Cooperative log application

A replica database may receive a replication instruction from a master. The replica may maintain a version of a collection of data in database pages stored on a storage device. A replication thread may process the instruction. The replication thread may determine that an item affected by the instruction is located in a page that is both loaded into a memory buffer and subject to contention. The page may be modified with information indicating that the instruction has not been processed. A subsequent reader thread may, while processing a request to access the page, apply the instruction and complete processing of the request.