CDH的mysql主从准备

参考:

https://www.cnblogs.com/yinzhengjie/p/10371899.html

https://www.sysit.cn/blog/post/sysit/CDH6.2.0%E7%B3%BB%E7%BB%9F%E9%83%A8%E7%BD%B2%E6%89%8B%E5%86%8C

搭建主库: CM节点

mysql> status;

Server version:5.7.27 MySQL Community Server (GPL)

#配置源

cat > /etc/yum.repos.d/mysql-community-el7.repo<<'EOF'

[mysql57-community]

name=MySQL 5.7 Community Server

baseurl=http://mirror.tuna.tsinghua.edu.cn/mysql/yum/mysql57-community-el7/

enabled=1

gpgcheck=0

EOF

# 安装

yum install mysql-community-server -y

echo "character-set-server=utf8" >>/etc/my.cnf

systemctl restart mysqld

# mysqld.log中查询密码

grep password /var/log/mysqld.log

2019-04-09T07:28:44.292450Z 1 [Note] A temporary password is generated for root@localhost: wg:V45ci4ljpz!r

#注意,安装CDH最好用官方推进的my.cnf文件,见下附录.

# 测试环境关闭强策略密码，生产环境建议开启。不关闭只支持mysql -uslave -P 3306 -h10.52.2.128 -p的登陆方式

echo "validate-password=off" >>/etc/my.cnf

echo "server-id=101"  >> /etc/my.cnf

echo "log-bin=mysql-bin" >>  /etc/my.cnf                 #开启日志做主从,不然show master status时会是空的.

# 重启mysql

systemctl restart mysqld

# 重置安全配置

mysql_secure_installation

# 登录mysql

mysql -uroot -p

#此时需要用到上面的密码

#登陆后修改成自己的密码:

mysql> alter user user() identified by 'test123456';

#检查

datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock

symbolic-links=0

log-error=/var/log/mysqld.log
#pid-file=/var/run/mysqld/mysqld.pid
character-set-server=utf8
validate-password=off
server-id=101

#查看当前服务器的server_id

mysql> show variables like '%server_id%';

#查bin_log是否开启

mysql> show variables like '%log_bin%';
+---------------------------------+-------+
| Variable_name | Value |
+---------------------------------+-------+
| log_bin | ON
---------------------

#查看授权情况

select user,host from mysql.user;

附录：cloudera官方推荐

[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
transaction-isolation = READ-COMMITTED
# Disabling symbolic-links is recommended to prevent assorted security risks;
# to do so, uncomment this line:
symbolic-links = 0

key_buffer_size = 32M
max_allowed_packet = 32M
thread_stack = 256K
thread_cache_size = 64
query_cache_limit = 8M
query_cache_size = 64M
query_cache_type = 1

max_connections = 550
#expire_logs_days = 10
#max_binlog_size = 100M

#log_bin should be on a disk with enough free space.
#Replace '/var/lib/mysql/mysql_binary_log' with an appropriate path for your
#system and chown the specified folder to the mysql user.
log_bin=/var/lib/mysql/mysql_binary_log                 #开启bin_log

#In later versions of MySQL, if you enable the binary log and do not set
#a server_id, MySQL will not start. The server_id must be unique within
#the replicating group.
server_id=1

binlog_format = mixed

read_buffer_size = 2M
read_rnd_buffer_size = 16M
sort_buffer_size = 8M
join_buffer_size = 8M

# InnoDB settings
innodb_file_per_table = 1
innodb_flush_log_at_trx_commit = 2
innodb_log_buffer_size = 64M
innodb_buffer_pool_size = 4G
innodb_thread_concurrency = 8
innodb_flush_method = O_DIRECT
innodb_log_file_size = 512M

[mysqld_safe]
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid

sql_mode=STRICT_ALL_TABLES

在另一个节点上搭建从库:

操作同上, server-id=102要不同

mysql> show variables like '%server_id%';

配置主从同步:

#在主库上授权copy帐号用于复制,密码是fengfeng99
[root@node106.fengfeng.org.cn ~]# mysql -uroot -p

mysql> CREATE USER 'copy'@'195.189.142.83%' IDENTIFIED BY 'fengfeng99';
Query OK, 0 rows affected (0.01 sec)

mysql> GRANT REPLICATION SLAVE ON *.* TO 'copy'@'195.189.142.83%';
Query OK, 0 rows affected (0.00 sec)

mysql> quit

检查:
#在从库节点上用copy用户远程:
mysql -u copy -pfengfeng99 -P 3306 -h195.189.142.89
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
+--------------------+
1 row in set (0.00 sec)

#获取主库的日志信息并生成主库数据镜像,主库上:

mysql> FLUSH TABLES WITH READ LOCK;　　　　　　　　　　　　　　　　　　#对主库上所有表加锁，停止修改，即在从库复制的过程中主库不能执行UPDATA，DELETE，INSERT语句！
Query OK, 0 rows affected (0.00 sec)

mysql> SHOW MASTER STATUS; 　　　　　　　　　　　　　　　　　　 #获取主库的日志信息，file表示当前日志文件名称，position表示当前日志的位置
mysql> SHOW MASTER STATUS;
+------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000001 | 154 | | | |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
mysql> quit

