SYSTEM AND METHOD FOR IMPLEMENTING CACHE CONSISTENT REGIONAL CLUSTERS

摘要

When multiple regional data clusters are used to store data in a system, maintaining cache consistency across different regions is important for providing a desirable user experience. In one embodiment, there is a master data cluster where all data writes are performed, and the writes are replicated to each of the slave data clusters in the other regions. Appended to the replication statements are invalidations for cache values for the keys whose values have been changed in the master data cluster. An apparatus in the master data cluster logs replication statements sent to the slave databases. When a slave database fails, the apparatus extracts the invalidations intended for the failed database and publishes the invalidations to a subscriber in the region of the failed database. The subscriber sends the invalidations to the local caches to cause stale data for those keys to be deleted from the caches.

主权项

1. An apparatus located in a first region of a system, the apparatus comprising:
a memory configured to store database updates performed on a first database cluster in the first region, wherein each database update corresponds to a key, and a first invalidation associated with the key is appended to the update; a processor configured to:
when a replica database in a second region remote from the first region has failed and cannot respond to database updates, publish a first subset of the first invalidations to a subscriber in the second region, wherein the first subset of the first invalidations are associated with keys having values stored in the replica database;wherein the subscriber is configured to send the first subset of the first invalidations to caches in the second region to cause values stored in the caches for the keys to be deleted.