Types of Replication general info

Asynchronous

 Data is replicated after it has been commited. Data loss can exist
if the master server crushes before the changes are commited by the remote server.

Synchronous

System has to ensure the data written by the transaction will be present
to at least two servers when the transaction commits. Confirmation
from the remote server is needed and this creates an overhead.


 

Single Master Replication

The master server replicates the data to the slave server.
The writes go to the Master server and these changes are disturbuted
to the slaves servers.

Multi Master

In this server writes are allowed to all the servers in the cluster.
This means alot of writes can go to many nodes at the same time.


 

Logical Replication

This replication distributes the changes at a logical level. It
does not concern it self with physical layout of the data structure
of the database it self.

Physical Replication

Is the type of replication where data are moved as is. The replication
of data is done at a binary level.

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Centos6.5-Win2012R2 – Setup Windows as your Master DNS and Bind as your Slave DNS.

This tutorial show how to setup Windows 2012-R2 as a Master DNS and how to set up Centos 6 as a slave DNS.

PRIMARY DNS NAME AND IP: AD1.SFENTONA.LOL  / 10.0.0.6
SLAVE   DNS NAME AND IP: DNS1.SFENTONA.LOL /10.0.0.10

Centos DNS CONFIG STEPS

———————————————————————————————————-
The following config files have been used in order to get DNS services up and running in Centos 6.

vi /etc/resolv.conf
nameserver 127.0.0.1
search sfentona.lol
vi /etc/sysconfig/network
NETWORKING=yes
HOSTNAME=dns1.sfentona.lol
vi /etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE=eth0
HWADDR=00:0C:29:CA:90:ED
TYPE=Ethernet
UUID=49076518-17fb-4416-be14-de64aa36843a
ONBOOT=yes
NM_CONTROLLED=no
BOOTPROTO=static
IPADDR=10.0.0.10
NETMASK=255.255.255.192
GATEWAY=10.0.0.1
DNS1=127.0.0.1
DOMAIN="sfentona.lol"
vi /etc/named.conf

Under Options you will have to specify the IP address of your Centos DNS server and from which network you will accept queries.

listen-on port 53 { 127.0.0.1; 10.0.0.10; };
listen-on-v6 port 53 { ::1; };
directory "/var/named";
dump-file "/var/named/data/cache_dump.db";
statistics-file "/var/named/data/named_stats.txt";
memstatistics-file "/var/named/data/named_mem_stats.txt";
allow-query { localhost; 10.0.0.10/26; };
//allow-transfer { 10.0.0.0/26; };
recursion yes;

Under Zones you will have to create your forward lookup and reverse lookup zones. Between the sections LOGGING and ZONE include the following lines. We are essentially telling to our Centos DNS service that it is of type slave and the IP of the master DNS. We are also telling where the location of the zone files will be located

/var/named/slaves

sfentona.lol.zone

zone "sfentona.lol" IN {
type slave;
masters { 10.0.0.6; };
allow-query { any; };
file "slaves/sfentona.lol.zone";
};

sfentona.lol.rr.zone

zone "0.0.10.in-addr.arpa" IN {
type slave;
masters { 10.0.0.6; };
allow-query { any; };
file "slaves/sfentona.lol.rr.zone";
};

 

 

Windows DNS CONFIG STEPS

———————————————————————————————————-

  • On your maind DNS properties settings tree check “Enable Bind Secondaries”
  • You will have enter as Name Server your Linux Server for both your Forward and Reverse Lookup zones.
  • On your DNS Zone (in this case sfentona.lol) under properties settings enable “Zone Transfer”. Specify your slave DNS or you can opt to update all available DNS servers. Make to do this for both your Forward and Reverse lookup zones for your Domain.
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