Clustered topologies
To maximize the high availability capabilities of IBM® InfoSphere® Information Server, install it on a file system that is shared by eight or more computers in which all tiers are implemented within clusters.
In this topology, all tiers are configured with the most advanced high availability solutions, and both application server clustering and metadata repository tier clustering are implemented. The cost in hardware is high because a minimum of eight computers are required:
- Two computers for the engine tier, configured with the active-passive failover solution
- Three or more computers for the services tier, configured as an IBM WebSphere® Application Server Network Deployment cluster (the WebSphere Application Server Deployment Manager and managed nodes are deployed on dedicated computers)
- One computer for the front-end dispatcher (typically a web server) that sends requests to the IBM WebSphere Application Server Network Deployment cluster
- Two computers for the metadata repository tier that runs on IBM Db2® high availability disaster recovery (HADR) with the Automatic Client Reroute
The following diagram illustrates a topology with a clustered application server and metadata repository tier with clustered Db2.

Topology dimensions and analysis
You can adapt this topology as needed to meet available resources and specific requirements. For example, to reduce hardware cost, you can consolidate some of the tiers and components on fewer computers. You can also collocate some of the services tier cluster nodes with the Db2 HADR instances of the metadata repository tier or collocate the front-end web server with one of the Services tier nodes. Similarly, if performance and scalability at the services tier is more important than high availability, then you might consider configuring the metadata repository tier with the active-passive failover solution rather than with the Db2 HADR technology. Additionally, the engine tier and metadata repository tier can be consolidated on the same computers to mitigate the cost of two additional computers.
Consideration | Advantages and disadvantages |
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Level of high availability |
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Scalability |
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Security |
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Complexity |
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Maintainability |
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Cost | The cost is high. |