mysql replication steps

7/31/2019 MYSQL Replication Steps

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MYSQL Replication StepsFor Linux (Redhat)

7/6/2012

HCL Infosystems

Ashish Shinde


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MySQL Master-MTo set up a dual master replication with MySQL, only some '

a basic setup and I've tried to gather common commands to

The first step is to configure both mysql using the file my.c

on matisse (192.168.14.13), under the mysqld section we ad

server-id=1

master-host=192.168.14.3

master-user=repl

master-password=repl

master-port=3306

log-bin

binlog-do-db=replication

replicate-do-db=replication

auto_increment_increment = 10

auto_increment_offset = 1

aster Replicationmodification must be done, it's very simple and there is a lot of howto'

' maintain such solution.

f (usualy on /etc in GNU/Linux) :

d the following :

Author: Ashish Shinde

HCL Infosystems

' on the topic. This is my contribution with


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and on picasso (192.168.14.3), under the same section :

server-id=2

master-host=192.168.14.13

master-user=repl

master-password=repl

master-port=3306

log-bin

binlog-do-db=replication

replicate-do-db=replication

auto_increment_increment = 10

auto_increment_offset = 2

explanations of these settings :

server-id : this is an integer id helping to identify the server (must be unique in your replication farm!) master-host : specifies the ip/hostname of the MySQL acting as master for the current server master-user : specifies the user used to make the connection to the master master-password : is the user's password master-port : specifies on which port the master is listening log-bin : needed to start the binary logging process binlog-do-db : specifies on which databases the binary logging must be active (only those databases will be in the binary log) replicate-do-db : which database must be replicated by the server as slave. auto_increment_increment : controls the increment between successive AUTO_INCREMENT values. auto_increment_offset : determines the starting point for AUTO_INCREMENT column values.The last two options are needed to prevent key collisions when using AUTO_INCREMENT columns, otherwise multiple masters may attempt to use the same

AUTO_INCREMENT value when inserting rows.

optionally two extra options can be added :

show-slave-auth-info : Display slave usernames and passwords in the output of SHOW SLAVE HOSTS on the master server. slave_compressed_protocol={0|1} : this option enable the use of compression for the slave/master protocol if both the slave and the master support it. The default is 0

(no compression). This accelerates the replication process

Creating the replication user on both nodes :

on miro :

mysql> grant replication slave, replication client on *.* to repl@"matisse" identified by "repl";

Query OK, 0 rows affected (0.00 sec)

mysql> show grants for repl@"matisse";

+--+| Grants for repl@matisse|+--+| GRANT REPLICATION SLAVE, REPLICATION CLIENT ON *.* TO 'repl'@'matisse' IDENTIFIED BY PASSWORD '5ec3db8f603fcb03'|+--+1 row in set (0.00 sec)

on matisse :

mysql> grant replication slave, replication client on *.* to repl@"miro" identified by "repl";


mysql> show grants for repl@"miro";

+---+| Grants for repl@miro |+---+| GRANT REPLICATION SLAVE, REPLICATION CLIENT ON *.* TO 'repl'@'miro' IDENTIFIED BY PASSWORD '5ec3db8f603fcb03' |+---+1 row in set (0.00 sec)


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Create the database (in this example the db is not existing) :

on the master (matisse)

mysql> create database replication;

Query OK, 1 row affected (0.05 sec)

mysql> show master status;

++++--+

| File | Position | Binlog_Do_DB | Binlog_Ignore_DB |++++--+| matisse-bin.000004 | 98 | replication | |++++--+1 row in set (0.00 sec)

mysql> show slave status\G

*************************** 1. row ***************************

Slave_IO_State: Connecting to master

Master_Host: 10.0.0.2

Master_User: repl

Master_Port: 3306

Connect_Retry: 16

Master_Log_File: localhost-bin.000001

Read_Master_Log_Pos: 310

Relay_Log_File: matisse-relay-bin.000006

Relay_Log_Pos: 98

Relay_Master_Log_File: localhost-bin.000001

Slave_IO_Running: No

Slave_SQL_Running: Yes

Replicate_Do_DB: replication

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: 310

Relay_Log_Space: 98

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

1 row in set (0.00 sec)


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on the slave :


