Detailed explanation based on CentOS 6.2 DNS master-slave replication build and deploy

1 Master-Slave dns--prepare--dns master-Slave theory

1, what is DNS?

Simple understanding, Domain Name System, is the Internet a core service, he as a bridge can be a domain name and IP address of the mutual factors of a distributed database, can make people more convenient access to the Internet, rather than to remember the complex IP address.

2, the type of DNS, Master/slave architecture;

Master This type of DNS in this configuration file, including the host name of all the host and other related information, usually we manually add modified, set up after we want to restart the service to read the contents of the master library data; Generally we do DNS when we are specifying the type of database , but also to ensure that the content of the data provided to the slave server, this requires us to set up. In the configuration file.

Slave This type of data must have master in order to use it. In general, it's a master, a master, a slvae, if we all have master then we need to add changes to two of the time to add, modify, if not careful to modify the error, very embarrassing, If we make master/slave then we can modify master directly. But here we are involved in a priority problem, whether it's master or slave, to ensure that the data is exactly the same.

3, the Master/slave data synchronization process;

First slave data is read from master, but how to notify slave after master data update? There are two ways to tell the slave database. One is master's initiative to tell slave when master modifies the content of the data and enlarges the serial number of the database and then restarts the service. The second is Slvae initiative to find master, when found that master's data and their own time, slave will update.

2) Master-slave dns--Preparation--simulated environment

1, testing environment;

Unified CentOS 6.2 X86 system, IP address planning,

Master server:192.168.6.249

Slave server:192.168.6.248

3 implementation of the master-slave DNS---deployment;

1, first we build the main master server. Use yum-y install bind Bind-chroot

2, the environment we use in this project is 6. The environment of the X-System, in 6. X-Series environment and 5.X series environment configuration is different, their biggest difference is automatic synchronization, after centos6.x with automatic synchronization function, all we configure only need to configure/etc/related configuration files, but we are now most of the enterprise environment is 5. X-Series environment, in this environment we are using to copy the relevant configuration files to the Chroot directory to do the relevant configuration, about 5. X series DNS configuration deployment, please check my previous blog post; http://devliangel.blog.51cto.com/469347/715184

3, modify the main configuration file; vim/etc/named.conf tips in general, when you modify the configuration file, please do the configuration backup, so that we modify the error after we have the correct backup is generally not afraid of. In the configuration file we modify 11 lines, change the 127.0.0.1 to any, comment out 12 lines, because we do not have IPV6, modify 17 lines, the 127.0.0.1 of the machine into any. Detailed diagram: