利用官方yum源安装Percona-XtraDB-Cluster-57
1.当前OS环境:
[root@qht131 local]# more /etc/redhat-release
Red Hat Enterprise Linux Server release 6.3 (Santiago)
配置hosts文件
[root@qht131 local]# cat /etc/hosts
127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4
::1 localhost localhost.localdomain localhost6 localhost6.localdomain6
172.17.61.131 qht131
172.17.61.132 qht132
172.17.61.133 qht133
修改selinux配置文件
[root@qht131 local]# cat /etc/selinux/config
# This file controls the state of SELinux on the system.
# SELINUX= can take one of these three values:
# enforcing - SELinux security policy is enforced.
# permissive - SELinux prints warnings instead of enforcing.
# disabled - No SELinux policy is loaded.
SELINUX=disabled
# SELINUXTYPE= can take one of these two values:
# targeted - Targeted processes are protected,
# mls - Multi Level Security protection.
SELINUXTYPE=targeted
关闭防火墙
[root@qht131 local]# chkconfig iptables off
或者打开这几个端口也可以:
3306 数据库对外提供服务的端口
4444 镜像数据传输SST,集群数据同步端口,全量同步,新节点加入时起作用
4567 集群节点间相互通信的端口
4568 增量数据同步IST,节点下线、重启后使用该端口,增量同步数据。
2.准备安装
配置percona的yum文件
[root@qht131 ~]# cd /etc/yum.repos.d/
[root@qht131 yum.repos.d]# sudo yum install http://www.percona.com/downloads/percona-release/redhat/0.1-4/percona-release-0.1-4.noarch.rpm
Installed:
percona-release.noarch 0:0.1-4
Complete!
测试一下yum,
[root@qht131 yum.repos.d]# sudo yum list | grep percona
Unable to read consumer identity
percona-release.noarch 0.1-4 @/percona-release-0.1-4.noarch
Percona-SQL-50-debuginfo.x86_64 5.0.92-b23.89.rhel6 percona-release-x86_64
Percona-SQL-client-50.x86_64 5.0.92-b23.89.rhel6 percona-release-x86_64
Percona-SQL-devel-50.x86_64 5.0.92-b23.89.rhel6 percona-release-x86_64
Percona-SQL-server-50.x86_64 5.0.92-b23.89.rhel6 percona-release-x86_64
Percona-SQL-shared-50.x86_64 5.0.92-b23.89.rhel6 percona-release-x86_64
Percona-SQL-shared-compat.x86_64 5.0.92-b23.89.rhel6 percona-release-x86_64
Percona-SQL-test-50.x86_64 5.0.92-b23.89.rhel6 percona-release-x86_64
。。。
3.安装Percona XtraDB Cluster5.7
[root@qht131 ~]# sudo yum install Percona-XtraDB-Cluster-57
正常安装完成后应该是这样:
Installed:
Percona-XtraDB-Cluster-57.x86_64 0:5.7.21-29.26.1.el6
Dependency Installed:
Percona-XtraDB-Cluster-client-57.x86_64 0:5.7.21-29.26.1.el6 Percona-XtraDB-Cluster-server-57.x86_64 0:5.7.21-29.26.1.el6
Percona-XtraDB-Cluster-shared-57.x86_64 0:5.7.21-29.26.1.el6 percona-xtrabackup-24.x86_64 0:2.4.11-1.el6
perl-DBD-MySQL.x86_64 0:4.013-3.el6 qpress.x86_64 0:11-1.el6
Dependency Updated:
zlib.x86_64 0:1.2.3-29.el6
Complete!
更改root密码:
mysql没有启动的话需要手工启动一下,我是reboot系统后才可能正常启动的,还不知道是为什么
[root@qht131 ~]# service mysql status
MySQL (Percona XtraDB Cluster) running (1974) [ OK ]
mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY '123456';
Query OK, 0 rows affected (0.04 sec)
mysql> exit
Bye
[root@qht131 ~]# service mysql stop
Shutting down MySQL (Percona XtraDB Cluster)...............[ OK ]
由于我是虚拟机测试的,这时我把qht131复制成qht132,qht133,更改IP后启动,特别注意需要更改mysql的server-uuid.
