MySQL多主复制-MySQL Galera安装部署

原文转自http://www.360doc.com/content/17/1124/09/50043420_706660592.shtml，只作为自己留存学习。

MySQL Galera介绍

• 特性简介

  MySQL/Galera是MySQL/InnoDB的多主集群,有以下特性: - 同步复制 - Active-active的多主拓扑结构 - 集群任意节点可以读和写 - 自动身份控制,失败节点自动脱离集群 - 自动节点接入 - 真正的基于”行”级别和ID检查的并行复制 - 无单点故障,易扩展

• 

MySQL Galera安装

• 安装前准备

  • 机器准备 G221 : 192.168.1.221 (Centos 6.5) G222 : 192.168.1.222 (Centos 6.5) G223 : 192.168.1.223 (Centos 6.5)

安装依赖
- 确认安装有gcc和gcc-c++的版本为至少4.4

# yum install gcc gcc-c++

- 确认安装有boost-devel的版本至少为1.4.1

# yum install boost-devel

- 安装scons check-devel openssl-devel

# yum install scons check-devel openssl-devel

• MySQL Galera安装

  • 安装含wsrep Patch的MySQL 5.5.29

    # yum install libaio
    # wget https://launchpad.net/codership-mysql/5.5/5.5.29-23.7.3/+download/mysql-5.5.29_wsrep_23.7.3-linux-x86_64.tar.gz
    # tar zxvf mysql-5.5.29_wsrep_23.7.3-linux-x86_64.tar.gz 
    # # mv mysql-5.5.29_wsrep_23.7.3-linux-x86_64 /usr/local/mysql
    # cd /usr/local/mysql/
    # groupadd mysql
    # useradd -r -g mysql mysql
    # chown -R mysql:mysql .
    # ./scripts/mysql_install_db --no-defaults --datadir=/usr/local/mysql/data --user=mysql
    # chown -R root .
    # chown -R mysql data

  • 安装Galera复制插件

    # wget https://launchpad.net/galera/2.x/23.2.4/+download/galera-23.2.4-src.tar.gz
    # tar zxvf galera-23.2.4-src.tar.gz
    # cd galera-23.2.4-src
    # scons
    # cp garb/garbd /usr/local/mysql/bin/
    # cp libgalera_smm.so /usr/local/mysql/lib/plugin/

• MySQL Galera配置

  • MySQL Galera配置例子:

    # cp /usr/local/mysql/support-files/mysql.server /etc/init.d/mysql
    # mkdir -p /var/lib/mysql
    # chown mysql:mysql /var/lib/mysql
    # vi /etc/my.cnf
    # cat /etc/my.cnf

    [client]
    port = 3306
    socket = /var/lib/mysql/mysql.sock
    
    [mysqld_safe]
    log-error = /var/lib/mysql/mysql.log
    pid-file = /var/lib/mysql/mysql.pid
    
    [mysqld]
    wsrep_node_name = node1
    wsrep_provider = /usr/local/mysql/lib/plugin/libgalera_smm.so
    #wsrep_provider_options ='gcache.size=1G;socket.ssl_key=my_key;socket.ssl_cert=my_cert'
    #wsrep_slave_threads=16
    wsrep_sst_method = rsync
    #wsrep_sst_auth=root:
    
    port = 3306
    socket = /var/lib/mysql/mysql.sock
    user = mysql
    basedir = /usr/local/mysql
    datadir = /usr/local/mysql/data
    
    default_storage_engine=InnoDB
    #innodb_buffer_pool_size=1G
    #innodb_log_file_size=256M
    innodb_autoinc_lock_mode=2
    innodb_locks_unsafe_for_binlog=1
    innodb_flush_log_at_trx_commit=0
    innodb_doublewrite=0
    innodb_file_per_table=1
    
    binlog_format=ROW
    log-bin=mysql-bin
    server-id=101
    relay-log=mysql-relay-bin
    #read_only=1
    log-slave-updates=1

• MySQL Galera启动与关闭

  • 初次启动:

    [root@G221 ~]# /usr/local/mysql/bin/mysqld_safe --wsrep_cluster_address=gcomm:// >/dev/null &

    或

    [root@G221 ~]# service mysql start --wsrep_cluster_address=gcomm://

    查看mysqld监听的端口:

    [root@G221 ~]# netstat -plantu | grep mysqld
    tcp        0      0 0.0.0.0:4567       0.0.0.0:*          LISTEN      3656/mysqld         
    tcp        0      0 0.0.0.0:3306       0.0.0.0:*          LISTEN      3656/mysqld

    注:
    1)”gcomm://”是特殊的地址,仅仅是galera cluster初始化启动时候使用,再次启动的时候需要使用具体的IP地址.
    2) 端口4567是wsrep使用的默认端口.该端口的防火墙设置规则应该和3306的一样.

