MariaDB加密复制测试

环境：

192.168.205.37: as master server
192.168.205.47: as middle server
192.168.205.57: as slave server

版本：

OS: centos 7 1810 with mini install
mariadb-5.5.60

目地：

有时我们的数据库复制可能要跨网络复制，如果不想在复制过程中让别人嗅探，我们可以使用ssl协议实现复制过程中数据的加密传输，此实验使用三台服务器实现半同步复制，并他复制之间启用加密复制

使用如下脚本安装三台主从服务器

1. 使用如下脚本安装三台服务器

   [root@centos7 data]#cat /data/maridb_yum.sh #!/bin/bash# use last digit of IP as server-idID=`ip a show dev eth0 | sed -r '3!d;s@(.*inet)(.*)(/.*)@\2@' | cut -d. -f4`# install mariadb-server and create data and logs directoryrpm -q mariadb-server ||yum install -y mariadb-server[ -d /data/mysql ] || mkdir -p /data/mysql[ -d /data/logs ] || mkdir -p /data/logschown mysql:mysql /data/{mysql,logs}# modify the my.cnf #设置数据文件位置sed -i 's@datadir=/var/lib/mysql@datadir=/data/mysql@' /etc/my.cnf #开启二进制日志并文件的起始名称sed -i 's@log-bin=mysql-bin@log-bin=/data/logs/bin@' /etc/my.cnf  #设置innodb表分离文件grep "innodb_file_per_table" /etc/my.cnf || sed -i '/\[mysqld\]/a innodb_file_per_table = on' /etc/my.cnf #跳过名称解析grep "skip_name_resolve" /etc/my.cnf || sed -i '/\[mysqld\]/a skip_name_resolve = on' /etc/my.cnf#将server-id设为eth0的IP的最后一位数，可跟据自己的需求更改grep "server-id" /etc/my.cnf || sed -i "/\[mysqld\]/a server-id=$ID" /etc/my.cnf#启动服务service mariadb restart

   主服务器的配置

2. 查看一下半同步插件的文件名称

   [root@slave1 ~]#rpm -ql mariadb-server…/usr/lib64/mysql/plugin/semisync_master.so/usr/lib64/mysql/plugin/semisync_slave.so…

3. 在主服务器上建立复制帐号

   MariaDB [(none)]> grant replication slave on *.* to repluser@'192.168.205.%' identified by 'centos';

4. 在主服务器上确定复制的位置

   MariaDB [(none)]> show master logs;+------------+-----------+| Log_name   | File_size |+------------+-----------+| bin.000001 |     30373 || bin.000002 |   1038814 || bin.000003 |      401 |+------------+-----------+3 rows in set (0.00 sec)

5. 主服务器上安装半同步插件

   MariaDB [(none)]> install plugin rpl_semi_sync_master soname 'semisync_master.so'; 

6. 查看半同步的变量

   MariaDB [(none)]> show global variables like '%semi%';+------------------------------------+-------+| Variable_name                      | Value |+------------------------------------+-------+| rpl_semi_sync_master_enabled       | OFF    || rpl_semi_sync_master_timeout       | 10000 || rpl_semi_sync_master_trace_level   | 32    || rpl_semi_sync_master_wait_no_slave | ON    |+------------------------------------+-------+4 rows in set (0.00 sec)

7. enable半同步复制

   MariaDB [(none)]> set global rpl_semi_sync_master_enabled=on

8. 查看半同步变量

   MariaDB [(none)]> show global variables like '%semi%';+------------------------------------+-------+| Variable_name                      | Value |+------------------------------------+-------+| rpl_semi_sync_master_enabled       | ON    || rpl_semi_sync_master_timeout       | 10000 || rpl_semi_sync_master_trace_level   | 32    || rpl_semi_sync_master_wait_no_slave | ON    |+------------------------------------+-------+4 rows in set (0.00 sec)

