US Patent 11782874 Bottom-up pre-emptive cache update in a multi-level redundant cache system

Providing cache updates in a multi-node system through a service component between a lower level component and a next higher level component by maintaining a ledger storing an incrementing number indicating a present state of the datasets in a cache of the lower level component. The service component receives a data request to the lower level component from the higher level component including an appended last entry number accessed by the higher level component. It determines if the appended last entry number matches a current entry number in the ledger for any requested dataset. No match indicates that some data in the higher level component cache is stale. It then sends updated information for the stale data to the higher level component. The higher level component invalidates its cache entries and updates the appended last entry number to match a current entry number in the ledger.