Learn how to verify the Cisco APIC cluster status using the cluster_health command introduced in Cisco Application Policy Infrastructure Controller (APIC) release 4.2(1), ensuring all nodes are active and properly synchronized for optimal performance.
Cisco Application Policy Infrastructure Controller ( APIC ) release 4.2.(1) introduces the cluster_health command, which enables you to verify the Cisco APIC cluster status step-by-step. The following output example demonstrates a scenario where everything is fine except for one node (ID 1002), which is inactive.
To use the cluster_health command, you must be logged in as admin.
Procedure
Example:
F1-APIC1#
cluster_health
Password:
Running...
Checking Wiring and UUID: OK
Checking AD Processes: Running
Checking All Apics in Commission State: OK
Checking All Apics in Active State: OK
Checking Fabric Nodes: Inactive switches: ID=1002(IP=10.1.176.66/32)
Checking Apic Fully-Fit: OK
Checking Shard Convergence: OK
Checking Leadership Degration: Optimal leader for all shards
Ping OOB IPs:
APIC-1: 172.31.184.12 - OK
APIC-2: 172.31.184.13 - OK
APIC-3: 172.31.184.14 - OK
Ping Infra IPs:
APIC-1: 10.1.0.1 - OK
APIC-2: 10.1.0.2 - OK
APIC-3: 10.1.0.3 - OK
Checking APIC Versions: Same (4.2(0.261a))
Checking SSL: OK
Done!
|
Step |
Description |
|---|---|
|
Checking Wiring and UUID |
Leaf switches provide infra connectivity between each Cisco APIC by detecting the Cisco APIC s using LLDP. This step checks wiring issues between a leaf and a Cisco APIC that is detected during LLDP discovery. Any issues in here implies a leaf switch cannot provide infra connectivity for a Cisco APIC as it doesn’t have a valid information. For example, a Cisco APIC UUID mismatch means the new APIC2 has a different UUID than the previously known APIC2. UUID – Universally Unique ID, or chassis ID in some outputs |
|
Checking AD Processes |
Cisco APIC clustering is handled by the Appliance Director process on each Cisco APIC . This step checks if the process is running correctly. |
|
Checking All APIC s in Commission State |
To complete the Cisco APIC clustering, all Cisco APIC s need to be commissioned. |
|
Checking All APIC s in Active State |
To complete the Cisco APIC clustering, all commissioned Cisco APIC s need to be active. If it is not active, the Cisco APIC may not be up yet. |
|
Checking Fabric Nodes: Inactive switches |
The Cisco APIC 's communication are through infra connectivity provided by leaf and spine switches. This step checks inactive switches to ensure switches are providing infra connectivity. |
|
Checking APIC Fully-Fit |
When Cisco APIC s have established IP reachability to each other through infra network, it will synchronize its database to each other. When the synchronization completes, the status of all Cisco APIC s become "Fully-Fit." Otherwise, the status will be "Data Layer Partially Diverged," and so on. |
|
Checking Shard Convergence |
When Cisco APIC s are not fully-fit, database shards need to be checked to see which service is not fully synchronized. If there is any service that has problems in synchronization, you may reach out to Cisco TAC for further troubleshooting. |
|
Checking Leadership Degration |
In ACI, each database shard has one leader shard distributed to each Cisco APIC in the cluster. This step shows if all shards have an optimal leader. If there is an issue in here when all Cisco APIC s are up, you may reach out to Cisco TAC for further troubleshooting. |
|
Ping OOB IPs |
This step is to check if all Cisco APIC s are up and operational by pinging the OOB IP which is configured separately from clustering. |
|
Ping Infra IPs |
This step is to check if there is infra connectivity between each Cisco APIC . Cisco APIC clustering is performed through infra connectivity instead of OOB. |
|
Checking APIC Versions |
All Cisco APIC s should be on a same version to complete clustering. |
|
Checking SSL |
All Cisco APIC s need to have a valid SSL that should be built-in when a Cisco APIC is shopped as an appliance. Without a valid SSL, the server cannot operate the Cisco APIC OS correctly. |