE] [READONLY] | [true/true] | | | | | | | LastError: | | | | +---------------------+--------------------------------+---------+---------+--------------------------+--------------------+----------------+----------+ (2 rows) [mysql@ms51 xenon-master]$ bin/xenoncli cluster status +---------------------+-------------------------------+---------+---------+--------------------------+---------------------+----------------+---------------------+ | ID | Raft | Mysqld | Monitor | Backup | Mysql | IO/SQL_RUNNING | MyLeader | +---------------------+-------------------------------+---------+---------+--------------------------+---------------------+----------------+---------------------+ | 192.168.188.51:8801 | [ViewID:4 EpochID:1]@LEADER | RUNNING | ON | state:[NONE] | [ALIVE] [READWRITE] | [true/true] | 192.168.188.51:8801 | | | | | | LastError: | | | | +---------------------+-------------------------------+---------+---------+--------------------------+---------------------+----------------+---------------------+ | 192.168.188.52:8801 | [ViewID:4 EpochID:1]@FOLLOWER | RUNNING | ON | state:[NONE] | [ALIVE] [READONLY] | [true/true] | 192.168.188.51:8801 | | | | | | LastError: | | | | +---------------------+-------------------------------+---------+---------+--------------------------+---------------------+----------------+---------------------+ (2 rows)
这一步可以得出结论：
Xenon集群创建时，需要至少保证2个节点之间彼此添加对方为成员，才会开始选举。
否则都read only。
在node1和node2上添加成员node3，并启动node3的Xenon
[mysql@ms51 xenon-master]$ bin/xenoncli cluster add 192.168.188.51:8801,192.168.188.52:8801,192.168.188.53:8801 2020/05/01 15:00:52.517000 [WARNING] cluster.prepare.to.add.nodes[192.168.188.51:8801,192.168.188.52:8801,192.168.188.53:8801].to.leader[192.168.188.51:8801] 2020/05/01 15:00:52.518164 [WARNING] cluster.add.nodes.to.leader[192.168.188.51:8801].done [mysql@ms51 xenon-master]$ bin/xenoncli cluster status +---------------------+-------------------------------+---------+---------+--------------------------+---------------------+----------------+---------------------+ | ID | Raft | Mysqld | Monitor | Backup | Mysql | IO/SQL_RUNNING | MyLeader | +---------------------+-------------------------------+---------+---------+--------------------------+---------------------+----------------+---------------------+ | 192.168.188.51:8801 | [ViewID:6 EpochID:2]@LEADER | RUNNING | ON | state:[NONE] | [ALIVE] [READWRITE] | [true/true] | 192.168.188.51:8801 | | | | | | LastError: | | | | +---------------------+-------------------------------+---------+---------+--------------------------+---------------------+----------------+---------------------+ | 192.168.188.52:8801 | [ViewID:6 EpochID:2]@FOLLOWER | RUNNING | ON | state:[NONE] | [ALIVE] [READONLY] | [true/true] | 192.168.188.51:8801 | | | | | | LastError: | | | | +---------------------+-------------------------------+---------+---------+--------------------------+---------------------+----------------+---------------------+ | 192.168.188.53:8801 | UNKNOW | UNKNOW | UNKNOW | UNKNOW | UNKNOW | UNKNOW | UNKNOW | +---------------------+-------------------------------+---------+---------+--------------------------+---------------------+----------------+---------------------+ (3 rows) [mysql@ms53 xenon-master]$ bin/xenon -c /etc/xenon/xenon.json > xenon.log 2>&1 & [mysql@ms53 xenon-master]$ bin/xenoncli cluster status +---------------------+-------------------------------+------------+---------+--------------------------+--------------------+----------------+----------+ | ID | Raft | Mysqld | Monitor | Backup | Mysql | IO/SQL_RUNNING | MyLeader | +---------------------+-------------------------------+------------+---------+--------------------------+--------------------+----------------+----------+ | 192.168.188.53:8801 | [ViewID:0 EpochID:0]@FOLLOWER | NOTRUNNING | ON | state:[NONE] | [ALIVE] [READONLY] | [true/true] | | | | | | | LastError: | | | | +---------------------+-------------------------------+------------+---------+--------------------------+--------------------+----------------+----------+ (1 rows)
