Data reading method and system and storage medium

A cache mirror image system, wherein the cache mirror image system comprises a first node and a second node which are mirror images of each other, the first node is a newly added node, and the second node is a node which has not failed in an original cache mirror pair, when any one node in the original cache mirror image pair fails, the first node is added to constitute a cache mirror image pair with the second node, and the first node comprises:

• a memory used for storing computer-readable instructions;
• a processor used for implementing operations comprising:
• in response to the first node receiving a data reading request, determining a current state of the first node;
• in response to the current state of the first node being a mirror image recombination state, and the request data corresponding to the data reading request hitting the cache of the first node, reading the request data from the cache of the first node;
• in response to the current state of the first node being the mirror image recombination state, and the request data corresponding to the data reading request missing the cache of the first node, reading the request data from a cache of the second node;
• and
• feeding the request data back to a request terminal;
• wherein the operations further comprise:
• in response to the current state of the first node being a mirror image recombination completion state, reading the request data from the cache of the first node, and feeding the request data back to the request terminal;
• wherein the data reading method further comprises:
• in response to the current state of the first node being the mirror image recombination state, reading unique cache data from the cache of the second node;
• and
• writing the unique cache data into the cache of the first node.

A non-transitory computer-readable storage medium, wherein the computer-readable storage medium stores computer-readable instructions applied to a cache mirror image pair, the cache mirror image pair comprises a first node and a second node which are mirror images of each other, the first node is a newly added node, and the second node is a node which has not failed in an original cache mirror pair, when any one node in the original cache mirror image pair fails, the first node is added to constitute the cache mirror image pair with the second node, and the computer-readable instructions, when executed by a processor, implement operations comprising:

• in response to the first node receiving a data reading request, determining a current state of the first node;
• in response to the current state of the first node being a mirror image recombination state, and the request data corresponding to the data reading request hitting the cache of the first node, reading the request data from the cache of the first node;
• in response to the current state of the first node being the mirror image recombination state, and the request data corresponding to the data reading request missing the cache of the first node, reading the request data from a cache of the second node;
• and
• feeding the request data back to a request terminal;
• wherein the operations further comprise:
• in response to the current state of the first node being a mirror image recombination completion state, reading the request data from the cache of the first node, and feeding the request data back to the request terminal;
• wherein the data reading method further comprises:
• in response to the current state of the first node being the mirror image recombination state, reading unique cache data from the cache of the second node;
• and
• writing the unique cache data into the cache of the first node.