9. 查看半同步状态

   MariaDB [(none)]> show global status like '%semi%';+--------------------------------------------+-------+| Variable_name                              | Value |+--------------------------------------------+-------+| Rpl_semi_sync_master_clients               | 0    |  | Rpl_semi_sync_master_net_avg_wait_time     | 363   || Rpl_semi_sync_master_net_wait_time         | 25473 || Rpl_semi_sync_master_net_waits             | 70    || Rpl_semi_sync_master_no_times              | 0     || Rpl_semi_sync_master_no_tx                 | 0     || Rpl_semi_sync_master_status                | ON    || Rpl_semi_sync_master_timefunc_failures     | 0     || Rpl_semi_sync_master_tx_avg_wait_time      | 380   || Rpl_semi_sync_master_tx_wait_time          | 13305 || Rpl_semi_sync_master_tx_waits              | 35    || Rpl_semi_sync_master_wait_pos_backtraverse | 0     || Rpl_semi_sync_master_wait_sessions         | 0     || Rpl_semi_sync_master_yes_tx                | 35    |+--------------------------------------------+-------+14 rows in set (0.00 sec)

   在两台从服务器的配置

10. 从服务器上运行change master to

    MariaDB [(none)]> CHANGE MASTER TO    ->   MASTER_HOST='192.168.205.37',    ->   MASTER_USER='repluser',    ->   MASTER_PASSWORD='centos',    ->   MASTER_PORT=3306,    ->   MASTER_LOG_FILE='bin.000003',    ->   MASTER_LOG_POS=401,    ->   MASTER_CONNECT_RETRY=10;Query OK, 0 rows affected (0.02 sec)

11. 安装插件在从服务器上，没开启同步状态为OFF

    MariaDB [(none)]> install plugin rpl_semi_sync_slave soname 'semisync_slave.so';Query OK, 0 rows affected (0.00 sec)MariaDB [(none)]> show variables like '%semi%';+---------------------------------+-------+| Variable_name                   | Value |+---------------------------------+-------+| rpl_semi_sync_slave_enabled     | OFF   || rpl_semi_sync_slave_trace_level | 32    |+---------------------------------+-------+2 rows in set (0.00 sec)

12. 开启半同步，此时再查看同步变量为ON

    MariaDB [(none)]> set global rpl_semi_sync_slave_enabled=on;Query OK, 0 rows affected (0.00 sec)MariaDB [(none)]> show variables like '%semi%';             +---------------------------------+-------+| Variable_name                   | Value |+---------------------------------+-------+| rpl_semi_sync_slave_enabled     | ON    || rpl_semi_sync_slave_trace_level | 32    |+---------------------------------+-------+2 rows in set (0.00 sec)

13. 此进查看状态为OFF,我们需要开启slave线程

    MariaDB [(none)]> show global status like '%semi%';+----------------------------+-------+| Variable_name              | Value |+----------------------------+-------+| Rpl_semi_sync_slave_status | OFF   |+----------------------------+-------+1 row in set (0.00 sec)MariaDB [(none)]> stop slave;Query OK, 0 rows affected, 1 warning (0.00 sec)MariaDB [(none)]> start salve;ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'salve' at line 1MariaDB [(none)]> start slave;Query OK, 0 rows affected (0.00 sec)MariaDB [(none)]> show global status like '%semi%';+----------------------------+-------+| Variable_name              | Value |+----------------------------+-------+| Rpl_semi_sync_slave_status | ON    |+----------------------------+-------+1 row in set (0.00 sec)MariaDB [(none)]> show slave status\G;*************************** 1. row ***************************               Slave_IO_State: Waiting for master to send event                  Master_Host: 192.168.205.37                  Master_User: repluser                  Master_Port: 3306                Connect_Retry: 10              Master_Log_File: bin.000003          Read_Master_Log_Pos: 401               Relay_Log_File: mariadb-relay-bin.000002                Relay_Log_Pos: 523        Relay_Master_Log_File: bin.000003             Slave_IO_Running: Yes            Slave_SQL_Running: Yes

14. 此时我们在主服务器上查看半同步的状态

    MariaDB [(none)]> show global status like '%semi%';+--------------------------------------------+-------+| Variable_name                              | Value |+--------------------------------------------+-------+| Rpl_semi_sync_master_clients               | 2     |  #已经有两个客户端说明正常| Rpl_semi_sync_master_net_avg_wait_time     | 363   || Rpl_semi_sync_master_net_wait_time         | 25473 || Rpl_semi_sync_master_net_waits             | 70    || Rpl_semi_sync_master_no_times              | 0     || Rpl_semi_sync_master_no_tx                 | 0     || Rpl_semi_sync_master_status                | ON    || Rpl_semi_sync_master_timefunc_failures     | 0     || Rpl_semi_sync_master_tx_avg_wait_time      | 380   || Rpl_semi_sync_master_tx_wait_time          | 13305 || Rpl_semi_sync_master_tx_waits              | 35    || Rpl_semi_sync_master_wait_pos_backtraverse | 0     || Rpl_semi_sync_master_wait_sessions         | 0     || Rpl_semi_sync_master_yes_tx                | 35    |+--------------------------------------------+-------+14 rows in set (0.00 sec)

