mysql主從搭建

一主單從
步驟：


1、配置master主機的my.cnf，配置內容如下：




[mysqld]
user=mysql
pid-file=/var/run/mysqld/mysqld.pid
socket=/var/run/mysqld/mysqld.sock
port=3306
basedir=/usr
datadir=/var/lib/mysql
tmpdir=/tmp
log-bin=master-bin
log-bin-index=master-bin.index
server-id=1


配置完之後重啟，使my.cnf生效


建立複製使用者，並賦予replication slave許可權給slave節點


mysql> create user repl_user;


mysql> grant replication slave on *.* to repl_user@mt identified by xyzzy;




2、配置slave從機的my.cnf，配置內容如下：


[mysqld]
user=mysql
pid-file=/var/run/mysqld/mysqld.pid
socket=/var/run/mysqld/mysqld.sock
port=3306
basedir=/usr
datadir=/var/lib/mysql
tmpdir=/tmp
server-id=2
relay-log-index=slave-relay-bin.index
relay-log=slave-relay-bin




在slave上配置slave與master的連線




change master to 
master_host='mo',
master_port='3306',
master_user'repl_user',
master_password='xyzzy',
master_log_file='mysql-bin.00002', 
master_log_pos=101;




啟動slave


start slave




3、檢視slave的狀態


mysql> show slave status \G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: mo
                  Master_User: repl_user
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: master-bin.000001
          Read_Master_Log_Pos: 946
               Relay_Log_File: slave-relay-bin.000002
                Relay_Log_Pos: 1092
        Relay_Master_Log_File: master-bin.000001
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
              Replicate_Do_DB: 
          Replicate_Ignore_DB: 
           Replicate_Do_Table: 
       Replicate_Ignore_Table: 
      Replicate_Wild_Do_Table: 
  Replicate_Wild_Ignore_Table: 
                   Last_Errno: 0
                   Last_Error: 
                 Skip_Counter: 0
          Exec_Master_Log_Pos: 946
              Relay_Log_Space: 1247
              Until_Condition: None
               Until_Log_File: 
                Until_Log_Pos: 0
           Master_SSL_Allowed: No
           Master_SSL_CA_File: 
           Master_SSL_CA_Path: 
              Master_SSL_Cert: 
            Master_SSL_Cipher: 
               Master_SSL_Key: 
        Seconds_Behind_Master: 0
Master_SSL_Verify_Server_Cert: No
                Last_IO_Errno: 0
                Last_IO_Error: 
               Last_SQL_Errno: 0
               Last_SQL_Error: 
1 row in set (0.00 sec)


如果Slave_IO_Running、Slave_SQL_Running均為yes則證明配置成功，如果有其中一個為no，如下所示：


mysql> show slave status \G
*************************** 1. row ***************************
               Slave_IO_State: Connecting to master
                  Master_Host: mo
                  Master_User: repl_user
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: 
          Read_Master_Log_Pos: 4
               Relay_Log_File: slave-relay-bin.000001
                Relay_Log_Pos: 4
        Relay_Master_Log_File: 
             Slave_IO_Running: No
            Slave_SQL_Running: Yes
              Replicate_Do_DB: 
          Replicate_Ignore_DB: 
           Replicate_Do_Table: 
       Replicate_Ignore_Table: 
      Replicate_Wild_Do_Table: 
  Replicate_Wild_Ignore_Table: 
                   Last_Errno: 0
                   Last_Error: 
                 Skip_Counter: 0
          Exec_Master_Log_Pos: 0
              Relay_Log_Space: 106
              Until_Condition: None
               Until_Log_File: 
                Until_Log_Pos: 0
           Master_SSL_Allowed: No
           Master_SSL_CA_File: 
           Master_SSL_CA_Path: 
              Master_SSL_Cert: 
            Master_SSL_Cipher: 
               Master_SSL_Key: 
        Seconds_Behind_Master: NULL
Master_SSL_Verify_Server_Cert: No
                Last_IO_Errno: 2013
                Last_IO_Error: error connecting to master 'repl_user@mo:3306' - retry-time: 60  retries: 86400
               Last_SQL_Errno: 0
               Last_SQL_Error: 
1 row in set (0.00 sec)


則檢視Last_IO_Errno、Last_IO_Error引數，和datadir目錄下的hostname.err檔案找出錯誤日誌資訊，如下所示


[root@mt ~]# cd /var/lib/mysql/
[root@mt mysql]# ls
ibdata1  ib_logfile0  ib_logfile1  master.info  mt.err  mysql  relay-log.info  slave-relay-bin.000001  slave-relay-bin.index  test
[root@mt mysql]# cd mt.err 
-bash: cd: mt.err: Not a directory
[root@mt mysql]# tail -f n 200 mt.err 
tail: cannot open `n' for reading: No such file or directory
tail: cannot open `200' for reading: No such file or directory
==> mt.err <==
160731 19:27:43  InnoDB: Initializing buffer pool, size = 8.0M
160731 19:27:43  InnoDB: Completed initialization of buffer pool
160731 19:27:43  InnoDB: Started; log sequence number 0 44233
160731 19:27:43 [Note] Event Scheduler: Loaded 0 events
160731 19:27:43 [Note] /usr/libexec/mysqld: ready for connections.
Version: '5.1.71'  socket: '/var/run/mysqld/mysqld.sock'  port: 3306  Source distribution
160731 19:47:02 [Note] 'CHANGE MASTER TO executed'. Previous state master_host='', master_port='3306', master_log_file='', master_log_pos='4'. New state master_host='mo', master_port='3306', master_log_file='', master_log_pos='4'.
160731 19:47:09 [Note] Slave SQL thread initialized, starting replication in log 'FIRST' at position 0, relay log './slave-relay-bin.000001' position: 4
160731 19:47:09 [ERROR] Slave I/O: error connecting to master 'repl_user@mo:3306' - retry-time: 60  retries: 86400, Error_code: 2005
160731 21:13:09 [ERROR] Slave I/O: error connecting to master 'repl_user@mo:3306' - retry-time: 60  retries: 86400, Error_code: 2013






上述錯誤為repl_user沒有給slave機replication slave許可權


可以檢視
select user,host,password from mysql.user;
看到user在哪個host上可以登陸，如果repl_user對應的host沒有slave節點對應的主機名，則repl_user使用者無法在slave機上進行遠端連線到master所在的節點機。




可以使用show binary logs檢視logbin的日誌資訊


可以使用show master status \G 檢視主節點資訊