How
ClusterReplica Enterprise Works With Examples
There are two types of servers
defined in the ClusterReplica environment: the “master” and
“replica”.
While the “master” is the data
replication source, the “replica” is the data replication
destination. Some terminologies involved using ClusterReplica
Enterprise are introduced here.
- The
Primary master – this is a data replication source server that is also
the manager of the configuration of the entire clustering structure.
It defines other data replication source servers and the replication
destination servers. It is the only server that can be failed over to
a Secondary station for server-availability needs.
- The repli-master
– this is a data replication source server that needs to
replicate the data files on it to other servers in local or
remote locations. While functioning mainly as the data replication
source, a repli-master can also be used as a replica member to
receive data from other master servers. It is different from the
Primary master in the way that it does not have the management
power on the clustering.
-
The
replica–
this is a data replication destination server. It takes in data from
the master servers and manages the data in MS DPM style for easy data
distribution and recovery.
-
The
Secondary station – this is a replica station that besides
function as the data replication destination, is also defined as the
Secondary station which is ready to take over the server services of
the Primary masters should it fails at any time. There can be only one
Secondary station defined in a ClusterReplica environment. For a
smooth failover, this system is expected to have the similar system
capacity of the Primary master and with identical application
and file structure.
In
this example, there are three “master” stations: one Primary
master, two repli-master(s) and three “replica” stations. One of
the “replica” station is functioning as the Secondary station. The “replica”
stations receive and manage new data in the manner of Microsoft’s
DPM system so that when file-retrieving requests are processed, data
files can be easily found and restored. Also like the MS DPS, this
file managing and retrieving process is entirely end-user
self-service.
With
this arrangement, all server malfunctions can be avoided:
- In normal condition, the three “master” stations copy
changed data to the “replica” stations in real time.
- When the Primary master fails, the Secondary station takes up
the active server role to continue serving the network clients
- If working files on the master stations are corrupted or lost,
a previous version of the file can be retrieved from the “replica”
stations.
See Examples:
- MS SQL and IIS Web server data replication and
failover
- Real-time data replication with DPM-like
functions
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