15. 测试将一个库文件导入到主服务器上，在两个从服务器上查看是否同步

    [root@master ~]#mysql < hellodb_innodb.sql MariaDB [(none)]> show databases;+--------------------+| Database           |+--------------------+| information_schema || hellodb            || mysql              || performance_schema || test               |+--------------------+5 rows in set (0.00 sec)两台从服务器上查看库MariaDB [(none)]>   show databases;+--------------------+| Database           |+--------------------+| information_schema || hellodb            || mysql              || performance_schema || test               |+--------------------+5 rows in set (0.00 sec)

    准备CA和证书

16. 为了简化我们在主服务器上产生一个自签名的根证书，首先产生一个私钥

    [root@master ~]#mkdir /etc/my.cnf.d/ssl[root@master ~]#cd /etc/my.cnf.d/ssl[root@master ssl]#openssl genrsa 2048 > cakey.pem

17. 利用私钥产生自签名的根证书

    [root@master ssl]#openssl req -new -x509 -key cakey.pem -out cacert.pem -days 3650

18. 为简化我们先产生一个私钥，并使用这个私钥为master生成证书请求文件，注意这时不是证书，是证书请求文件

    [root@master ssl]#openssl req -newkey rsa:1024 -days 365 -nodes -keyout master.key > master.csrGenerating a 1024 bit RSA private key.............++++++...++++++writing new private key to 'master.key'-----You are about to be asked to enter information that will be incorporatedinto your certificate request.What you are about to enter is what is called a Distinguished Name or a DN.There are quite a few fields but you can leave some blankFor some fields there will be a default value,If you enter '.', the field will be left blank.-----Country Name (2 letter code) [XX]:CNState or Province Name (full name) []:beijingLocality Name (eg, city) [Default City]:beijingOrganization Name (eg, company) [Default Company Ltd]:contoso    Organizational Unit Name (eg, section) []:devopsCommon Name (eg, your name or your server's hostname) []:master.contoso.comEmail Address []:Please enter the following 'extra' attributesto be sent with your certificate requestA challenge password []:An optional company name []:[root@centos7 ssl]#lscacert.pem  cakey.pem  master.csr  master.key

19. 根据请求文件生成证书文件

    [root@master ssl]#openssl x509 -req -in master.csr -CA cacert.pem -CAkey cakey.pem -set_serial 01 > master.crt Signature oksubject=/C=CN/ST=beijing/L=beijing/O=contoso/OU=devops/CN=master.contoso.comGetting CA Private Key[root@master ssl]#lltotal 20-rw-r--r-- 1 root root 1334 Aug 11 21:55 cacert.pem-rw-r--r-- 1 root root 1675 Aug 11 21:52 cakey.pem-rw-r--r-- 1 root root 1034 Aug 11 23:01 master.crt-rw-r--r-- 1 root root  664 Aug 11 21:59 master.csr-rw-r--r-- 1 root root  916 Aug 11 21:59 master.key

