The required component is MDC.
OceanStor Pacific uses a distributed control architecture in which cluster-management and metadata/control services must remain highly available as nodes are added, removed, or experience failures. Huawei specifically identifies multi-MDC as a mechanism that improves system reliability. The training architecture also shows MDC participating in sub-health management together with storage-side processes such as OSD and EDS.
This distributed deployment is consistent with the architecture of OceanStor Pacific: storage services are spread across nodes, and control information must remain accessible regardless of the physical node role. The system therefore cannot depend on one isolated control instance.
Huawei also describes OceanStor Pacific as a three-layer scale-out architecture integrating block, file, object, and HDFS services, with cluster-status control, distributed data routing, redundancy management, rebuilding, and balancing forming core storage-engine functions. MDC supports the distributed coordination and control required by this architecture.
The supplied question set identifies MDC as the required abbreviation.
Study Guide Topics: Data Storage Technology Presentation → OceanStor Pacific → Scale-Out Architecture → MDC → Cluster Control → High Reliability.