High Availability Active-Active Active-Passive Failover Domain.

Cluster High Availability It has Two Mode
1) Active-Active Mode
2) Active-Passive Mode

Active- Active Mode
1) Both Master server 1 and Master Server2 Both are Running Stages.
2) Active – Active Mode has two Failover Domain
3) It will also act the Load Balancing Mode.

ACTIVE & ACTIVE MODE – Luster File system OSS
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<failoverdomain name="OSS_Domain3" ordered="1" restricted="1">
<failoverdomainnode name="oss3" priority="1"/>
<failoverdomainnode name="oss4" priority="2"/>
</failoverdomain>
<failoverdomain name="OSS_Domain4" ordered="1" restricted="1">
<failoverdomainnode name="oss3" priority="2"/>
<failoverdomainnode name="oss4" priority="1"/>
</failoverdomain>
Active & Active OSS Node it has two failover domains,

Active Passive Mode
1) Server 1 is Active and Server 2 is standby.
So if one server 1 is down, Another Server 2 is replacing on behalf of server 1.
2) Active passive Mode has only one fail over Domain.

ACTIVE & PASSIVE MODE -Luster File system MDS
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<failoverdomain name="MDS_Domain" ordered="1" restricted="1">
<failoverdomainnode name="mds1" priority="1"/>
<failoverdomainnode name="mds2" priority="1"/>
</failoverdomain>
Active & Passive Node it has only one failover domain.

High Availability Tag Field
1)/etc/cluster/cluster.conf – Cluster Configuration File.
2)Resource Start with <resource> and </resource>
Service it is like IP Address, Storage- Mount Point, Linux Service Like http,

<ip address="20.0.1.207/16" monitor_link="1"/>

<lustrefs device="/dev/dm-0" force_fsck="0" force_unmount="0" mountpoint="/ost5" name="ost5" self_fence="1"/>

Service it will come with Name like ost5
3)Service start with <service> and </service>tag
Create New service. Add Resource using rousrce name to the service.
<lustrefs ref="ost5"/>
4) failoverdomain start and end with <failoverdomain> and
</failoverdomain>
It has node name, <failoverdomainnode name="oss3" priority="2"/>