1. In a system comprising a client computing device (client) coupled to a server and multiple data storage nodes, a computer-implemented method for collection-based replication comprising: generating, by a node of the multiple data storage nodes, a replica of multiple replicas of a collection, the collection being a unit of data placement, access, replication, and repair in the system, other nodes of the multiple data storage nodes each comprising a respective replica of the multiple replicas; and determining, by the node, whether an object received directly from the client has been fully replicated by the other nodes in each replica of the multiple replicas, the determining being made by the node independent of any information on the server as to whether the object has been successfully replicated in the system.