The question describes a scenario where the controller and client have a significant difference in their reported latency for the same datastores.
The controller’s latency is 1 ms, which is within the normal range for ONTAP-based datastores1.
The client’s latency is 15 ms, which is much higher than the controller’s latency and could indicate a performance issue on the client side2.
Therefore, the next step is to investigate the client that reports high latency and identify the possible causes, such as network congestion, misconfiguration, resource contention, or application issues23.
The other options are not relevant or appropriate for this scenario, because:
A. The cluster is not responding slowly, as the controller’s latency is low and QoS output confirms the same.
C. The cluster interconnects are not likely to be the cause of the latency difference, as they are used for communication between nodes within the cluster, not between the controller and the client4.
D. A sync core is a diagnostic tool that captures the state of the system at a given point in time, and is not a troubleshooting step for performance issues5. References:
ONTAP 9 Performance - Resolution Guide - NetApp Knowledge Base
Performance troubleshooting - NetApp
How to troubleshoot performance issues in Data ONTAP 8 7-mode
Cluster interconnect network - NetApp
How to generate a sync core on a node - NetApp
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