MicroColor ServHA Cluster For Windows X64 dual-machine hot backup software (shared storage version)

ServHA is a dual-machine cluster product running on the Windows platform. It is responsible for managing two hosts running their own application systems. When the host or the software on the host fails, manual intervention is not required. The other host in the dual-machine cluster can detect the failed host through the heartbeat line and accurately and quickly transfer the application system of the original host to another host to continue running. This achieves uninterrupted operation of the entire system, thereby ensuring the normal external services of the entire system, and providing key business applications for enterprises and institutions 24 hours a day, 365 days a year. Provides strong protection.

The two servers (hosts) of the ServHA dual-machine system are connected to the disk array (shared storage) system. The user's operating system, application software and ServHA software are installed on the two hosts respectively. Shared data such as databases are stored on the storage system. A heartbeat connection is established between the two hosts through a private (or public) network.

After the configured system host starts working, the ServHA service starts to monitor the system. Through the heartbeat connection, the ServHA service on each host can monitor the status of the other host. When the working host fails, the heartbeat information will change, and this change can be captured by the ServHA service through the heartbeat connection.

When ServHA captures this change, it will control the system to perform host switching. That is, the backup machine starts the same application as the working host to take over the work of the working host (including providing TCP/IP network services, storage system access and other services) and issues an alarm to prompt managers to repair the faulty host.

After the repair is completed, you can switch back automatically or manually according to the ServHA settings, or you can not switch back. At this time, the repaired host will be used as a backup machine, and the dual-machine system will continue to work.

The key to ServHA's fault tolerance function is that the host is transparent to the client. When a system error occurs and a switch is performed, the switch of the host does not appear to the client to have changed, and all host-based applications will still run normally. ServHA uses IP drift technology to achieve this function.

The client communicates with the working host through the virtual address. Regardless of whether the system switches or not, the virtual address always points to the working host.

When performing network services, ServHA provides a logical virtual address, and any client only needs to use this virtual address when requesting services. During normal operation, virtual addresses and network services are provided by the main server. When the main server fails, ServHA will transfer the virtual address to the network card of another server to continue to provide network services.

After the switchover is completed, it appears to the client that the system has not failed and network services can still be used. In addition to IP addresses, ServHA can also provide virtual computer aliases for client access. For database services, when the main server fails, another server will automatically take over and start the database and applications at the same time, so that the user database can operate normally.