Mycat实现读写分离架构图：

Mycat主从自动切换架构图：

Mycat下载地址：http://dl.mycat.io/1.6.7.3/20190828135747/Mycat-server-1.6.7.3-release-20190828135747-linux.tar.gz

Percona-XtraDB-Cluster下载地址：https://www.percona.com/downloads/Percona-XtraDB-Cluster-57/LATEST/

Percona-XtraBackup下载地址：https://www.percona.com/downloads/Percona-XtraBackup-2.4/LATEST/

yum仓库地址：https://www.percona.com/downloads/percona-release/redhat/

1.下载，安装Percona-XtraDB-Cluster（三台都需要装）
[root@k8s01 ~]# rpm -ivh https://www.percona.com/redir/downloads/percona-release/redhat/1.0-13/percona-release-1.0-13.noarch.rpm

[root@k8s01 ~]# yum repolist

[root@k8s01 ~]# rpm -ivh percona-xtrabackup-24-2.4.13-1.el7.x86_64.rpm

[root@k8s01 ~]# yum install Percona-XtraDB-Cluster-57 -y

2.修改配置，启动服务（k8s01节点）

[root@k8s01 ~]# vim /etc/percona-xtradb-cluster.conf.d/mysqld.cnf

log-bin=k8s01-bin
log-bin-index=k8s01-bin-index

[root@k8s01 ~]# vim /etc/percona-xtradb-cluster.conf.d/wsrep.cnf

[mysqld]

wsrep_provider=/usr/lib64/galera3/libgalera_smm.so

wsrep_cluster_address=gcomm://192.168.54.129,192.168.54.130,192.168.54.128

binlog_format=ROW

default_storage_engine=InnoDB

wsrep_slave_threads= 8

wsrep_log_conflicts

innodb_autoinc_lock_mode=2

wsrep_node_address=192.168.54.128 --三个节点值不一样

wsrep_cluster_name=mycluster

wsrep_node_name=k8s01

pxc_strict_mode=ENFORCING

wsrep_sst_method=xtrabackup-v2

wsrep_sst_auth="sstuser:s3cretPass"

[root@k8s01 ~]# mysql_install_db --defaults-file=/etc/percona-xtradb-cluster.cnf --datadir=/var/lib/mysql--初使化数据

[root@k8s01 ~]# systemctl start mysql@bootstrap.service --第一次启动，不需要同步数据
[root@k8s01 ~]# ps -ef | grep mysql
root 60672 54285 0 14:56 pts/1 00:00:00 tailf /var/log/mysqld.log
root 66031 1 0 15:03 ? 00:00:00 /bin/sh /usr/bin/mysqld_safe --basedir=/usr --wsrep-new-cluster
mysql 66568 66031 6 15:03 ? 00:00:01 /usr/sbin/mysqld --basedir=/usr --datadir=/var/lib/mysql --plugin-dir=/usr/lib64/mysql/plugin --user=mysql --wsrep-provider=/usr/lib64/galera3/libgalera_smm.so --wsrep-new-cluster --log-error=
/var/log/mysqld.log --pid-file=/var/run/mysqld/mysqld.pid --socket=/var/lib/mysql/mysql.sock --wsrep_start_position=00000000-0000-0000-0000-000000000000:-1root 66763 33815 0 15:04 pts/0 00:00:00 grep --color=auto mysql

[root@k8s01 ~]# cat ~/.mysql_secret
# Password set for user 'root@localhost' at 2019-11-15 14:40:31
ya;-t*taM8T<--mysql登陆密码
[root@k8s01 ~]# mysql -u root -p'ya;-t*taM8T<'
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 13
Server version: 5.7.27-30-57-logCopyright (c) 2009-2019 Percona LLC and/or its affiliates
Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective owners.Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> set password=password('System135');
Query OK, 0 rows affected, 1 warning (0.02 sec)mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)mysql> exit
Bye
[root@k8s01 ~]# mysql -u root -pSystem135
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 16
Server version: 5.7.27-30-57-log Percona XtraDB Cluster (GPL), Release rel30, Revision 64987d4, WSREP version 31.39, wsrep_31.39Copyright (c) 2009-2019 Percona LLC and/or its affiliates
Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective owners.Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.mysql> grant all privileges on *.* to sstuser@'%' identified by 's3cretPass'; --创建percona xtradb cluster用户
Query OK, 0 rows affected, 1 warning (0.05 sec)mysql> flush privileges;
Query OK, 0 rows affected (0.01 sec)mysql> exit
Bye
[root@k8s01 ~]#

