Item Pager Expiry Pager Checkpoint Manager Cache . . H Partition ash Tables Fetcher Scheduler Reader IO Writer IO Generic Tasks Flusher The Key Value Data Service The KV "Data Plane" of a Couchbase cluster: • High performance memcached DNA • With data partitioning ("vbuckets") • Sub-Document operations • Authentication / RBAC And also... • Asynch task workers and scheduler • For I/O: persistence, backfill • For expiry & cleanup • For replication • The source of Database Change Protocol • A consumer of Database Change Protocol 30 Authentication