+++++

| File | Position | Binlog_Do_DB | Binlog_Ignore_DB |

+++++

| localhost-bin.000001 | 98 | replication | |

+++++


mysql> show master status\G

*************************** 1. row ***************************

File: localhost-bin.000001

Position: 98Binlog_Do_DB: replication

Binlog_Ignore_DB:



*************************** 1. row ***************************

Slave_IO_State: Waiting for master to send event

Master_Host: 192.168.14.13

Master_User: repl

Master_Port: 3306

Connect_Retry: 60

Master_Log_File: matisse-bin.000004


Relay_Log_File: localhost-relay-bin.000006

Relay_Log_Pos: 237

Relay_Master_Log_File: matisse-bin.000004

Slave_IO_Running: Yes




Replicate_Do_Table:




Last_Errno: 0

Last_Error:

Skip_Counter: 0

Exec_Master_Log_Pos: 98Relay_Log_Space: 237


Until_Log_File:

Until_Log_Pos: 0


Master_SSL_CA_File:

Master_SSL_CA_Path:

Master_SSL_Cert:

Master_SSL_Cipher:

Master_SSL_Key:

Seconds_Behind_Master: 0


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Then, we create a table on the master (matisse) :

mysql> create table users (

-> id int(4) auto_increment not null primary key,

-> name varchar(15));


on the slave (miro) :

mysql> use replication;

Database changed

mysql> show tables;

+---+| Tables_in_replication |+---+| users |+---+1 row in set (0.00 sec)

we can also check this in the status :

on the master :


++++--+| File | Position | Binlog_Do_DB | Binlog_Ignore_DB |++++--+| matisse-bin.000004 | 258 | replication | |++++--+1 row in set (0.00 sec)

and on the slave :


*************************** 1. row ***************************


Master_Host: 192.168.14.13

Master_User: repl

Master_Port: 3306

Connect_Retry: 60

Master_Log_File: matisse-bin.000004

Read_Master_Log_Pos: 258Relay_Log_File: localhost-relay-bin.000006Relay_Log_Pos: 397

Relay_Master_Log_File: matisse-bin.000004Slave_IO_Running: YesSlave_SQL_Running: YesReplicate_Do_DB: replication

Replicate_Ignore_DB:Replicate_Do_Table:

Replicate_Ignore_Table:Replicate_Wild_Do_Table:

Replicate_Wild_Ignore_Table:Last_Errno: 0Last_Error:

Skip_Counter: 0Exec_Master_Log_Pos: 258

Relay_Log_Space: 397Until_Condition: NoneUntil_Log_File:Until_Log_Pos: 0

Master_SSL_Allowed: NoMaster_SSL_CA_File:Master_SSL_CA_Path:

Master_SSL_Cert:Master_SSL_Cipher:

Master_SSL_Key:Seconds_Behind_Master: 0



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And now we can create records. The first scenario is the following :

1) add 2 records on the master

2) add 2 records on the s lave

on the master :

mysql> insert into users values (0,"fred"),(0,"vanne");

Query OK, 2 rows affected (0.00 sec)Records: 2 Duplicates: 0 Warnings: 0

on the slave :

mysql> select * from users;

++---+| id | name |++---+| 1 | fred || 11 | vanne |++---+2 rows in set (0.00 sec)

mysql> insert into users values (0,"raskas"),(0,"stintel");


Records: 2 Duplicates: 0 Warnings: 0

on the master :


++-+| id | name |++-+| 1 | fred || 11 | vanne || 12 | raskas || 22 | stintel |++-+

Good ! Our first master-master replication is working !

