Product data

Chapter 12. High availability and redundancy 303
Figure 12-3 shows both the software and hardware stack that of an SDMC High
Availability environment. These internal software components that make up
SDMC High Availability are transparent to the user and do not need to be directly
configured. IBM Tivoli System Automation for Multiplatform (TSA) is used to
monitor the hardware and software stack. It also provides failover and quorum
capability. Data is mirrored using Distributed Replicated Block Device (DRBD).
Apache MQ performs operating system synchronization, and also contains the
firewall rules, NTP configuration, network and user settings. Floating IP
addresses used to connect to the active SDMC can be moved between the
nodes with the active node. The OS on the passive node is started, but the
software stack is not.
Figure 12-3 SDMC High Availability environment before and after failover
Active Director Node
Passive Director Node
Director
Console
ThinkVisi onThinkVisi onThinkVisi on
TSA
MQ
File
System
DRBD
TSA
MQ
File
System
DRBD
Heartbeat
User/Firewall
Synchronization
Managed Systems
Active Director Node
Passive Director Node
Director
Console
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TSA
MQ
File
System
DRBD
TSA
MQ
File
System
DRBD
Heartbeat
User/Firewall
Synchronization
Managed Systems
Post-Failover