Dell EMC VxFlex Ready Node, Руководство пользователя

Страница: 28 / 354

l
Slave MDM (used to be called Secondary MDM)
An MDM in the cluster that is ready to take over the Master MDM role if ever
necessary.
In a 3-node cluster, there is one Slave MDM, thus allowing for a single point of
failure. In a 5-node cluster, there are two Slave MDMs, thus allowing for two
points of failure. This increased resiliency is a major benefit to enabling the 5-node
cluster.
l
Replica
An MDM that contains a replica of the MDM repository. This includes the Master
MDM and any Slave MDMs in the MDM cluster.
The following table describes the available cluster modes:
Table 2 MDM cluster modes
Cluster mode Members Description
3-node (default)
l
Master MDM
l
Slave MDM
l
Tie Breaker
3-node cluster has two copies
of the repository, thus can
withstand one MDM cluster
failure.
5-node
l
Master MDM
l
Two Slave MDM
l
Two Tie Breaker
5-node cluster has three
copies of the repository, thus
can withstand two MDM
cluster failure.
Single-node
l
Master MDM
Single-node cluster has only
one copy of the repository,
thus it cannot withstand
failure. It is not recommended
to use Single Mode in
production systems.
In addition to the cluster members, you can prepare standby Managers and Tie
Breaker nodes, for a total of thirteen cluster and standby MDMs.
The MDM cluster IP address limit is 16 IP addresses, which includes all cluster
members (Master, Slave, Standby Master, and Standby Slaves).
The following figure illustrates a 5-node MDM cluster:
Figure 1 5-node MDM cluster
All members of the MDM cluster have the same MDM package installed on them.
Before a server makes its way into the MDM cluster, it must follow the following path:
1. Install the MDM package on the server.
Architecture
28 Dell EMC VxFlex Ready Node AMS User Guide