20. 重复18和19再生成两个从节点证书文件

    [root@master ssl]#openssl req -newkey rsa:1024 -days 365 -nodes -keyout slave1.key > slave1.csr       Generating a 1024 bit RSA private key.....++++++........++++++writing new private key to 'slave1.key'-----You are about to be asked to enter information that will be incorporatedinto your certificate request.What you are about to enter is what is called a Distinguished Name or a DN.There are quite a few fields but you can leave some blankFor some fields there will be a default value,If you enter '.', the field will be left blank.-----Country Name (2 letter code) [XX]:CNState or Province Name (full name) []:beijingLocality Name (eg, city) [Default City]:beijingOrganization Name (eg, company) [Default Company Ltd]:contosoOrganizational Unit Name (eg, section) []:devopsCommon Name (eg, your name or your server's hostname) []:slave1.contoso.comEmail Address []:Please enter the following 'extra' attributesto be sent with your certificate requestA challenge password []:An optional company name []:[root@master ssl]#openssl req -newkey rsa:1024 -days 365 -nodes -keyout slave2.key > slave2.csr Generating a 1024 bit RSA private key.++++++........++++++writing new private key to 'slave2.key'-----You are about to be asked to enter information that will be incorporatedinto your certificate request.What you are about to enter is what is called a Distinguished Name or a DN.There are quite a few fields but you can leave some blankFor some fields there will be a default value,If you enter '.', the field will be left blank.-----Country Name (2 letter code) [XX]:CNState or Province Name (full name) []:beijingLocality Name (eg, city) [Default City]:beijingOrganization Name (eg, company) [Default Company Ltd]:contosoOrganizational Unit Name (eg, section) []:devopsCommon Name (eg, your name or your server's hostname) []:slave2.contoso.comEmail Address []:Please enter the following 'extra' attributesto be sent with your certificate requestA challenge password []:An optional company name []:[root@master ssl]#openssl x509 -req -in slave1.csr -CA cacert.pem -CAkey cakey.pem -set_serial 02 > slave1.crt Signature oksubject=/C=CN/ST=beijing/L=beijing/O=contoso/OU=devops/CN=slave1.contoso.comGetting CA Private Key[root@master ssl]#openssl x509 -req -in slave2.csr -CA cacert.pem -CAkey cakey.pem -set_serial 03 > slave2.crt Signature oksubject=/C=CN/ST=beijing/L=beijing/O=contoso/OU=devops/CN=slave2.contoso.comGetting CA Private Key

21. 最终生成如下的文件

    [root@master ssl]#lltotal 44-rw-r--r-- 1 root root 1334 Aug 11 21:55 cacert.pem-rw-r--r-- 1 root root 1675 Aug 11 21:52 cakey.pem-rw-r--r-- 1 root root 1034 Aug 11 23:01 master.crt-rw-r--r-- 1 root root  664 Aug 11 21:59 master.csr-rw-r--r-- 1 root root  916 Aug 11 21:59 master.key-rw-r--r-- 1 root root 1034 Aug 11 23:05 slave1.crt-rw-r--r-- 1 root root  664 Aug 11 23:04 slave1.csr-rw-r--r-- 1 root root  916 Aug 11 23:04 slave1.key-rw-r--r-- 1 root root 1034 Aug 11 23:06 slave2.crt-rw-r--r-- 1 root root  664 Aug 11 23:05 slave2.csr-rw-r--r-- 1 root root  916 Aug 11 23:05 slave2.key

22. 将文件复制到从节点上, 正常我们只需要根证书和自己的私钥和证书三个文件即可

    [root@master ssl]#scp -r /etc/my.cnf.d/ssl/ 192.168.205.47:/etc/my.cnf.d/[root@master ssl]#scp -r /etc/my.cnf.d/ssl/ 192.168.205.57:/etc/my.cnf.d/

    配置证书在主节点

23. 查看加密的相关变量都是空

    MariaDB [(none)]> show variables like '%ssl%';+---------------+----------+| Variable_name | Value    |+---------------+----------+| have_openssl  | DISABLED || have_ssl      | DISABLED || ssl_ca        |          || ssl_capath    |          || ssl_cert      |          || ssl_cipher    |          || ssl_key       |          |+---------------+----------+7 rows in set (0.00 sec)

24. 修改配置文件

    [root@master ssl]#vi /etc/my.cnf[mysqld]ssl-ca=/etc/my.cnf.d/ssl/cacert.pemssl-cert=/etc/my.cnf.d/ssl/master.crtssl-key=/etc/my.cnf.d/ssl/master.key [root@master ssl]#systemctl restart mariadb

25. 此时查看变量值，但因为你连接时没有起用加密，所以状态的ssl为not in use

    MariaDB [(none)]> show variables like '%ssl%';+---------------+------------------------------+| Variable_name | Value                        |+---------------+------------------------------+| have_openssl  | YES                          || have_ssl      | YES                          || ssl_ca        | /etc/my.cnf.d/ssl/cacert.pem || ssl_capath    |                              || ssl_cert      | /etc/my.cnf.d/ssl/master.crt || ssl_cipher    |                              || ssl_key       | /etc/my.cnf.d/ssl/master.key |+---------------+------------------------------+7 rows in set (0.00 sec)MariaDB [(none)]> status--------------mysql  Ver 15.1 Distrib 5.5.60-MariaDB, for Linux (x86_64) using readline 5.1Connection id:          6Current database:Current user:           root@localhostSSL:                    Not in use…