  • 关闭:

    [root@G221 ~]# /usr/local/mysql/bin/mysqladmin -uroot -p shutdown

MySQL Galera新节点

• 添加新节点

• 节点接入
  添加新节点的时候,新接入的节点叫Joiner,给joiner提供复制的节点叫Donor.新的节点接入需要:
  1) 安装带wsrep patch的MySQL版本
  2) 安装Galera复制插件
  3) 配置好新节点的MySQL(参考Donnor的my.cnf)
  4) 配置或启动的gcomm://的地址是需要使用donnor的IP.

  接入节点G222:

  [root@G222 data]# /usr/local/mysql/bin/mysqld_safe --wsrep_cluster_address="gcomm://192.168.1.221:4567,192.168.1.223:4567"    >/dev/null &

• 接入节点G223:

  [root@G223 data]# service mysql start --wsrep_cluster_address="gcomm://192.168.1.221:4567,192.168.1.222:4567"

• 修改节点的wsrep_cluster_address修改wsrep_cluster_address有两种方式:1)使用新的wsrep_cluster_address重启节点:

  [root@G221 data]# service mysql restart --wsrep_cluster_address="gcomm://192.168.1.222:4567,192.168.1.223:4567"
  Shutting down MySQL.... SUCCESS! 
  Starting MySQL....... SUCCESS!

  2)直接修改MySQL全局变量

  mysql> SHOW VARIABLES LIKE 'wsrep_cluster_address';
  +-----------------------+----------------------------+
  | Variable_name         | Value                      |
  +-----------------------+----------------------------+
  | wsrep_cluster_address | gcomm://192.168.1.222:4567 |
  +-----------------------+----------------------------+
  1 row in set (0.00 sec)
  
  mysql> set global wsrep_cluster_address="gcomm://192.168.1.222:4567,192.168.1.223:4567";
  Query OK, 0 rows affected (2.20 sec)
  
  mysql> SHOW VARIABLES LIKE 'wsrep_cluster_address';
  +-----------------------+-------------------------------------------------------+
  | Variable_name         | Value                                                 |
  +-----------------------+-------------------------------------------------------+
  | wsrep_cluster_address | gcomm://192.168.1.222:4567,192.168.1.223:4567 |
  +-----------------------+-------------------------------------------------------+
  1 row in set (0.00 sec)

MySQL Galera监控

• 查看相关变量

• 查看MySQL版本:

  mysql> SHOW GLOBAL VARIABLES LIKE 'version';
  +---------------+------------+
  | Variable_name | Value      |
  +---------------+------------+
  | version       | 5.5.29-log |
  +---------------+------------+
  1 row in set (0.00 sec)

  查看wsrep版本:

  mysql> SHOW GLOBAL STATUS LIKE 'wsrep_provider_version';
  +------------------------+------------+
  | Variable_name          | Value      |
  +------------------------+------------+
  | wsrep_provider_version | 2.4(rXXXX) |
  +------------------------+------------+
  1 row in set (0.00 sec)

mysql> SHOW VARIABLES LIKE 'wsrep_cluster_address';
+-----------------------+-------------------------------------------------------+
| Variable_name         | Value                                                 |
+-----------------------+-------------------------------------------------------+
| wsrep_cluster_address | gcomm://192.168.1.222:4567,192.168.1.223:4567 |
+-----------------------+-------------------------------------------------------+
1 row in set (0.00 sec)

• 查看Galera集群状态:

