METHOD AND APPARATUS FOR UPGRADING A DISTRIBUTED STORAGE SYSTEM

Embodiments of the disclosure provide a method and apparatus for upgrading a distributed storage system, and the disclosure relates to the field of distributed computer technology. In the disclosure, a client sends write requests regarding the same to-be-written data to a plurality of data servers at the same time; then how many data servers the to-be-written data is successfully written into is analyzed; it is determined whether the number of the successful writes is greater than a pre-defined number; and first feedback information or second feedback information is sent to each data server having a successful write according to the determining result. The data server then determines whether it is in an upgradeable state or a non-upgradeable state according to the received first feedback information or second feedback information. Based on the state of the data server, an upgrade control server may select to notify, in a rolling manner, the data server to perform an upgrade operation. Therefore, a shorter response time of the system to the client is ensured without having to stop the high-level services, and data reliability is improved, significantly reducing the risk of user data loss.