It
becomes tricky to create a valid snapshot especially if your database
server is running a mission critical application and cannot be shutdown
or can sustain a read lock for long durations. In this scenario, you
can use the --single-transaction option in mysqldump
mysqldump --all-databases --master-data --single-transaction > dbdump.db
Steps involved in setting up MySQL replication
1. Create a User for Replication
Logon to the master instance
mysql -p -u root -h <IP address of master server>
Create a user with proper privileges on the master
mysql> grant REPLICATION SLAVE on *.* to repluser@<IP Address of Slave> identified by '<password>';
mysql> flush privileges;
2. Setting the Replication Master Configuration
vi /etc/my.cnf
Under section [mysqld] add the following lines
log-bin=mysql-bin
server-id=1
4. Setting the Replication Slave Configuration
vi /etc/my.cnf
Under section [mysqld] add the following lines
log-bin=mysql-bin
server-id=2
Note that this is a different ID from that of the master
5. Creating a Data Snapshot Using mysqldump
Logon to the master instance
mysql -p -u root -h <IP address of master server>
mysql> flush tables with read lock;
While this session is active open another shell and run mysqldump
mysqldump --all-databases --master-data >dbdump.db
Use of the --master-data parameter is important here.
After the dump is completed, exit from the master instance to release the read lock.
6. Setting Up Replication with New Master and Slaves
Apply the dump obtained on step 5 to the slave server
mysql -p -u root -h <IP address of slave server> < dbdump.db
Logon to the slave instance
mysql -p -u root -h <IP address of slave server>
mysql> change master to MASTER_HOST=<IP address of master server>, MASTER_USER='repluser', MASTER_PASSWORD='<password>';
Master user and the master password are from step 1.
This should start the replication on the slave server. For more details, you could refer to