通过node1查看集群状态
[mysql@ms51 xenon-master]$ bin/xenoncli cluster status +---------------------+-------------------------------+---------+---------+--------------------------+---------------------+----------------+---------------------+ | ID | Raft | Mysqld | Monitor | Backup | Mysql | IO/SQL_RUNNING | MyLeader | +---------------------+-------------------------------+---------+---------+--------------------------+---------------------+----------------+---------------------+ | 192.168.188.51:8801 | [ViewID:6 EpochID:2]@LEADER | RUNNING | ON | state:[NONE] | [ALIVE] [READWRITE] | [true/true] | 192.168.188.51:8801 | | | | | | LastError: | | | | +---------------------+-------------------------------+---------+---------+--------------------------+---------------------+----------------+---------------------+ | 192.168.188.52:8801 | [ViewID:6 EpochID:2]@FOLLOWER | RUNNING | ON | state:[NONE] | [ALIVE] [READONLY] | [true/true] | 192.168.188.51:8801 | | | | | | LastError: | | | | +---------------------+-------------------------------+---------+---------+--------------------------+---------------------+----------------+---------------------+ | 192.168.188.53:8801 | [ViewID:0 EpochID:0]@FOLLOWER | RUNNING | ON | state:[NONE] | [ALIVE] [READONLY] | [true/true] | | | | | | | LastError: | | | | +---------------------+-------------------------------+---------+---------+--------------------------+---------------------+----------------+---------------------+ (3 rows)
node3添加集群成员，然后立即通过node1查看集群状态
[mysql@ms53 xenon-master]$ bin/xenoncli cluster add 192.168.188.51:8801,192.168.188.52:8801,192.168.188.53:8801 2020/05/01 15:04:39.640015 [WARNING] cluster.prepare.to.add.nodes[192.168.188.51:8801,192.168.188.52:8801,192.168.188.53:8801].to.leader[] 2020/05/01 15:04:39.640080 [WARNING] cluster.canot.found.leader.forward.to[192.168.188.53:8801] 2020/05/01 15:04:39.641207 [WARNING] cluster.add.nodes.to.leader[].done [mysql@ms51 xenon-master]$ bin/xenoncli cluster status +---------------------+-------------------------------+---------+---------+--------------------------+---------------------+----------------+---------------------+ | ID | Raft | Mysqld | Monitor | Backup | Mysql | IO/SQL_RUNNING | MyLeader | +---------------------+-------------------------------+---------+---------+--------------------------+---------------------+----------------+---------------------+ | 192.168.188.51:8801 | [ViewID:6 EpochID:2]@LEADER | RUNNING | ON | state:[NONE] | [ALIVE] [READWRITE] | [true/true] | 192.168.188.51:8801 | | | | | | LastError: | | | | +---------------------+-------------------------------+---------+---------+--------------------------+---------------------+----------------+---------------------+ | 192.168.188.52:8801 | [ViewID:6 EpochID:2]@FOLLOWER | RUNNING | ON | state:[NONE] | [ALIVE] [READONLY] | [true/true] | 192.168.188.51:8801 | | | | | | LastError: | | | | +---------------------+-------------------------------+---------+---------+--------------------------+---------------------+----------------+---------------------+ | 192.168.188.53:8801 | [ViewID:6 EpochID:2]@FOLLOWER | RUNNING | ON | state:[NONE] | [ALIVE] [READONLY] | [true/true] | 192.168.188.51:8801 | | | | | | LastError: | | | | +---------------------+-------------------------------+---------+---------+--------------------------+---------------------+----------------+---------------------+ (3 rows)
