MySQL PXC 高可用集群搭建

一些名词介绍：

WS：write set 写数据集
    IST: Incremental State Transfer 增量同步
    SST：State Snapshot Transfer 全量同步

pxc环境所涉及的端口：

#mysql实例端口

1. Regular MySQL port, default 3306.

#pxc cluster相互通讯的端口
   2. Port for group communication, default 4567. It can be changed by the option:  
       wsrep_provider_options ="gmcast.listen_addr=tcp://0.0.0.0:4010; "

#用于SST传送的端口
   3. Port for State Transfer, default 4444. It can be changed by the option: 
       wsrep_sst_receive_address=10.11.12.205:5555

#用于IST传送的端口
   4. Port for Incremental State Transfer, default port for group communication + 1 (4568). It can be changed by the option: 
       wsrep_provider_options = "ist.recv_addr=10.11.12.206:7777; "

搭建步骤：

一、环境情况：

node1:192.168.1.81:6000

node2:192.168.1.240:6000

     node3:192.168.1.241:6000

 

二、防火墙设置：

-A INPUT -m state --state NEW -m tcp -p tcp --dport  -j ACCEPT #本实验需要改为6000
-A INPUT -m state --state NEW -m tcp -p tcp --dport  -j ACCEPT #本实验需要改为6020
-A INPUT -m state --state NEW -m tcp -p tcp --dport  -j ACCEPT #本实验需要改为6030
-A INPUT -m state --state NEW -m tcp -p tcp --dport  -j ACCEPT #本实验需要改为6031

setenforce 

 

二、下载安装，在node1,node2,node3分别进行如下安装

yum install -y  http://www.percona.com/downloads/percona-release/redhat/0.1-3/percona-release-0.1-3.noarch.rpm
yum install -y perl-DBD-MySQL.x86_64 perl-IO-Socket-SSL.noarch socat.x86_64 nc
yum install -y  openssl openssl-devel

#step  prepare :5.6. needs libssl.so. libcrypto.so. ()
cd /usr/lib64
ln -s libssl.so.1.0.1e libssl.so.
ln -s  libcrypto.so.1.0.1e libcrypto.so.

#step2:download pxc
cd /usr/local/src
wget https://www.percona.com/downloads/Percona-XtraDB-Cluster-56/Percona-XtraDB-Cluster-5.6.26-25.12/binary/tarball/Percona-XtraDB-Cluster-5.6.26-rel74.0-25.12.1.Linux.x86_64.tar.gz
cd /usr/local
mv Percona-XtraDB-Cluster-5.6.-rel74.-25.12..Linux.x86_64.tar.gz pxc_56

#step3:install pxc
cd /usr/local/pxc_56
 ./scripts/mysql_install_db --defaults-file=/home/mysql/my6000.cnf --basedir=/usr/local/pxc_56

  chown -R mysql. /home/mysql

  chown -R mysql. /usr/local/pxc_56

 配置文件：my6000.cnf

[client]
port            = 6000
socket          = /home/mysql/I6000/mysql.sock
default-character-set=utf8

[mysqld]
basedir = /usr/local/pxc_56
datadir = /home/mysql/I6000

pid-file        = /home/mysql/I6000/mysql.pid
character-set-server=utf8
init_connect = 'SET NAMES utf8'
log-bin=/home/mysql/I6000/log_bin
server-id = 9816000

innodb_buffer_pool_size = 100M
innodb_data_file_path = ibdata1:10M:autoextend
innodb_data_home_dir = /home/mysql/I6000
innodb_file_per_table=1

skip-name-resolve

port            = 6000
socket          = /home/mysql/I6000/mysql.sock
user=mysql
log_error=/home/mysql/I6000/mysql_error.log