  mysql> show status like 'wsrep%';
  +----------------------------+----------------------------------------------------------+
  | Variable_name              | Value                                                    |
  +----------------------------+----------------------------------------------------------+
  | wsrep_local_state_uuid     | 80cdd13d-8cf2-11e2-0800-e0817023b754                     |
  | wsrep_protocol_version     | 4                                                        |
  | wsrep_last_committed       | 3                                                        |
  | wsrep_replicated           | 3                                                        |
  | wsrep_replicated_bytes     | 522                                                      |
  | wsrep_received             | 6                                                        |
  | wsrep_received_bytes       | 1134                                                     |
  | wsrep_local_commits        | 1                                                        |
  | wsrep_local_cert_failures  | 0                                                        |
  | wsrep_local_bf_aborts      | 0                                                        |
  | wsrep_local_replays        | 0                                                        |
  | wsrep_local_send_queue     | 0                                                        |
  | wsrep_local_send_queue_avg | 0.000000                                                 |
  | wsrep_local_recv_queue     | 0                                                        |
  | wsrep_local_recv_queue_avg | 0.000000                                                 |
  | wsrep_flow_control_paused  | 0.000000                                                 |
  | wsrep_flow_control_sent    | 0                                                        |
  | wsrep_flow_control_recv    | 0                                                        |
  | wsrep_cert_deps_distance   | 1.000000                                                 |
  | wsrep_apply_oooe           | 0.000000                                                 |
  | wsrep_apply_oool           | 0.000000                                                 |
  | wsrep_apply_window         | 1.000000                                                 |
  | wsrep_commit_oooe          | 0.000000                                                 |
  | wsrep_commit_oool          | 0.000000                                                 |
  | wsrep_commit_window        | 1.000000                                                 |
  | wsrep_local_state          | 4                                                        |
  | wsrep_local_state_comment  | Synced                                                   |
  | wsrep_cert_index_size      | 5                                                        |
  | wsrep_causal_reads         | 0                                                        |
  | wsrep_incoming_addresses   | 192.168.1.221:3306,192.168.1.222:3306,192.168.1.223:3306 |
  | wsrep_cluster_conf_id      | 13                                                       |
  | wsrep_cluster_size         | 3                                                        |
  | wsrep_cluster_state_uuid   | 80cdd13d-8cf2-11e2-0800-e0817023b754                     |
  | wsrep_cluster_status       | Primary                                                  |
  | wsrep_connected            | ON                                                       |
  | wsrep_local_index          | 0                                                        |
  | wsrep_provider_name        | Galera                                                   |
  | wsrep_provider_vendor      | Codership Oy                         |
  | wsrep_provider_version     | 2.4(rXXXX)                                               |
  | wsrep_ready                | ON                                                       |
  +----------------------------+----------------------------------------------------------+
  40 rows in set (0.00 sec)

• 监控状态说明

  • 集群完整性检查:
    • wsrep_cluster_state_uuid:在集群所有节点的值应该是相同的,有不同值的节点,说明其没有连接入集群.
    • wsrep_cluster_conf_id:正常情况下所有节点上该值是一样的.如果值不同,说明该节点被临时”分区”了.当节点之间网络连接恢复的时候应该会恢复一样的值.
    • wsrep_cluster_size:如果这个值跟预期的节点数一致,则所有的集群节点已经连接.
    • wsrep_cluster_status:集群组成的状态.如果不为”Primary”,说明出现”分区”或是”split-brain”状况.
  • 节点状态检查:
    • wsrep_ready: 该值为ON,则说明可以接受SQL负载.如果为Off,则需要检查wsrep_connected.
    • wsrep_connected: 如果该值为Off,且wsrep_ready的值也为Off,则说明该节点没有连接到集群.(可能是wsrep_cluster_address或wsrep_cluster_name等配置错造成的.具体错误需要查看错误日志)
    • wsrep_local_state_comment:如果wsrep_connected为On,但wsrep_ready为OFF,则可以从该项查看原因.
  • 复制健康检查:
    • wsrep_flow_control_paused:表示复制停止了多长时间.即表明集群因为Slave延迟而慢的程度.值为0~1,越靠近0越好,值为1表示复制完全停止.可优化wsrep_slave_threads的值来改善.
    • wsrep_cert_deps_distance:有多少事务可以并行应用处理.wsrep_slave_threads设置的值不应该高出该值太多.
    • wsrep_flow_control_sent:表示该节点已经停止复制了多少次.
    • wsrep_local_recv_queue_avg:表示slave事务队列的平均长度.slave瓶颈的预兆.

    最慢的节点的wsrep_flow_control_sent和wsrep_local_recv_queue_avg这两个值最高.这两个值较低的话,相对更好.

  • 检测慢网络问题:
    • wsrep_local_send_queue_avg:网络瓶颈的预兆.如果这个值比较高的话,可能存在网络瓶
  • 冲突或死锁的数目:
    • wsrep_last_committed:最后提交的事务数目
    • wsrep_local_cert_failures和wsrep_local_bf_aborts:回滚,检测到的冲突数

MySQL Galera其它特性

• Galera arbitrator

  garbd可以做为一个无数据的Galera节点运行,该节点可以用一种优化的方式帮助检测和处理网络分裂(network splits).
  一个好的garbd节点可以防止”split-brain”状况发生.

• SSL支持

  Galera支持SSL通讯,这对增加数据安全性很重要(特别是云部署).可以通过参数socket.ssl_cert和socket.ssl_key来定义.

• SST方式选择

  SST允许新接入的节点使用定制的方法来获取最初的数据.SST方式有mysqldump(默认,比较慢),rsync,和xtrabackup(很快).
  可通过wsrep_sst_method来定义.Production环境中建议使用rsync或是xtrabackup方式.