位置在:
[root@qht131 mysql]# cat /var/lib/mysql/auto.cnf
[auto]
server-uuid=b6315eab-6f16-11e8-84e3-000c29b55066
4.修改Write-Set Replication
先要确保三台mysql是关闭的状态
[root@qht131 ~]# service mysql stop
Shutting down MySQL (Percona XtraDB Cluster)...............[ OK ]
接着修改/etc/my.cnf
[root@qht131 ~]# grep "^[^#]" /etc/my.cnf
[mysqld] --这个必须加上,默认是没有的
!includedir /etc/my.cnf.d/
!includedir /etc/percona-xtradb-cluster.conf.d/
wsrep_provider=/usr/lib64/galera3/libgalera_smm.so
wsrep_cluster_name=pxc-cluster
wsrep_cluster_address=gcomm://172.17.61.131,172.17.61.132,172.17.61.133
wsrep_node_name=pxc1
wsrep_node_address=172.17.61.131
wsrep_sst_method=xtrabackup-v2
wsrep_sst_auth=sstuser:sstuser
pxc_strict_mode=ENFORCING
binlog_format=ROW
default_storage_engine=InnoDB
innodb_autoinc_lock_mode=2
qht132和qht133只需要改动wsrep_node_address以及wsrep_node_nam,其它的参数和qht132一致。
接着开启第一个节点:(centos7的启动方法是[root@pxc1 ~]# systemctl start [email protected])
[root@qht131 ~]# /etc/init.d/mysql bootstrap-pxc
查看一下关于Write-Set Replication的参数 :
mysql> show status like 'wsrep%';
+----------------------------------+-----------------------------------------------+
| Variable_name | Value |
+----------------------------------+-----------------------------------------------+
| wsrep_local_state_uuid | a084e15e-6f18-11e8-9dc4-efc0d77a254c |
|。。。
| wsrep_local_state | 4 |
| wsrep_local_state_comment | Synced |
。。。
| wsrep_incoming_addresses | 172.17.61.131:3306 |
。。。
| wsrep_cluster_size | 1 |
| wsrep_cluster_state_uuid | a084e15e-6f18-11e8-9dc4-efc0d77a254c |
| wsrep_cluster_status | Primary |
| wsrep_connected | ON |
。。。
| wsrep_ready | ON |
+----------------------------------+-----------------------------------------------+
68 rows in set (0.00 sec)
表示当前的cluster_size为1,是Primary的组件,当前的状态是synced,wsrep_ready是开启的状态
当前的监听端口3306和4567都已打开
[root@qht131 ~]# ss -ntl
Recv-Q Send-Q Local Address:Port Peer Address:Port
0 128 :::43753 :::*
0 80 :::3306 :::*
0 128 :::111 :::*
0 128 *:111 *:*
0 64 :::9200 :::*
0 128 :::22 :::*
0 128 *:22 *:*
0 128 *:4567 *:*
0 128 127.0.0.1:631 *:*
0 128 ::1:631 :::*
0 100 ::1:25 :::*
0 100 127.0.0.1:25 *:*
0 128 *:52412 *:*
在初始化启动节点1的mysql后,需要创建用于节点直接同步数据的账户。
在新节加入到集群之前,在第一个节点需要建立sst用户,帐户名和密码是wsrep_sst_auth里面设置的一致。
默认情况下percona xtrDB Cluster是用Xtrabackup来做SST(State Snapshot Transfer ),所以需要建立一个用户并给予相应的权限。
mysql> CREATE USER 'sstuser'@'localhost' IDENTIFIED BY 'sstuser';
Query OK, 0 rows affected (0.03 sec)
mysql> GRANT RELOAD, LOCK TABLES, PROCESS, REPLICATION CLIENT ON *.* TO 'sstuser'@'localhost';
Query OK, 0 rows affected (0.00 sec)
mysql> FLUSH PRIVILEGES;
Query OK, 0 rows affected (0.00 sec)
下一步就是开始其它的2个别点,加入到cluster中。
[root@qht132 ~]# /etc/init.d/mysql start
Starting MySQL (Percona XtraDB Cluster)....State transfer in progress, setting sleep higher
. [ OK ]
[root@qht133 ~]# /etc/init.d/mysql start
Starting MySQL (Percona XtraDB Cluster)...State transfer in progress, setting sleep higher
. [ OK ]
三个节都起来后,查看一下wsrep的相关参数 :
mysql> show status like '%wsrep_cluster%';
+--------------------------+--------------------------------------+
| Variable_name | Value |
+--------------------------+--------------------------------------+
| wsrep_cluster_conf_id | 3 |
| wsrep_cluster_size | 3 |
| wsrep_cluster_state_uuid | a084e15e-6f18-11e8-9dc4-efc0d77a254c |