26. 使用客户端加密的方式连接，可以看到状态为加密的

    [root@master ssl]#mysql --ssl-ca=cacert.pem --ssl-cert=master.crt --ssl-key=master.key MariaDB [(none)]> status--------------mysql  Ver 15.1 Distrib 5.5.60-MariaDB, for Linux (x86_64) using readline 5.1Connection id:          5Current database:Current user:           root@localhostSSL:                    Cipher in use is DHE-RSA-AES256-GCM-SHA384…

27. 我们再从节点上测试用ssl连接主节点

    [root@slave1 ssl]#mysql --ssl-ca=cacert.pem --ssl-cert=slave1.crt --ssl-key=slave1.key -h292.168.205.37 -urepluser -pcentosMariaDB [(none)]> status--------------mysql  Ver 15.1 Distrib 5.5.60-MariaDB, for Linux (x86_64) using readline 5.1Connection id:          8Current database:Current user:           repluser@192.168.205.47SSL:                    Cipher in use is DHE-RSA-AES256-GCM-SHA384

28. 但我们也可以不用加密去连接，所以我们可以建立一个用强制使用加密方的连接数据库

    MariaDB [(none)]> grant replication slave on *.* to  repluser2@'192.168.205.%' identified by 'centos' require ssl;Query OK, 0 rows affected (0.00 sec)

29. 用建立的帐号从另外一台从服务器尝试去登录

    [root@slave1 ssl]#mysql  -h292.168.205.37 -urepluser2 -pcentos                                                                 ERROR 1045 (28000): Access denied for user 'repluser2'@'192.168.205.47' (using password: YES)[root@slave1 ssl]#mysql --ssl-ca=cacert.pem --ssl-cert=slave1.crt --ssl-key=slave1.key -h292.168.205.37 -urepluser2 -pcentosWelcome to the MariaDB monitor.  Commands end with ; or \g.Your MariaDB connection id is 14Server version: 5.5.60-MariaDB MariaDB ServerCopyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.MariaDB [(none)]> status--------------mysql  Ver 15.1 Distrib 5.5.60-MariaDB, for Linux (x86_64) using readline 5.1Connection id:          14Current database:Current user:           repluser2@192.168.205.47SSL:                    Cipher in use is DHE-RSA-AES256-GCM-SHA384

    配置证书在从节点

30. 所以如果使用repluser2去和主服务器建立复制，我们需要修改配置文件

    [root@slave1 ssl]#vi /etc/my.cnf[mysqld]ssl-ca=/etc/my.cnf.d/ssl/cacert.pemssl-cert=/etc/my.cnf.d/ssl/slave1.crtssl-key=/etc/my.cnf.d/ssl/slave1.key   [root@slave1 ssl]#systemctl restart mariadb[root@slave2 ssl]#vi /etc/my.cnf[mysqld]ssl-ca=/etc/my.cnf.d/ssl/cacert.pemssl-cert=/etc/my.cnf.d/ssl/slave2.crtssl-key=/etc/my.cnf.d/ssl/salve2.key [root@slave1 ssl]#systemctl restart mariadb

31. 在从节点上停掉当前使用的repluser复制，重新使用repluser2进行复制(复制前要确定主服务器的位置)

    MariaDB [(none)]> stop slave;Query OK, 0 rows affected (0.00 sec)MariaDB [(none)]> reset slave all;Query OK, 0 rows affected (0.00 sec)MariaDB [(none)]> CHANGE MASTER TO    ->   MASTER_HOST='192.168.205.37',    ->   MASTER_USER='repluser2',    ->   MASTER_PASSWORD='centos',    ->   MASTER_PORT=3306,    ->   MASTER_LOG_FILE='bin.000004',    ->   MASTER_LOG_POS=496,    ->   MASTER_SSL=1;Query OK, 0 rows affected (0.01 sec)