可以发现，在node3添加集群成员前，在集群中查看node3节点的MyLeader是空值。在node3添加集群成员后，集群状态中MyLeader列才有值。
这一步可以得出结论：MyLeader非空时才意味着节点接入了Xenon集群的业务。
启动集群后
因为踩过坑，一定要检查一下各节点半同步的状态
由于timeout设置的非常大，如果半同步未建立成功，那么数据库操作会hang，生产的话就出大事了。
node1：
mysql> show master status; +------------------+----------+--------------+------------------+------------------------------------------+ | File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set | +------------------+----------+--------------+------------------+------------------------------------------+ | mysql-bin.000005 | 194 | | | 5ea86dca-8b58-11ea-86d8-0242c0a8bc33:1-5 | +------------------+----------+--------------+------------------+------------------------------------------+ 1 row in set (0.00 sec) mysql> show slave statusG Empty set (0.00 sec) mysql> show global status like '%semi%'; +--------------------------------------------+-------+ | Variable_name | Value | +--------------------------------------------+-------+ | Rpl_semi_sync_master_clients | 2 | | Rpl_semi_sync_master_status | ON | +--------------------------------------------+-------+ 15 rows in set (0.01 sec)
node2:
mysql> show master status; +------------------+----------+--------------+------------------+------------------------------------------+ | File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set | +------------------+----------+--------------+------------------+------------------------------------------+ | mysql-bin.000006 | 194 | | | 5ea86dca-8b58-11ea-86d8-0242c0a8bc33:1-5 | +------------------+----------+--------------+------------------+------------------------------------------+ 1 row in set (0.00 sec) mysql> show slave status G .. *************************** 1. row *************************** 1 row in set (0.00 sec) mysql> mysql> show global status like '%semi%'; +--------------------------------------------+-------+ | Variable_name | Value | +--------------------------------------------+-------+ | Rpl_semi_sync_slave_status | ON | +--------------------------------------------+-------+ 15 rows in set (0.01 sec)
node3：
mysql> show master status; +------------------+----------+--------------+------------------+------------------------------------------+ | File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set | +------------------+----------+--------------+------------------+------------------------------------------+ | mysql-bin.000005 | 194 | | | 5ea86dca-8b58-11ea-86d8-0242c0a8bc33:1-5 | +------------------+----------+--------------+------------------+------------------------------------------+ 1 row in set (0.00 sec) mysql> show slave status G *************************** 1. row *************************** .. 1 row in set (0.00 sec) mysql> show global status like '%semi%'; +--------------------------------------------+-------+ | Variable_name | Value | +--------------------------------------------+-------+ | Rpl_semi_sync_slave_status | ON | +--------------------------------------------+-------+ 15 rows in set (0.00 sec)
测试一下
前面配置Xenon参数的时候已经额外增加了主从角色的sysvars，以灵活启用半同步参数。
mysql> create database kk; Query OK, 1 row affected (0.15 sec) mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | kk | | mysql | | performance_schema | | sys | +--------------------+ 5 rows in set (0.00 sec)
Xenon集群到这里就搭建完了。
通过Xenon集群进行备份、扩容节点
思路：
- 模拟业务运行：使用循环，通过sip(vip)访问数据库，并不断的插入数据。
- 建立一个新环境，配置好os、mysql和xenon，不初始化mysql实例
- 在新环境中配置xen
- 尝试通过xen的backup和rebuildme建立新节点并加入到集群
先说结论：
- 备份
- 使用Xenon备份时，备份位置必须指定绝对路径，且mysql用户对该路径具有写权限。
- 使用Xenon备份时，备份位置目录不存在时Xenon会自动通过ssh通道创建目录。
- 重建/扩容
- 为Xenon集群添加新节点时，新节点无需初始化MySQL实例，可以基于xenon backup直接rebuildme建立新节点。
- Xenon rebuildme基于xtrabackup，因此在通过rebuildme添加新节点时，需要创建好mysql datadir和my.cnf ，与xenon.json中mysql section对应参数相符合。