#pxc
user=mysql
log_error=error.log
binlog_format=ROW

#6000 for mysqld port, 6020 for sst port, 6031 for ist port, 6030 for cluster communication port 端口作用及说明见上面
wsrep_cluster_address='gcomm://192.168.1.81:6030,192.168.1.238:6030,192.168.1.240:6030' #三个节点都保持一样
wsrep_provider=/usr/local/pxc_56/lib/libgalera_smm.so
wsrep_sst_receive_address=192.168.1.238:6020  #根据不同的node ip进行修改
wsrep_node_incoming_address=192.168.1.238:6000  #根据不同的node ip进行修改
wsrep_node_address=192.168.1.238:6000  #根据不同的node ip进行修改
wsrep_provider_options = "gmcast.listen_addr=tcp://192.168.1.238:6030;ist.recv_addr=192.168.1.238:6031;"  #根据不同的node ip进行修改

wsrep_slave_threads=2
wsrep_cluster_name=pxc_zejin   #同一个cluster此值需要一致
wsrep_sst_method=xtrabackup-v2
wsrep_node_name=node6000_238  #不同节点修改为不同的名字
innodb_autoinc_lock_mode=2
wsrep_sst_auth="sstuser:123"
log-slave-updates

[mysql]
no-auto-rehash
default-character-set=utf8

 三、实例启动：

#安装实例
/usr/local/pxc_56/scripts/mysql_install_db --defaults-file=/home/mysql/my6000.cnf --basedir=/usr/local/pxc_56
#启动第一个实例
/usr/local/pxc_56/bin/mysqld_safe --defaults-file=/home/mysql/my6000.cnf --ledir=/usr/local/pxc_56/bin/ --wsrep-new-cluster  &
#修改密码
/usr/local/pxc_56/bin/mysqladmin -u root -P6000 password '' -S /home/mysql/I6000/mysql.sock
#登陆并增加用户
/usr/local/pxc_56/bin/mysql -uroot -p -P6000 -S /home/mysql/I6000/mysql.sock
grant all on *.* to 'sstuser'@'localhost' identified by '';
flush privielges;

mysql> show global status like 'wsrep_cluster_size';
+--------------------+-------+
| Variable_name      | Value |
+--------------------+-------+
| wsrep_cluster_size |      |
+--------------------+-------+
 row in set (0.00 sec)

四、启动第二、三个node

#不需要加--wsrep-new-cluster
/usr/local/pxc_56/bin/mysqld_safe --defaults-file=/home/mysql/I6000/my6000.cnf --ledir=/usr/local/pxc_56/bin/ & 

整个过程大约如下：

   1.决断是否可以IST

   2.不可以的话Requesting state transfer

   3.Cleaning the existing datadir and innodb-data/log directories 会将之前实例的内容全部删除。#所以不能将my6000.cnf文件放在与datadir目录下，要不会被删除，并且在重新启动服务时出错

   4.Waiting for SST streaming to complete

   5.启动服务。

 

  官方说明：

    XtraBackup SST works in two stages:
      • Stage I on joiner checks if it is SST or IST based on presence of xtrabackup_ist file.
      • In Stage II it starts the data transfer, if it’s SST, it empties the data directory sans few files (galera.cache, sst_in_progress, grastate.dat) and then proceed with the SST or if it’s IST, proceeds as before.

加入成功：
:: root@127.0.0.1:[test] >show global status like 'wsrep_cluster_size';
+--------------------+-------+
| Variable_name      | Value |
+--------------------+-------+
| wsrep_cluster_size |      |
+--------------------+-------+
 row in set (0.00 sec)

五、操作过程中经常用到的命令：

安装：/usr/local/pxc_56/scripts/mysql_install_db --defaults-file=/home/mysql/my6000.cnf --basedir=/usr/local/pxc_56
启动：/usr/local/pxc_56/bin/mysqld_safe --defaults-file=/home/mysql/my6000.cnf --ledir=/usr/local/pxc_56/bin/ &  ( 第一个节点要加上--wsrep-new-cluster )
登陆：/usr/local/pxc_56/bin/mysql -uroot -p -P6000 -S /home/mysql/I6000/mysql.sock
关闭：/usr/local/pxc_56/bin/mysqladmin -uroot -p -P6000 -S /home/mysql/I6000/mysql.sock  shutdown

 

 

六、安装过程中可能遇到的问题：

 

A.

