Читать книгу From Traditional Fault Tolerance to Blockchain - Wenbing Zhao - Страница 25

Maintainability refers to the capability of a system to evolve after it is deployed. Once a software fault is detected, it is desirable to be able to apply a patch that repairs the system without having to uninstall the existing system and then reinstall an updated system. The same patching/software update mechanism may be used to add new features or improve the performance of the existing system. Ideally, we want to be able to perform the software update without having to shutdown the running system (often referred to as live upgrade or live update), which is already a standard feature for many operating systems for patching non-kernal level components. Live upgrade has also be achieved via replication in some distributed systems [12].