扩容节点的初步尝试
查看当前集群情况
[mysql@ms52 xenon-master]$ bin/xenoncli cluster status +---------------------+-------------------------------+---------+---------+--------------------------+---------------------+----------------+---------------------+ | ID | Raft | Mysqld | Monitor | Backup | Mysql | IO/SQL_RUNNING | MyLeader | +---------------------+-------------------------------+---------+---------+--------------------------+---------------------+----------------+---------------------+ | 192.168.188.51:8801 | [ViewID:3 EpochID:0]@LEADER | RUNNING | ON | state:[NONE] | [ALIVE] [READWRITE] | [true/true] | 192.168.188.51:8801 | | | | | | LastError: | | | | +---------------------+-------------------------------+---------+---------+--------------------------+---------------------+----------------+---------------------+ | 192.168.188.52:8801 | [ViewID:3 EpochID:0]@FOLLOWER | RUNNING | ON | state:[NONE] | [ALIVE] [READONLY] | [true/true] | 192.168.188.51:8801 | | | | | | LastError: | | | | +---------------------+-------------------------------+---------+---------+--------------------------+---------------------+----------------+---------------------+ | 192.168.188.53:8801 | [ViewID:3 EpochID:0]@FOLLOWER | RUNNING | ON | state:[NONE] | [ALIVE] [READONLY] | [true/true] | 192.168.188.51:8801 | | | | | | LastError: | | | | +---------------------+-------------------------------+---------+---------+--------------------------+---------------------+----------------+---------------------+ (3 rows)
集群里创建一个用户，供client角色使用
mysql> create user kk@'192.168.188.%' identified by 'kk'; Query OK, 0 rows affected (0.02 sec) mysql> grant super on *.* to kk@'192.168.188.%'; Query OK, 0 rows affected (0.02 sec) mysql> grant all privileges on *.* to kk@'192.168.188.%'; Query OK, 0 rows affected (0.01 sec)
随便找一个节点作为client角色，通过sip访问xen集群
再这里选择使用ms53节点作为client
[mysql@ms53 xenon-master]$ mysql -h 192.168.188.50 -ukk -pkk mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | kk | | mysql | | performance_schema | | sys | +--------------------+ 5 rows in set (0.00 sec) mysql> use kk Database changed mysql> show tables; Empty set (0.00 sec) mysql> create table k1(id int primary key auto_increment, numbers int); Query OK, 0 rows affected (0.04 sec) mysql> exit
模拟业务运行，不停产生事务
[mysql@ms53 xenon-master]$ while : ;do echo "insert into kk.k1(numbers) values(round(rand()*10086));" |mysql -h 192.168.188.50 -ukk -pkk ;sleep 10 ;done
另外起一个session ，查看一下表的状态
mysql> select count(*) from kk.k1; +----------+ | count(*) | +----------+ | 2779 | +----------+ 1 row in set (0.00 sec)
okay，让它先插着吧，我们去创建新环境
创建新节点
配置新节点
- 创建mysql用户
步骤略。
- 配置mysql环境
步骤略。
- 配置mysql用户ssh互信
步骤略。
- 安装xtrabackup
步骤略。
- 部署xenon
步骤略。
尝试启动xen
[mysql@ms54 xenon-master]$ bin/xenon -c /etc/xenon/xenon.json > xenon.log 2>&1 & [1] 18042 [mysql@ms54 xenon-master]$ bin/xenoncli cluster status cluster.go:227: unexpected error: get.client.error[dial tcp 192.168.188.54:8801: connect: connection refused] 2020/05/01 13:45:11.234158 [PANIC] get.client.error[dial tcp 192.168.188.54:8801: connect: connection refused] panic: [PANIC] get.client.error[dial tcp 192.168.188.54:8801: connect: connection refused] goroutine 1 [running]: xbase/xlog.(*Log).Panic(0xc000184300, 0x8d111e, 0x2, 0xc000197b28, 0x1, 0x1) /data/xenon-master/src/xbase/xlog/xlog.go:142 +0x153 cli/cmd.ErrorOK(0x9796e0, 0xc000184880) /data/xenon-master/src/cli/cmd/common.go:35 +0x245 cli/cmd.clusterStatusCommandFn(0xc0001e4fc0, 0xcac370, 0x0, 0x0) /data/xenon-master/src/cli/cmd/cluster.go:227 +0xaa vendor/github.com/spf13/cobra.(*Command).execute(0xc0001e4fc0, 0xcac370, 0x0, 0x0, 0xc0001e4fc0, 0xcac370) /data/xenon-master/src/vendor/github.com/spf13/cobra/command.go:603 +0x22e vendor/github.com/spf13/cobra.(*Command).ExecuteC(0xc78820, 0x1, 0xc000197f78, 0x40744f) /data/xenon-master/src/vendor/github.com/spf13/cobra/command.go:689 +0x2bc vendor/github.com/spf13/cobra.(*Command).Execute(...) /data/xenon-master/src/vendor/github.com/spf13/cobra/command.go:648 main.main() /data/xenon-master/src/cli/cli.go:43 +0x31
