A redundancy technology refers to a reliability mechanism in which two or more systems having similar functions are built at places relatively far from each other, and when disaster events such as earthquakes or fires happen, or when power off or other severe faults occur on a working system, the working system is switched to a remote redundancy system to maintain a capability of providing an application service.
Currently, a redundancy process for a virtual machine (VM) on a first site side is as follows. A system administrator configures, on a disaster management function (DMF) on the first site side according to a service requirement, a VM or some VMs that are on the first site side and that require redundancy. The DMF on the first site side requests a local virtualization management function (VMF) to intercept input/output (IO) of a specified VM. The VMF on the first site side requests to run an IO catcher function (IOCF) for the specified VM to intercept the IO of the specified VM, and sends intercepted data to a local replication gateway function (RGF). The DMF on the first site side requests the RGF to send the received data to an RGF of a redundancy site.
The DMF on the first site side sends a generated redundancy request to a DMF of the redundancy site to request the DMF of the redundancy site to complete a redundancy configuration. The DMF of the redundancy site requests a local VMF to create a placeholder VM, and obtains an identifier of the placeholder VM. The placeholder VM is not running. The DMF of the redundancy site requests the local RGF to send received data of a peer VM (that is, the VM that requires redundancy on the first site side) to a specified local IO writer function (IOWF). The IOWF writes the data to a local VM (that is, the placeholder VM) for storage.
When a condition (for example, a case in which both an external circuit and an optical cable in an equipment room break during an earthquake) for a redundancy switchover is met on the first site side, the system administrator starts the redundancy switchover on the DMF of the redundancy site. A specific switchover process is as follows. The DMF of the redundancy site requests the local RGF to stop receiving peer data, the DMF of the redundancy site requests the local VMF to stop the IOWF device from writing data to the local VM, and the DMF of the redundancy site requests the local VMF to start the local VM.
It can be learned from the foregoing process that a redundancy process for a VM is controlled by a system administrator. That is, a DMF on a first site side queries a VMF for all VMs managed by the VMF and presents the VMs to the administrator. The administrator specifies a VM that requires redundancy. The DMF notifies the VM specified by the administrator to a local IOCF and a peer DMF such that the peer DMF performs redundancy on the specified VM. However, in public cloud business, tenants serve themselves. That is, the tenants can start or shut down a cloud service by themselves, without intervention of the administrator. As a result, the existing redundancy process cannot support a tenant self-service in the public cloud business.