After enabling Boost mode, the virtual machine and Access service run in the same memory address space. A vHost high availability service also starts synchronously on the node to ensure operational stability. When exceptions occur with various roles in the I/O path, the impact on the virtual machine is as follows:
vHost high availability service anomaly
The vHost high availability service does not handle virtual machine I/O under normal conditions, so the virtual machine remains unaffected.
Access node anomaly
The Access node connected to a virtual machine is typically the node where the virtual machine resides. If the node experiences an overall anomaly, the virtual machine will trigger HA to rebuild on another node after a certain period. If only the Access service on the node is abnormal, the vHost high availability service will take over the virtual machine's I/O requests, redirecting them through the network to other available Access nodes in the cluster. After the Access of the node where the virtual machine is located has been restored to normal and maintained stability for a period of time, the I/O is then switched back to the Access for processing.
ChunkServer anomaly
Meta rapidly executes shard eviction and removes faulty ChunkServers when necessary to ensure I/O continuity while initiating recovery tasks to repair data.
Meta node anomaly
The ZooKeeper cluster automatically elects a new Meta leader node to quickly restore metadata services.