3.修改配置，启动服务（k8s02节点）

[root@k8s02 ~]# vim /etc/percona-xtradb-cluster.conf.d/mysqld.cnf

log-bin=k8s01-bin
log-bin-index=k8s01-bin-index

[root@k8s02 ~]# vim /etc/percona-xtradb-cluster.conf.d/wsrep.cnf

[mysqld]

wsrep_provider=/usr/lib64/galera3/libgalera_smm.so

wsrep_cluster_address=gcomm://192.168.54.128,192.168.54.129,192.168.54.130

binlog_format=ROW

default_storage_engine=InnoDB

wsrep_slave_threads= 8

wsrep_log_conflicts

innodb_autoinc_lock_mode=2

wsrep_node_address=192.168.54.129

wsrep_cluster_name=mycluster

wsrep_node_name=k8s02

pxc_strict_mode=ENFORCING

wsrep_sst_method=xtrabackup-v2

wsrep_sst_auth="sstuser:s3cretPass"

[root@k8s02 ~]# systemctl start mysql

4.修改配置，启动服务（k8s03节点）

[root@k8s03 ~]# vim /etc/percona-xtradb-cluster.conf.d/mysqld.cnf

log-bin=k8s01-bin
log-bin-index=k8s01-bin-index
[root@k8s03 ~]# vim /etc/percona-xtradb-cluster.conf.d/wsrep.cnf

[mysqld]

wsrep_provider=/usr/lib64/galera3/libgalera_smm.so

wsrep_cluster_address=gcomm://192.168.54.128,192.168.54.129,192.168.54.130
binlog_format=ROW

default_storage_engine=InnoDB

wsrep_slave_threads= 8

wsrep_log_conflicts

innodb_autoinc_lock_mode=2

wsrep_node_address=192.168.54.130

wsrep_cluster_name=mycluster

wsrep_node_name=k8s03

pxc_strict_mode=ENFORCING

wsrep_sst_method=xtrabackup-v2

wsrep_sst_auth="sstuser:s3cretPass"

[root@k8s03 ~]# systemctl start mysql

5.测试Percona-XtraDB-Cluster集群数据同步

k8s01节点：

[root@k8s01 ~]# mysql -u root -pSystem135
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 22
Server version: 5.7.27-30-57-log Percona XtraDB Cluster (GPL), Release rel30, Revision 64987d4, WSREP version 31.39, wsrep_31.39Copyright (c) 2009-2019 Percona LLC and/or its affiliates
Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective owners.Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.mysql> create database wuhan charset utf8;
Query OK, 1 row affected (0.01 sec)
mysql> use wuhan
Database changed
mysql> create table t (a int primary key,b int);
Query OK, 0 rows affected (0.02 sec)mysql> insert into t values(1,2),(2,3);
Query OK, 2 rows affected (0.02 sec)
Records: 2 Duplicates: 0 Warnings: 0mysql> select * from t;
+---+------+
| a | b |
+---+------+
| 1 | 2 |
| 2 | 3 |
+---+------+
2 rows in set (0.00 sec)mysql> exit
Bye
[root@k8s01 ~]#

k8s02节点：

[root@k8s02 ~]# mysql -u root -pSystem135
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 12
Server version: 5.7.27-30-57-log Percona XtraDB Cluster (GPL), Release rel30, Revision 64987d4, WSREP version 31.39, wsrep_31.39Copyright (c) 2009-2019 Percona LLC and/or its affiliates
Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective owners.Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.mysql> use wuhan
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -ADatabase changed
mysql> select * from t;
+---+------+
| a | b |
+---+------+
| 1 | 2 |
| 2 | 3 |
+---+------+
2 rows in set (0.01 sec)mysql> exit
Bye
[root@k8s02 ~]#

6.下载，安装Mycat中间件

[root@[root@k8s01 soft]# rpm -ivh jdk-8u221-linux-x64.rpm
warning: jdk-8u221-linux-x64.rpm: Header V3 RSA/SHA256 Signature, key ID ec551f03: NOKEY
Preparing... ################################# [100%]
Updating / installing...
1:jdk1.8-2000:1.8.0_221-fcs ################################# [100%]
Unpacking JAR files...
tools.jar...
plugin.jar...
javaws.jar...
deploy.jar...
rt.jar...
jsse.jar...
charsets.jar...
localedata.jar...
[root@k8s01 soft]# tar xvf Mycat-server-1.6.7.3-release-20190828135747-linux.tar.gz -C /usr/local/
[root@k8s01 soft]# cd /usr/local/mycat/conf/

[root@k8s01 conf]# vim schema.xml

[root@k8s01 conf]# vim server.xml

<user name="root" defaultAccount="true">
<property name="password">System135</property>
<property name="schemas">hubei</property>
</user>

[root@k8s01 conf]# ../bin/mycat restart
Stopping Mycat-server...
Mycat-server was not running.
Starting Mycat-server...
[root@k8s01 conf]# netstat -antulp | grep 9066
tcp6 0 0 :::9066 :::* LISTEN 100087/java
[root@k8s01 conf]#