会报错，查看日志是无法访问本地mysql
无视错误，直接添加集群成员
[mysql@ms54 xenon-master]$ bin/xenoncli cluster add 192.168.188.51:8801,192.168.188.52:8801,192.168.188.53:8801,192.168.188.54:8801 2020/05/01 13:46:11.930873 [WARNING] cluster.prepare.to.add.nodes[192.168.188.51:8801,192.168.188.52:8801,192.168.188.53:8801,192.168.188.54:8801].to.leader[] 2020/05/01 13:46:11.930963 [WARNING] cluster.canot.found.leader.forward.to[192.168.188.54:8801] 2020/05/01 13:46:11.933108 [WARNING] cluster.add.nodes.to.leader[].done [mysql@ms54 xenon-master]$ bin/xenoncli cluster status +---------------------+-------------------------------+------------+---------+--------------------------+---------------------+----------------+---------------------+ | ID | Raft | Mysqld | Monitor | Backup | Mysql | IO/SQL_RUNNING | MyLeader | +---------------------+-------------------------------+------------+---------+--------------------------+---------------------+----------------+---------------------+ | 192.168.188.54:8801 | [ViewID:0 EpochID:3]@FOLLOWER | NOTRUNNING | ON | state:[NONE] | [] | [false/false] | | | | | | | LastError: | | +---------------------+-------------------------------+------------+---------+--------------------------+---------------------+----------------+---------------------+ | 192.168.188.51:8801 | [ViewID:3 EpochID:0]@LEADER | RUNNING | ON | state:[NONE] | [ALIVE] [READWRITE] | [true/true] | 192.168.188.51:8801 | | | | | | LastError: | | +---------------------+-------------------------------+------------+---------+--------------------------+---------------------+----------------+---------------------+ | 192.168.188.52:8801 | [ViewID:3 EpochID:0]@FOLLOWER | RUNNING | ON | state:[NONE] | [ALIVE] [READONLY] | [true/true] | 192.168.188.51:8801 | | | | | | LastError: | | +---------------------+-------------------------------+------------+---------+--------------------------+---------------------+----------------+---------------------+ | 192.168.188.53:8801 | [ViewID:3 EpochID:0]@FOLLOWER | RUNNING | ON | state:[NONE] | [ALIVE] [READONLY] | [true/true] | 192.168.188.51:8801 | | | | | | LastError: | | +---------------------+-------------------------------+------------+---------+--------------------------+---------------------+----------------+---------------------+ (4 rows)
竟然成功了，好像有戏！
尝试无备份情况下直接rebuild
[mysql@ms54 xenon-master]$ bin/xenoncli mysql rebuildme
2020/05/01 13:47:36.300229 [WARNING] =====prepare.to.rebuildme=====
IMPORTANT: Please check that the backup run completes successfully.
At the end of a successful backup run innobackupex
prints "completed OK!".
2020/05/01 13:47:36.300912 [WARNING] S1-->check.raft.leader
2020/05/01 13:47:36.315906 [WARNING] rebuildme.found.best.slave[192.168.188.52:8801].leader[192.168.188.51:8801]
2020/05/01 13:47:36.315973 [WARNING] S2-->prepare.rebuild.from[192.168.188.52:8801]....
2020/05/01 13:47:36.317637 [WARNING] S3-->check.bestone[192.168.188.52:8801].is.OK....
2020/05/01 13:47:36.317689 [WARNING] S4-->set.learner
2020/05/01 13:47:36.319220 [WARNING] S5-->stop.monitor
2020/05/01 13:47:36.320562 [WARNING] S6-->kill.mysql
2020/05/01 13:47:36.347934 [WARNING] S7-->check.bestone[192.168.188.52:8801].is.OK....
2020/05/01 13:47:36.351788 [WARNING] S8-->rm.datadir[/data/mysql/mysql3306/data]
2020/05/01 13:47:36.351846 [WARNING] S9-->xtrabackup.begin....