Now let stop the slave and add 2 extar records on the master :

mysql> slave stop;

Query OK, 0 rows affected (0.00 sec

on the master :

mysql> insert into users values (0,"sdog"),(0,"jacke");



and on the slave :


++-+| id | name |++-+| 1 | fred || 11 | vanne || 12 | raskas || 22 | stintel |++-+4 rows in set (0.00 sec)

let's try to add some data on the slave too (the databases are not synchronized, but matisse is still slave of miro) :

on miro (the slacve):

mysql> insert into users values (0,"jozzel"),(0,"pleemans");




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++--+| id | name |++--+| 1 | fred || 11 | vanne || 12 | raskas || 22 | stintel || 32 | jozzel || 42 | pleemans |

++--+6 rows in set (0.00 sec)

on matisse (the master) :


++--+| id | name |++--+| 1 | fred || 11 | vanne || 12 | raskas || 22 | stintel || 31 | sdog || 41 | jacke || 32 | jozzel || 42 | pleemans |++--+8 rows in set (0.00 sec)

now let's start slave again on miro :

mysql> slave start;



++--+| id | name |++--+| 1 | fred || 11 | vanne || 12 | raskas || 22 | stintel || 32 | jozzel || 42 | pleemans || 31 | sdog || 41 | jacke |

++--+8 rows in set (0.00 sec)

Ok this is great an works like expected.

For our last test we gonna add some new records on both nodes but previously we gonna stop both slave process :

on matisse :

mysql> insert into users values (0,"alain"),(0,"tux");




++--+| id | name |

++--+| 1 | fred || 11 | vanne || 12 | raskas || 22 | stintel || 31 | sdog || 41 | jacke || 32 | jozzel || 42 | pleemans || 51 | alain || 61 | tux |++--+10 rows in set (0.00 sec)

on miro :

(I will even remove a record)

mysql> insert into users values (0,"billou"),(0,"Linus");




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mysql> delete from users where id=22;



++--+| id | name |++--+| 1 | fred || 11 | vanne || 12 | raskas || 32 | jozzel || 42 | pleemans || 31 | sdog || 41 | jacke || 52 | billou || 62 | Linus |++--+9 rows in set (0.00 sec)

let's restart both slaves :

from matisse :


++--+| id | name |

++--+| 1 | fred || 11 | vanne || 12 | raskas || 31 | sdog || 41 | jacke || 32 | jozzel || 42 | pleemans || 51 | alain || 61 | tux || 52 | billou || 62 | Linus |++--+11 rows in set (0.00 sec)

from miro :


++--+| id | name |++--+| 1 | fred || 11 | vanne || 12 | raskas || 51 | alain || 32 | jozzel || 42 | pleemans || 31 | sdog || 41 | jacke || 52 | billou || 62 | Linus || 61 | tux |++--+11 rows in set (0.00 sec)

and what happens if we try do delete the same record when both slaves are stopped ?

on both :

mysql> slave stop;


mysql> delete from users where id =52;


mysql> slave start;



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++--+| id | name |++--+| 1 | fred || 11 | vanne || 12 | raskas || 31 | sdog || 41 | jacke || 32 | jozzel |

| 42 | pleemans || 51 | alain || 61 | tux || 62 | Linus |++--+10 rows in set (0.00 sec)


*************************** 1. row ***************************


Master_Host: 192.168.14.3

Master_User: repl

Master_Port: 3306

Connect_Retry: 16

Master_Log_File: localhost-bin.000002Read_Master_Log_Pos: 851

Relay_Log_File: matisse-relay-bin.000009

Relay_Log_Pos: 344

Relay_Master_Log_File: localhost-bin.000002





Replicate_Do_Table:




Last_Errno: 0

Last_Error:

Skip_Counter: 0


Relay_Log_Space: 344


Until_Log_File:

Until_Log_Pos: 0


Master_SSL_CA_File:

Master_SSL_CA_Path:

Master_SSL_Cert:

Master_SSL_Cipher:

Master_SSL_Key:



cool ! no errors and everything seems to be as it should be.


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Some maintenance :

it's also nice to know some maintenance commands.

the first dba replication action will be to manage the binary logs that could increase very quickly.

to see the logs use the following command :

mysql> show master logs;

++---+| Log_name | File_size |++---+| matisse-bin.000001 | 381 || matisse-bin.000002 | 117 || matisse-bin.000003 | 219 || matisse-bin.000004 | 427 || matisse-bin.000005 | 739 |++---+5 rows in set (0.00 sec)

Then after having done a backup (long silence), you can purge then since a date (could be a day in the past or even now :

mysql> purge master logs before now();



++---+

| Log_name | File_size |++---+| matisse-bin.000005 | 739 |++---+1 row in set (0.00 sec)

or


++-+| Log_name | File_size |++-+| localhost-bin.000001 | 271 || localhost-bin.000002 | 851 |++-+2 rows in set (0.00 sec)

mysql> purge master logs to 'localhost-bin.000002';



++-+| Log_name | File_size |++-+| localhost-bin.000002 | 851 |++-+1 row in set (0.00 sec)

To reset the slave and the master you should use :

reset master;

reset slave;


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How-To: Setup Mysql Replication A simple guide

The following is a simple guide to help you setup Mysql replication a fantastic way to

ensure you have an up-to-date backup of your production databases.This guide only describes a single master-slave relationship, however you can use mysql in various modes whichinclude additional slaves as required.

