WebSphere Extended Deployment, Version 6.0.x
             Operating Systems: AIX, HP-UX, Linux, Solaris, Windows, z/OS


Determining the stacking number for a dynamic cluster

You can use profiling to determine the stacking number for your dynamic cluster. The stacking number is the number of cluster instances that are needed to use all the power of a node.

Before you begin

About this task

The Allow more than one instance to start on the same node enables vertical stacking on the node. When you select this option, you must provide the number of instances to start on the same node. This value is the stacking number.

You can determine the stacking number by profiling of your application. If your dynamic cluster is homogeneous, and all of the nodes for the node group have similar power, you need to profile and determine the stacking number on one node only. If your dynamic cluster is deployed to a node group with nodes that are heterogeneous and vary in power, you must profile each node and determine the stacking number for each node.

Procedure

  1. Start two instances of the same application on the same node. You can start two instances of the application on the node by creating another cluster member on the node.
  2. View the charts to see if the throughput curve starts going up. Continue increasing the number of application instances until the processor use reaches 100%. To view the charts, click Runtime operations > Runtime topology.
  3. Check the number of application instances that are active when the processor reaches 100% utilization; this number is the stacking number. Remember this number so that you can configure the stacking number in the administrative console.
  4. If your dynamic cluster is deployed on a node group that has heterogeneous nodes, repeat these steps for each node and record a stacking number for each node.

What to do next

Enable vertical stacking for your cluster.



Related concepts
Dynamic clusters
Related tasks
Configuring vertical stacking
Task topic    

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Last updated: Nov 30, 2007 3:58:31 PM EST
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