32. 启动slave查看状态，一连接和复制正常

    MariaDB [(none)]> start slave;Query OK, 0 rows affected (0.00 sec)MariaDB [(none)]> show slave status\G;*************************** 1. row ***************************               Slave_IO_State: Waiting for master to send event                  Master_Host: 192.168.205.37                  Master_User: repluser2                  Master_Port: 3306                Connect_Retry: 10              Master_Log_File: bin.000004          Read_Master_Log_Pos: 415               Relay_Log_File: mariadb-relay-bin.000003                Relay_Log_Pos: 693        Relay_Master_Log_File: bin.000004             Slave_IO_Running: Yes            Slave_SQL_Running: Yes        …           Master_SSL_Allowed: Yes        …

    测试

33. 删除以前不用的复制帐号，建表或删库测试，

    MariaDB [(none)]> drop user repluser@'192.168.205.%';Query OK, 0 rows affected (0.00 sec)MariaDB [(none)]> select user,host,password from mysql.user;+-----------+---------------------+-------------------------------------------+| user      | host                | password                                  |+-----------+---------------------+-------------------------------------------+| root      | localhost           |                                           || root      | centos7.localdomain |                                           || root      | 127.0.0.1           |                                           || root      | ::1                 |                                           ||           | localhost           |                                           ||           | centos7.localdomain |                                           || repluser2 | 192.168.205.%       | *128977E278358FF80A246B5046F51043A2B1FCED |+-----------+---------------------+-------------------------------------------+7 rows in set (0.00 sec)MariaDB [(none)]> create database db1    -> ;Query OK, 1 row affected (0.01 sec)MariaDB [(none)]> MariaDB [(none)]> MariaDB [(none)]> MariaDB [(none)]> show databases;+--------------------+| Database           |+--------------------+| information_schema || db1                || hellodb            || mysql              || performance_schema || test               |+--------------------+6 rows in set (0.00 sec)

34. 在从节点上测试库是否建立, 发现出错，原因是从服务器在帐号repluser建立后复制的，所以当我们删除时因为从服务器上没有，所以出错误了，解决办法是跳过这次错误， 再次测试，发现db1复制成功，在slave2做同样的测试。

    MariaDB [(none)]> show slave status\G*************************** 1. row ***************************               Slave_IO_State: Waiting for master to send event                  Master_Host: 192.168.205.37                  Master_User: repluser2                  Master_Port: 3306                Connect_Retry: 60              Master_Log_File: bin.000004          Read_Master_Log_Pos: 749               Relay_Log_File: mariadb-relay-bin.000002                Relay_Log_Pos: 602        Relay_Master_Log_File: bin.000004             Slave_IO_Running: Yes            Slave_SQL_Running: No              Replicate_Do_DB:           Replicate_Ignore_DB:            Replicate_Do_Table:        Replicate_Ignore_Table:       Replicate_Wild_Do_Table:   Replicate_Wild_Ignore_Table:                    Last_Errno: 1396                   Last_Error: Error 'Operation DROP USER failed for 'repluser'@'192.168.205.%'' on query. Default database: ''. Query: 'drop user repluser@'192.168.205.%''    ….#注意此跳包括正确和错误的计数，如果正确的被跳过可能出现错误复制。MariaDB [(none)]> set global sql_slave_skip_counter = 1; Query OK, 0 rows affected (0.00 sec)MariaDB [(none)]> stop slave;Query OK, 0 rows affected (0.00 sec)MariaDB [(none)]> start slave;Query OK, 0 rows affected (0.00 sec)MariaDB [(none)]> show slave status\G*************************** 1. row ***************************               Slave_IO_State: Waiting for master to send event                  Master_Host: 192.168.205.37                  Master_User: repluser2                  Master_Port: 3306                Connect_Retry: 60              Master_Log_File: bin.000004          Read_Master_Log_Pos: 749               Relay_Log_File: mariadb-relay-bin.000003                Relay_Log_Pos: 523        Relay_Master_Log_File: bin.000004             Slave_IO_Running: Yes            Slave_SQL_Running: Yes        ….MariaDB [(none)]> show databases;+--------------------+| Database           |+--------------------+| information_schema || db1                || hellodb            || mysql              || performance_schema || test               |+--------------------+6 rows in set (0.00 sec)