Production Replication SetupThe master (production server) needs to have binary logging turned on to facilitate replication. To turn on binarylogging, we need to take the following steps:

Using phpMyAdmin, add a new user called replication_user which only has REPLICATION SLAVE access rights Add the following lines to the /etc/my.cnffile:

[mysqld]

log-bin=mysql-bin

server-id=1

Restart mysql (as root)[user@server]# service mysqld restart

Stop the production server, and obtain its state information. Most importantly, note the File and Position values:mysql> FLUSH TABLES WITH READ LOCK;

mysql> SHOW MASTER STATUS;

+---------------+----------+--------------+------------------+

| File | Position | Binlog_Do_DB | Binlog_Ignore_DB |

+---------------+----------+--------------+------------------+

| mysql-bin.003 | 240 | test | manual,mysql |

+---------------+----------+--------------+------------------+

While the database has the READ LOCK applied, export the data using mysqldump, including master datainformation:

mysqldump --all-databases --master-data > dbdump.db

Then unlock the master database:mysql> UNLOCK TABLES;

Slave Replication SetupTo initialise the slave server, the following steps need to be taken:

Add the following to the slave servers config file /etc/my.cnf:# Replication settings

log-bin

replicate-ignore-db=mysql

relay-log=triton-relay-bin

log-slave-updates

log-warnings

server-id=2

# Slave details

report-host=slave.mydomain.com # YOUR SLAVE'S HOSTNAME

# Master Host details


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master-host=master.mydomain.com # YOUR MASTER'S HOSTNAME

master-user=replication_user

master-password=mypasswordhere # YOUR REPLICATION USERS PASSWORD

master-port=3306

Transfer the data (dbdump.db) file from Master and load it into the database:shell> mysql < fulldb.dump

Set the file information this needs to match the values you observed on the master when you locked the tablesabove. In this example the filename was mysql-bin.003and the log position was 240:

mysql> change master to

MASTER_LOG_FILE='mysql-bin.003',

MASTER_LOG_POS=240;

Start the slave:mysql> start slave;

You should now have a working mysql replication database! Login to phpMyAdmin or something similar on the slaveto confirm that all the databases are there.

Checking Replication is WorkingIts important to check that replication is working once you set it up. Some information can be gathered from themysql log (usually found in /var/log/mysqld.log), however the following steps are more conslusive:

On the production server, issue the following command to see which slaves are connected:mysql> show slave hosts;

+-----------+------------------------------+------+-------------------+-----------+

| Server_id | Host | Port | Rpl_recovery_rank | Master_id |

+-----------+------------------------------+------+-------------------+-----------+

| 2 | slave.mydomain.com | 3306 | 0 | 1 |

+-----------+------------------------------+------+-------------------+-----------+


On the backup server, issue the following command to see the slave status:mysql> show slave status\G

*************************** 1. row ***************************


Master_Host: master.mydomain.com

Master_User: replication_user

Master_Port: 3306

Connect_Retry: 60

Master_Log_File: mysql-bin.000001


Relay_Log_File: slave-relay-bin.000004

Relay_Log_Pos: 250751844

Relay_Master_Log_File: mysql-bin.000001



Replicate_Do_DB:

Replicate_Ignore_DB: mysql

Replicate_Do_Table:



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Last_Errno: 0

Last_Error:

Skip_Counter: 0


Relay_Log_Space: 250751844


Until_Log_File:

Until_Log_Pos: 0


Master_SSL_CA_File:

Master_SSL_CA_Path:

Master_SSL_Cert:

Master_SSL_Cipher:

Master_SSL_Key:


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