Overview
This topic explains the process of expanding the Cisco Fabric Controller cluster to accommodate network growth, maintain redundancy, and improve performance by automatically adding controllers within approved size limits once the operator sets the desired administrative cluster size and connects the appropriate controllers.
Expanding the Cisco Fabric Controller cluster is an administrative operation that increases the cluster size to accommodate network growth, maintain redundancy, and improve performance. Cluster expansion is the administrative operation of increasing the Cisco Fabric Controller cluster size from N to N+1 within approved limits.
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Operator sets the desired administrative cluster size.
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Controllers with correct cluster IDs are connected.
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The cluster automatically performs the expansion.
Cluster Expansion Process and Considerations
Expanding clusters accommodates network growth and helps maintain redundancy and performance by including additional controllers as the needs of the organization change.
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Expansion is performed within approved cluster size boundaries.
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Operator intervention is required to set administrative size and connect controllers.
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Expansion is automatic after prerequisites are met.
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Set the administrative cluster size.
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Connect APIC controllers with appropriate cluster IDs.
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Cluster performs the expansion automatically.
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Administrative cluster size: The target size set by the operator.
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Operational cluster size: The current size after expansion completes.
During cluster expansion, discovery and expansion take place sequentially based on APIC ID numbers. For example, APIC 2 is discovered after APIC 1, APIC 3 after APIC 2, and so on until all desired APICs are added to the cluster. As each APIC is discovered, data paths are established and switches along the path join the fabric. The process continues until the operational cluster size matches the administrative cluster size.
Example: Sequential APIC Discovery During Cluster Expansion
For instance, if you add APIC 1, APIC 2, and APIC 3 to the cluster, APIC 2 is discovered after APIC 1, and APIC 3 is discovered after APIC 2. As each APIC is discovered, the cluster establishes data paths and adds switches along the path to the fabric until the desired cluster size is reached.