Concept:
System-of-record: a system record, which is the original location of the data source. For example, the common database, is the actual storage data exercise, referred to as SoR.
Cache: snapshot data recorded by the system. The Cache access speed is faster than SoR. The purpose of caching is to improve Cache hit ratio, enable hotspot data to be cached, and reduce the number of times that source data is returned to SoR.
Back source: is to return to the data source query data, cache does not hit the SoR query data is back to the source.
Usage scenarios
Read scenario: The system reads data from the cache. If it reads data, the system returns it. If it does not read data in the cache, the system reads data from the source to the SoR, and then writes the data to the cache for the next cache.
Write scenario: Data is written to the SoR system first. After data is written to the SoR system, data is synchronized to the cache immediately.
Update scenario: Update SoR data, delete cached data, and write the data to the cache. Or after the SoR is updated, the system sets the expiration of the cache data, and the SoR will be read by the system next time. After reading, the SoR will be written to the cache.