 BEIJING, Sept. 25, 2021 GLOBE NEWSWIRE -- 21Vianet Group, Inc. Nasdaq: VNET 21Vianet or the Company, a leading carrier- and cloud-neutral Internet data center services provider in China, today announced that Mr. Chunfeng Cai, the Companys Chief Operating Officer COO, has decided to resign from his current post and leave the Company due to personal reasons, effective on October 1, 2021. 