2020/05/01 13:47:36.352273 [WARNING] rebuildme.backup.req[&{From: BackupDir:/data/mysql/mysql3306/data SSHHost:192.168.188.54 SSHUser:mysql SSHPasswd:mysql SSHPort:22 IOPSLimits:100000 XtrabackupBinDir:/usr/bin}].from[192.168.188.52:8801]
2020/05/01 13:47:36.862121 [PANIC] rsp[cmd.outs.[completed OK!].found[1]!=expects[2]] != [OK]
panic: [PANIC] rsp[cmd.outs.[completed OK!].found[1]!=expects[2]] != [OK]
goroutine 1 [running]:
xbase/xlog.(*Log).Panic(0xc000094300, 0x8d8f06, 0xf, 0xc000191d88, 0x1, 0x1)
/data/xenon-master/src/xbase/xlog/xlog.go:142 +0x153
cli/cmd.RspOK(...)
/data/xenon-master/src/cli/cmd/common.go:41
cli/cmd.mysqlRebuildMeCommandFn(0xc0000e8b40, 0xcac370, 0x0, 0x0)
/data/xenon-master/src/cli/cmd/mysql.go:268 +0x847
vendor/github.com/spf13/cobra.(*Command).execute(0xc0000e8b40, 0xcac370, 0x0, 0x0, 0xc0000e8b40, 0xcac370)
/data/xenon-master/src/vendor/github.com/spf13/cobra/command.go:603 +0x22e
vendor/github.com/spf13/cobra.(*Command).ExecuteC(0xc78820, 0x1, 0xc000191f78, 0x40744f)
/data/xenon-master/src/vendor/github.com/spf13/cobra/command.go:689 +0x2bc
vendor/github.com/spf13/cobra.(*Command).Execute(...)
/data/xenon-master/src/vendor/github.com/spf13/cobra/command.go:648
main.main()
/data/xenon-master/src/cli/cli.go:43 +0x31
毫无意外的失败了
备份一下再试试
直接在新节点上执行备份
[mysql@ms54 xenon-master]$ bin/xenoncli mysql backup --to=/data/backup
2020/05/01 13:49:02.476638 [WARNING] rebuildme.found.best.slave[192.168.188.52:8801].leader[192.168.188.51:8801]
2020/05/01 13:49:02.476764 [WARNING] S1-->found.the.best.backup.host[192.168.188.52:8801]....
2020/05/01 13:49:02.483030 [WARNING] S2-->rm.and.mkdir.backupdir[/data/backup]
2020/05/01 13:49:02.483097 [WARNING] S3-->xtrabackup.begin....
2020/05/01 13:49:02.483672 [WARNING] rebuildme.backup.req[&{From: BackupDir:/data/backup SSHHost:192.168.188.54 SSHUser:mysql SSHPasswd:mysql SSHPort:22 IOPSLimits:100000 XtrabackupBinDir:/usr/bin}].from[192.168.188.52:8801]
2020/05/01 13:49:09.695471 [WARNING] S3-->xtrabackup.end....
2020/05/01 13:49:09.695495 [WARNING] S4-->apply-log.begin....
2020/05/01 13:49:15.592119 [WARNING] S4-->apply-log.end....
2020/05/01 13:49:15.592178 [WARNING] completed OK!
2020/05/01 13:49:15.592183 [WARNING] backup.all.done....
再次尝试rebuildme
依然失败。
突然想到，xtrabackup恢复的时候是需要指定my.cnf文件的， 而我当前新环境并没有！也没创建实例的数据目录！
创建目录，创建my3306.cnf
[mysql@ms54 xenon-master]$ mkdir /data/mysql/mysql3306/{data,logs,tmp} -p
[mysql@ms54 xenon-master]$ vi /data/mysql/mysql3306/my3306.cnf
终于成功了
[mysql@ms54 xenon-master]$ bin/xenoncli mysql rebuildme
2020/05/01 14:04:53.910063 [WARNING] =====prepare.to.rebuildme=====
IMPORTANT: Please check that the backup run completes successfully.
At the end of a successful backup run innobackupex
prints "completed OK!".
2020/05/01 14:04:53.910476 [WARNING] S1-->check.raft.leader
2020/05/01 14:04:53.921750 [WARNING] rebuildme.found.best.slave[192.168.188.52:8801].leader[192.168.188.51:8801]
2020/05/01 14:04:53.921809 [WARNING] S2-->prepare.rebuild.from[192.168.188.52:8801]....
