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 3306 -j ACCEPT #本实验需要改为6000 -A INPUT -m state --state NEW -m tcp -p tcp --dport 4444 -j ACCEPT #本实验需要改为6020 -A INPUT -m state --state NEW -m tcp -p tcp --dport 4567 -j ACCEPT #本实验需要改为6030 -A INPUT -m state --state NEW -m tcp -p tcp --dport 4568 -j ACCEPT #本实验需要改为6031
setenforce 0
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 1 prepare :5.6.26 needs libssl.so.6 libcrypto.so.6 () cd /usr/lib64 ln -s libssl.so.1.0.1e libssl.so.6 ln -s libcrypto.so.1.0.1e libcrypto.so.6 #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-5.6.26-rel74.0-25.12.1.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 '000000' -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 '123'; flush privielges;
mysql> show global status like 'wsrep_cluster_size'; +--------------------+-------+ | Variable_name | Value | +--------------------+-------+ | wsrep_cluster_size | 1 | +--------------------+-------+ 1 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.
• 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： 07:49:13 root@127.0.0.1:[test] 6000>show global status like 'wsrep_cluster_size'; +--------------------+-------+ | Variable_name | Value | +--------------------+-------+ | wsrep_cluster_size | 3 | +--------------------+-------+ 1 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 (20160509 10:58:04.404) 2016-05-09 10:58:04 54809 [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 '54809' '' Read: '(null)' 2016-05-09 10:58:04 54809 [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 '54809' '' : 2 (No such file or directory) 2016-05-09 10:58:04 54809 [ERROR] WSREP: Failed to prepare for 'xtrabackup-v2' SST. Unrecoverable. 2016-05-09 10:58:04 54809 [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： 2016-05-09 09:49:46 9932 [ERROR] WSREP: failed to open gcomm backend connection: 110: failed to reach primary view: 110 (Connection timed out) at gcomm/src/pc.cpp:connect():162 2016-05-09 09:49:46 9932 [ERROR] WSREP: gcs/src/gcs_core.cpp:gcs_core_open():206: Failed to open backend connection: -110 (Connection timed out) 2016-05-09 09:49:46 9932 [ERROR] WSREP: gcs/src/gcs.cpp:gcs_open():1379: Failed to open channel 'pxc_zejin' at 'gcomm://192.168.1.240,192.168.1.238,192.168.1.81': -110 (Con nection timed out) 2016-05-09 09:49:46 9932 [ERROR] WSREP: gcs connect failed: Connection timed out 2016-05-09 09:49:46 9932 [ERROR] WSREP: wsrep::connect(gcomm://192.168.1.240,192.168.1.238,192.168.1.81) failed: 7 2016-05-09 09:49:46 9932 [ERROR] Aborting 2016-05-09 09:49:46 9932 [Note] WSREP: Service disconnected. 2016-05-09 09:49:47 9932 [Note] WSREP: Some threads may fail to exit. 2016-05-09 09:49:47 9932 [Note] Binlog end 2016-05-09 09:49:47 9932 [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:1 (20160509 19:25:50.483) 2016-05-09 19:25:50 44334 [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 '44334' '' : 1 (Operation not permitted) 2016-05-09 19:25:50 44334 [ERROR] WSREP: Failed to read uuid:seqno from joiner script. 2016-05-09 19:25:50 44334 [ERROR] WSREP: SST script aborted with error 1 (Operation not permitted) 2016-05-09 19:25:50 44334 [ERROR] WSREP: SST failed: 1 (Operation not permitted) 2016-05-09 19:25:50 44334 [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