节点启动时：
/usr/local/pxc_56/bin/mysqld_safe --defaults-file=/home/mysql/my3307.cnf --ledir=/usr/local/pxc_56/bin/ &
有可能启动会提示：
WSREP_SST: [ERROR] socat not found in path: /usr/sbin:/sbin:/usr/local/pxc_56//bin:/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/opt/lamp/mysql/bin:/root/bi
n ( ::04.404)
-- ::  [ERROR] WSREP: Failed to read 'ready <addr>' from: wsrep_sst_xtrabackup-v2 --role 'joiner' --address '192.168.1.238' --datadir '/home/mysql/I3307/
' --defaults-file '/home/mysql/I3307/my3307.cnf' --defaults-group-suffix '' --parent ''  ''
        Read: '(null)'
-- ::  [ERROR] WSREP: Process completed with error: wsrep_sst_xtrabackup-v2 --role 'joiner' --address '192.168.1.238' --datadir '/home/mysql/I3307/' --de
faults-file '/home/mysql/I3307/my3307.cnf' --defaults-group-suffix '' --parent ''  '' :  (No such file or directory)
-- ::  [ERROR] WSREP: Failed to prepare for 'xtrabackup-v2' SST. Unrecoverable.
-- ::  [ERROR] Aborting

原因及解决方法：socat 没有安装到，之前源包没有，可以进行如下安装：

wget --no-cache http://www.convirture.com/repos/definitions/rhel/6.x/convirt.repo -O /etc/yum.repos.d/convirt.repo

yum install socat

 

 

B.

第一个节点如果直接这样启动：
/usr/local/pxc_56/bin/mysqld_safe --defaults-file=/home/mysql/my6000.cnf &

在errorlog里面会出现：
-- ::  [ERROR] WSREP: failed to open gcomm backend connection: : failed to reach primary view:  (Connection timed out)
         at gcomm/src/pc.cpp:connect():
-- ::  [ERROR] WSREP: gcs/src/gcs_core.cpp:gcs_core_open():: Failed to open backend connection: - (Connection timed out)
-- ::  [ERROR] WSREP: gcs/src/gcs.cpp:gcs_open():: Failed to open channel 'pxc_zejin' at 'gcomm://192.168.1.240,192.168.1.238,192.168.1.81': - (Con
nection timed out)
-- ::  [ERROR] WSREP: gcs connect failed: Connection timed out
-- ::  [ERROR] WSREP: wsrep::connect(gcomm://192.168.1.240,192.168.1.238,192.168.1.81) failed: 7
-- ::  [ERROR] Aborting

-- ::  [Note] WSREP: Service disconnected.
-- ::  [Note] WSREP: Some threads may fail to exit.
-- ::  [Note] Binlog end
-- ::  [Note] /usr/local/pxc_56/bin/mysqld: Shutdown complete

解决方法：第一个节点启动要加上：--wsrep-new-cluster

/usr/local/pxc_56/bin/mysqld_safe --defaults-file=/home/mysql/my6000.cnf --ledir=/usr/local/pxc_56/bin --wsrep-new-cluster  &

 

 

 C.

#第二个节点或第三个节点启动报错：
WSREP_SST: [ERROR] Cleanup after exit with status: ( ::50.483)
-- ::  [ERROR] WSREP: Process completed with error: wsrep_sst_xtrabackup-v2 --role 'joiner' --address '192.168.1.240:6020' --datadir '/home/mysql/I6000/'
 --defaults-file '/home/mysql/I6000/my6000.cnf' --defaults-group-suffix '' --parent ''  '' :  (Operation not permitted)
-- ::  [ERROR] WSREP: Failed to read uuid:seqno from joiner script.
-- ::  [ERROR] WSREP: SST script aborted with error  (Operation not permitted)
-- ::  [ERROR] WSREP: SST failed:  (Operation not permitted)
-- ::  [ERROR] Aborting

原因及解决方法：配置文件my6000.cnf放在与datadir目录下，在Cleaning the existing datadir阶段被删除，在重启服务时就会找不到配置文件，在重新启动服务就会出错，把配置文件放在非datadir目录下即可。如/etc/my6000.cnf