Data reading method, apparatus, and system, avoiding version rollback issues in distributed system

A distributed system, comprising a master node and a plurality of slave nodes,

• a first slave node of the plurality of slave nodes is configured to:
• receive a data read request sent by a terminal, wherein the data read request comprises a logical address of target data;
• locally search, based on the logical address, the first slave node for a latest version of the target data;
• and
• when the latest version of the target data has been stored in each of the plurality of slave nodes, send the latest version of the target data to the terminal,
• wherein the first slave node is further configured to:
• after finding the latest version of the target data, search indication information sent by the master node;
• detect whether the indication information includes an index of the target data and a version number of the latest version of the target data;
• determine the latest version of the target data is stored in each of the plurality of slave nodes in response to a detecting result that the indication information includes the index of the target data and the version number of the latest version of the target data.