| wsrep_cluster_status | Primary |
+--------------------------+--------------------------------------+
4 rows in set (0.00 sec)
mysql> show status like 'wsrep_connected';
+-----------------+-------+
| Variable_name | Value |
+-----------------+-------+
| wsrep_connected | ON |
+-----------------+-------+
1 row in set (0.00 sec)
5.验证集群:
在qht132中建立些测试数据:
mysql> CREATE DATABASE percona;
Query OK, 1 row affected (0.03 sec)
mysql> USE percona;
Database changed
mysql> CREATE TABLE example (node_id INT PRIMARY KEY, node_name VARCHAR(30));
Query OK, 0 rows affected (0.04 sec)
mysql> INSERT INTO percona.example VALUES (1, 'percona1');
Query OK, 1 row affected (0.07 sec)
mysql> SELECT * FROM percona.example;
+---------+-----------+
| node_id | node_name |
+---------+-----------+
| 1 | percona1 |
+---------+-----------+
1 row in set (0.00 sec)
qht133中查看新数据:
mysql> SELECT * FROM percona.example;
+---------+-----------+
| node_id | node_name |
+---------+-----------+
| 1 | percona1 |
+---------+-----------+
1 row in set (0.00 sec)
mysql> INSERT INTO percona.example VALUES (2, 'percona1');
Query OK, 1 row affected (0.04 sec)
qht131中查看数据:
mysql> SELECT * FROM percona.example;
+---------+-----------+
| node_id | node_name |
+---------+-----------+
| 1 | percona1 |
| 2 | percona1 |
+---------+-----------+
2 rows in set (0.00 sec)
PXC集群内的所有节点均可写入并同步复制到其他节点。
接着测试如果一个节点挂掉后再重新加入到cluster会不会同步数据。
将qht132的mysql停掉
qht132:
[root@qht132 ~]# /etc/init.d/mysql stop
Shutting down MySQL (Percona XtraDB Cluster).............. [ OK ]
qht131:
mysql> show status like '%wsrep_clust%';
+--------------------------+--------------------------------------+
| Variable_name | Value |
+--------------------------+--------------------------------------+
| wsrep_cluster_conf_id | 4 |
| wsrep_cluster_size | 2 |
| wsrep_cluster_state_uuid | a084e15e-6f18-11e8-9dc4-efc0d77a254c |
| wsrep_cluster_status | Primary |
+--------------------------+--------------------------------------+
4 rows in set (0.00 sec)
当前的cluster_size为2,说明只有2个节点是存活的。
mysql> INSERT INTO percona.example VALUES (3, 'percona1');
Query OK, 1 row affected (0.00 sec)
qht132:
[root@qht132 ~]# /etc/init.d/mysql start
Starting MySQL (Percona XtraDB Cluster).... [ OK ]
mysql> SELECT * FROM percona.example;
+---------+-----------+
| node_id | node_name |
+---------+-----------+
| 1 | percona1 |
| 2 | percona1 |
| 3 | percona1 |
+---------+-----------+
3 rows in set (0.00 sec)
没有问题,qht132重新加入到cluster后,数据也同步了过来。
经过测试,3个节点中任何一个节点挂掉后重新再加入cluster都能正常的同步数据,包括qht131。
由此可见,当集群内的某个节点掉线后,其他节点仍可以正常的工作,新写入的数据会在该节点重新上线后完成同步,以实现PXC的高可用。
针对重新上线的节点,PXC有两种方式完成数据传输以保证数据同步:State Snapshot Transfer (SST)和Incremental State Transfer (IST)。
SST通常用在当有新的节点加入PXC集群同时从已存在节点复制全部数据时采用,在PXC中有三种可用的方式完成SST过程:
– mysqldump
– rsync
– xtrabackup
mysqldump和rsync的缺点是在数据传输过程中,PXC集群将会变成只读模式,SST将会对数据库施加只读锁(FLUSH TABLES WITH READ LOCK)。而使用xtrabackup则不需要再数据同步过程中施加读锁,仅仅是同步.frm文件,类似于常规的备份。
尽管,如果SST使用xtrabackup不需要施加读锁,SST仍可能扰乱了服务的正常运行。而IST则不会。如果一个节点掉线时间较短,当再次上线,它将只会从其他节点获取掉线期间的数据变化部分。IST是在节点上使用缓存机制实现的。每个节点包含一个缓存,且环形缓冲区(大小是可配置的)存储最后N个变化,并且节点能够传输该缓存的一部分。显然,只有当传输所需的更改量小于N时,才可以执行IST,如果超过N,则加入的节点必须执行SST。
参考:
https://www.percona.com/doc/percona-xtradb-cluster/5.7/install/index.html
https://blog.csdn.net/geoffreychan/article/details/80499956