[root@zhep-opay-temp-1 ~]# mysqldump --all-databases --master-data -u root -pfengfeng99 -P 3306 > fengfeng-master.db 　#另开一个终端生成镜像，在生成完成之前不要释放锁。
mysqldump: [Warning] Using a password on the command line interface can be insecure.
[root@zhep-opay-temp-1 ~]# ls
anaconda-ks.cfg fengfeng-master.db original-ks.cfg test.log

mysql> UNLOCK TABLES;　　　　　　#主库数据生成镜像完毕后，我们需要把主库的锁释放掉，需要注意的是，在上锁这一段期间，我们无法对数据库进行写操作，比如UPDATA，DELETE，INSERT。
Query OK, 0 rows affected (0.00 sec)

将主库的镜像拷贝到从库服务器，让从库应用主库镜像
[root@zhep-opay-temp-1 ~]# scp fengfeng-master.db 195.189.142.83:~
fengfeng-master.db

登陆从库:

mysql> source fengfeng-master.db;
Query OK, 0 rows affected (0.00 sec)

Query OK, 0 rows affected (0.00 sec)

Query OK, 0 rows affected (0.00 sec)

Query OK, 0 rows affected (0.00 sec)

#在从库上建立复制关系，即从库指定主库的日志信息和链接信息
mysql>
CHANGE MASTER TO
MASTER_HOST='195.189.142.89',
MASTER_PORT=3306,
MASTER_USER='copy',
MASTER_PASSWORD='fengfeng99',
MASTER_LOG_FILE='mysql-bin.000001',
MASTER_LOG_POS=154;

#MASTER_LOG_FILE是上面SHOW MASTER STATUS里的file, POS里面的position

mysql> START SLAVE;
Query OK, 0 rows affected (0.00 sec)

mysql>
mysql> SHOW SLAVE STATUS\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: node106.fengfeng.org.cn
Master_User: copy
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: fengfeng-mysql-bin.000002
Read_Master_Log_Pos: 4095
Relay_Log_File: node107-relay-bin.000002
Relay_Log_Pos: 332
Relay_Master_Log_File: fengfeng-mysql-bin.000002
Slave_IO_Running: Yes　　　　　#观察IO进程是否为yes，如果为yes说明正常，如果长时间处于"Connecting"状态就得检查你的从库指定的主库的链接信息是否正确
Slave_SQL_Running: Yes　　　　#观察SQL进程是否为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: 4095
Relay_Log_Space: 541
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　　　#该参数表示从库和主库有多少秒的延迟，咱们可以理解为再过多少秒数据和主库保持一致，如果为0表示当前从库和主库的数据是一致的，如果该数较大的话你得考虑它的合理性。需要注意下该参数的值。
Master_SSL_Verify_Server_Cert: No
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 0
Last_SQL_Error:
Replicate_Ignore_Server_Ids:
Master_Server_Id: 106
Master_UUID: 74227047-8b60-11e9-8cba-000c29985293
Master_Info_File: /fengfeng/softwares/mysql/data/master.info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
Master_Retry_Count: 86400
Master_Bind:
Last_IO_Error_Timestamp:
Last_SQL_Error_Timestamp:
Master_SSL_Crl:
Master_SSL_Crlpath:
Retrieved_Gtid_Set:
Executed_Gtid_Set:
Auto_Position: 0
Replicate_Rewrite_DB:
Channel_Name:
Master_TLS_Version:
1 row in set (0.00 sec)

#测试主从是否同步:
主库上建一个test库
mysql> CREATE DATABASE test DEFAULT CHARACTER SET = utf8;
Query OK, 1 row affected (1.82 sec)

mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| sys |
| test |
+--------------------+
5 rows in set (0.00 sec)

检查从库是否同步:
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| sys |
| test |
+--------------------+
5 rows in set (0.00 sec)

#也可在主库上建一张表,看是否同步:

create table student(
id int(4) not null AUTO_INCREMENT,
name char(20) not null,
age tinyint(2) NOT NULL default '0',
dept varchar(16) default NULL,
primary key(id),
KEY index_name (name)
);

#插入数据

insert into student(id,name) values(1,'oldboy');

#注:

锁库创建从库：即时在主库上拿一个完整备份，并恢复到新建的从库，优点：可以支持非事务引擎，
缺点：较慢，影响主库使用。
不锁库创建从库：拿主库最近一次可用的历史完整备份，先导数据，再追日志，优点：较为快速，不影响主库，缺点：不支持非事务引擎。

排错:

如果主从不同步.其它都不靠谱,靠谱的是在从库上stop slave; 按上面的方法重做一次.

可以先看错误日志,在: tail -1000 /var/log/mysqld.log

binglog的位置在my.cnf中的:log_bin=/var/lib/mysq

mysql> SHOW BINARY LOGS;
+-------------------------+-----------+
| Log_name | File_size |
+-------------------------+-----------+
| mysql_binary_log.000001 | 181956511 |
| mysql_binary_log.000002 | 526878457 |
| mysql_binary_log.000003 | 2055720 |
+-------------------------+-----------+
3 rows in set (0.00 sec)

#把从库设置成readonly

mysql> show global variables like "%read_only%";
+-----------------------+-------+
| Variable_name | Value |
+-----------------------+-------+
| innodb_read_only | OFF |
| read_only | OFF |
| super_read_only | OFF |
| transaction_read_only | OFF |
| tx_read_only | OFF |
+-----------------------+-------+
对于需要保证master-slave主从同步的salve库，如果要设置为只读状态，需要执行的命令为：
mysql> set global read_only=1;

将salve库从只读状态变为读写状态，需要执行的命令是：
mysql> set global read_only=0;

grant all on *.* to webdev@'localhost' identified by 'Test12345@';
grant select on *.* to webdev2@'localhost' identified by 'Test12345@';
grant select on *.* to webdev2@'%' identified by 'Test12345@';