2020/05/01 14:04:53.923227 [WARNING] S3-->check.bestone[192.168.188.52:8801].is.OK....
2020/05/01 14:04:53.923273 [WARNING] S4-->set.learner
2020/05/01 14:04:53.924674 [WARNING] S5-->stop.monitor
2020/05/01 14:04:53.926274 [WARNING] S6-->kill.mysql
2020/05/01 14:04:53.942920 [WARNING] S7-->check.bestone[192.168.188.52:8801].is.OK....
2020/05/01 14:04:53.945976 [WARNING] S8-->rm.datadir[/data/mysql/mysql3306/data]
2020/05/01 14:04:53.946023 [WARNING] S9-->xtrabackup.begin....
2020/05/01 14:04:53.946406 [WARNING] rebuildme.backup.req[&{From: BackupDir:/data/mysql/mysql3306/data SSHHost:192.168.188.54 SSHUser:mysql SSHPasswd:mysql SSHPort:22 IOPSLimits:100000 XtrabackupBinDir:/usr/bin}].from[192.168.188.52:8801]
2020/05/01 14:05:00.153294 [WARNING] S9-->xtrabackup.end....
2020/05/01 14:05:00.153352 [WARNING] S10-->apply-log.begin....
2020/05/01 14:05:05.228702 [WARNING] S10-->apply-log.end....
2020/05/01 14:05:05.228755 [WARNING] S11-->start.mysql.begin...
2020/05/01 14:05:05.229831 [WARNING] S11-->start.mysql.end...
2020/05/01 14:05:05.229890 [WARNING] S12-->wait.mysqld.running.begin....
2020/05/01 14:05:08.238027 [WARNING] wait.mysqld.running...
2020/05/01 14:05:08.247805 [WARNING] S12-->wait.mysqld.running.end....
2020/05/01 14:05:08.247866 [WARNING] S13-->wait.mysql.working.begin....
2020/05/01 14:05:11.250009 [WARNING] wait.mysql.working...
2020/05/01 14:05:11.250786 [WARNING] S13-->wait.mysql.working.end....
2020/05/01 14:05:11.250863 [WARNING] S14-->stop.and.reset.slave.begin....
2020/05/01 14:05:11.354249 [WARNING] S14-->stop.and.reset.slave.end....
2020/05/01 14:05:11.354321 [WARNING] S15-->reset.master.begin....
2020/05/01 14:05:11.429591 [WARNING] S15-->reset.master.end....
2020/05/01 14:05:11.430310 [WARNING] S15-->set.gtid_purged[5ea86dca-8b58-11ea-86d8-0242c0a8bc33:1-97741
].begin....
2020/05/01 14:05:11.441819 [WARNING] S15-->set.gtid_purged.end....
2020/05/01 14:05:11.441889 [WARNING] S16-->enable.raft.begin...
2020/05/01 14:05:11.443257 [WARNING] S16-->enable.raft.done...
2020/05/01 14:05:11.443320 [WARNING] S17-->wait[3000 ms].change.to.master...
2020/05/01 14:05:11.443833 [WARNING] S18-->start.slave.begin....
2020/05/01 14:05:11.494324 [WARNING] S18-->start.slave.end....
2020/05/01 14:05:11.494404 [WARNING] completed OK!
2020/05/01 14:05:11.494422 [WARNING] rebuildme.all.done....