7.使用Mycat验证读，写数据

(1).查看管理端口服务

(2).查看数据，如果想要看负载均衡效果，必须退出终端，再登陆。

(3).k8s01节点写入数据，k8s02和k8s03读数据

8.k8s01节点宕机后，k8s02节点负责写入数据，k8s03读数据

[root@k8s01 conf]# systemctl stop mysql@bootstrap.service

[root@k8s01 conf]# netstat -antulp | grep 3306
tcp6 0 0 10.4.132.50:60568 10.4.132.42:3306 ESTABLISHED 100087/java
tcp6 0 0 10.4.132.50:51072 10.4.132.66:3306 ESTABLISHED 100087/java
[root@k8s01 conf]# ps -ef | grep mysqld
root 115559 33815 0 16:58 pts/0 00:00:00 grep --color=auto mysqld

[root@k8s01 conf]#(1).关闭k8s01节点的mysql，写入一条数据，读取一次。

(2).写入节点是k8s02，读节点是k8s03

错误处理:

(1).Mysql没有初使化数据

2019-11-15T06:33:04.384904Z 0 [Note] Server socket created on IP: '::'.
2019-11-15T06:33:04.385584Z 0 [Warning] Failed to open optimizer cost constant tables

2019-11-15T06:33:04.385659Z 0 [ERROR] Fatal error: Can't open and lock privilege tables: Table 'mysql.user' doesn't exist
2019-11-15T06:33:04.385668Z 0 [ERROR] Fatal error: Failed to initialize ACL/grant/time zones structures or failed to remove temporary table files.
2019-11-15T06:33:04.385687Z 0 [ERROR] Aborting

解决方法：

[root@k8s01 conf]# mysql_install_db --defaults-file=/etc/percona-xtradb-cluster.cnf --datadir=/var/lib/mysql--需要初使化数据

(2).第一个节点第一次启动必须要创建新的集群

2019-11-15T06:41:35.761089Z 0 [Note] WSREP: Current view of cluster as seen by this node
view ((empty))
2019-11-15T06:41:35.761280Z 0 [ERROR] WSREP: failed to open gcomm backend connection: 110: failed to reach primary view (pc.wait_prim_timeout): 110 (Connection timed out)
at gcomm/src/pc.cpp:connect():159
2019-11-15T06:41:35.761309Z 0 [ERROR] WSREP: gcs/src/gcs_core.cpp:gcs_core_open():209: Failed to open backend connection: -110 (Connection timed out)
2019-11-15T06:41:35.761583Z 0 [ERROR] WSREP: gcs/src/gcs.cpp:gcs_open():1514: Failed to open channel 'pxc_1' at 'gcomm://192.168.54.128,192.168.54.129,192.168.54.130': -110 (Connection timed out)
2019-11-15T06:41:35.761597Z 0 [ERROR] WSREP: gcs connect failed: Connection timed out
2019-11-15T06:41:35.761600Z 0 [ERROR] WSREP: Provider/Node (gcomm://192.168.54.128,192.168.54.129,192.168.54.130) failed to establish connection with cluster (reason: 7)
2019-11-15T06:41:35.761603Z 0 [ERROR] Aborting

解决方法：

[root@k8s01 ~]# systemctl start mysql@bootstrap.service --必须添加@bootstrap.service启动服务

(3).没有创建wsrep.cnf用户名

2019-11-15T07:27:59.158666Z 0 [ERROR] WSREP: Command did not run: wsrep_sst_xtrabackup-v2 --role 'donor' --address '192.168.54.129:4444/xtrabackup_sst//1' --socket '/var/lib/mysql/mysql.sock' --datadir '/var/lib/mysql/' --defaults-file '/etc/my.cnf' --defaults-group-suf
fix '' --mysqld-version '5.7.27-30-57' '' --gtid '19a21dce-0776-11ea-8879-92a989219bb1:2'2019-11-15T07:27:59.159302Z 0 [Warning] WSREP: Protocol violation. JOIN message sender 0.0 (k8s01) is not in state transfer (SYNCED). Message ignored.
2019-11-15T07:27:59.159405Z 5 [Note] WSREP: Synchronized with group, ready for connections

解决方法：

[root@k8s01 conf]# grep sst /etc/percona-xtradb-cluster.conf.d/wsrep.cnf
wsrep_sst_method=xtrabackup-v2
wsrep_sst_auth="sstuser:s3cretPass"
[root@k8s01 conf]#

mysql> grant all privileges on *.* to sstuser@'%' identified by 's3cretPass'; --创建用户
Query OK, 0 rows affected, 1 warning (0.05 sec)mysql> flush privileges;
Query OK, 0 rows affected (0.01 sec)

mysql> exit
Bye
[root@k8s01 ~]#