成功了！
检查一下集群状态
[mysql@ms53 xenon-master]$ bin/xenoncli cluster status +---------------------+-------------------------------+---------+---------+--------------------------+---------------------+----------------+---------------------+ | ID | Raft | Mysqld | Monitor | Backup | Mysql | IO/SQL_RUNNING | MyLeader | +---------------------+-------------------------------+---------+---------+--------------------------+---------------------+----------------+---------------------+ | 192.168.188.51:8801 | [ViewID:5 EpochID:1]@LEADER | RUNNING | ON | state:[NONE] | [ALIVE] [READWRITE] | [true/true] | 192.168.188.51:8801 | | | | | | LastError: | | | | +---------------------+-------------------------------+---------+---------+--------------------------+---------------------+----------------+---------------------+ | 192.168.188.52:8801 | [ViewID:5 EpochID:1]@FOLLOWER | RUNNING | ON | state:[NONE] | [ALIVE] [READONLY] | [true/true] | 192.168.188.51:8801 | | | | | | LastError: | | | | +---------------------+-------------------------------+---------+---------+--------------------------+---------------------+----------------+---------------------+ | 192.168.188.53:8801 | [ViewID:5 EpochID:1]@FOLLOWER | RUNNING | ON | state:[NONE] | [ALIVE] [READONLY] | [true/true] | 192.168.188.51:8801 | | | | | | LastError: | | | | +---------------------+-------------------------------+---------+---------+--------------------------+---------------------+----------------+---------------------+ | 192.168.188.54:8801 | [ViewID:5 EpochID:1]@FOLLOWER | RUNNING | ON | state:[NONE] | [ALIVE] [READONLY] | [true/true] | 192.168.188.51:8801 | | | | | | LastError: | | | | +---------------------+-------------------------------+---------+---------+--------------------------+---------------------+----------------+---------------------+ (4 rows)
检查一下master和新节点的数据状态、同步状态
新节点：
[mysql@ms54 xenon-master]$ mysql -S /data/mysql/mysql3306/tmp/mysql.sock -pmysql mysql> select count(*) from kk.k1; +----------+ | count(*) | +----------+ | 104875 | +----------+ 1 row in set (0.01 sec)
master：
mysql> select count(*) from kk.k1; +----------+ | count(*) | +----------+ | 104875 | +----------+ 1 row in set (0.01 sec)
集群扩容成功！
Xenon集群的搭建总结：
- 集群节点数要奇数，不然影响选举。
- 半同步的status非常值得关注，由于timeout设置的非常大，如果半同步未建立成功，那么数据库操作会hang（等待ACK，但是slave永远不会发出ACK，且slave已经完成了复制过来的动作）。解决办法是手动将master复制降级为异步复制：在master上直接运行 set global rpl_semi_sync_master_enabled=0; 之后master会立即完成动作，此时再去调整各节点参数以启用半同步。
Xenon集群节点状态的探索总结：
验证过程太过冗长，直接上结论。
- 初始化集群阶段， 启动xenon@node1。此时xenon中查看集群状态，node1节点恒为read only。
- 在node1上增加成员节点node2、node3 ，启动xenon@node2。此时xenon中查看集群状态，node1节点恒为read only，node2节点恒为read only，MyLeader都为空。
- 在node2上增加成员节点node1、node3。此时通过node1查看集群状态，node1、node2节点会短时间内完成选举，胜出者成为master，节点状态变更为read/write。
- 如果3节点集群突然s2个slave都死掉， xenon在10次重试后，master会解除vip（sip），唯一存活的实例切换为read only。
- 集群内单节点存活时，单节点永远ro；大于等于2个节点时会选举master，master会rw。
- 如果所有节点上的xenon进程都被杀掉，那么sip会残留在最后绑定sip的节点上（暂称为旧master）。如果不理会旧master的xen状态，只对其它节点重启xenon后，新master会持有sip。此时两个节点查看ip的话，会发现都持有sip。但是由于arping动作，网络内其它机器都会连接到新master上。
- 接6，通过在旧master上ssh sip及mysql -h sip， 会发现旧master依然毫不知情的连接给自己， 哈哈。从这一步可以明白xenon的一个逻辑——加入xenon集群后，经过选举，落选者执行会被raft执行leader-stop-command，释放掉sip。
Xenon backup/rebuild 探索总结：
- backup 备份
- 使用Xenon备份时，备份位置必须指定绝对路径，且mysql用户对该路径具有写权限。
- 使用Xenon备份时，备份位置目录不存在时Xenon会自动通过ssh通道创建目录。
- rebuileme 重建/扩容
- 为Xenon集群添加新节点时，新节点无需初始化MySQL实例，可以基于xenon backup直接rebuildme建立新节点。
- Xenon rebuildme基于xtrabackup，因此在通过rebuildme添加新节点时，需要创建好mysql datadir和my.cnf ，与xenon.json中mysql section对应参数相符合。
https://github.com/jolleykong/gitnote_ms/blob/master/mysql/xenon_on_MySQL5.7.md