US Patent 9451042 Scheduling and execution of DAG-structured computation on RDMA-connected clusters

A server and/or a client stores a metadata hash map that includes one or more entries associated with keys for data records stored in a cache on a server, wherein the data records comprise a directed acyclic graph (DAG), and the directed acyclic graph is comprised of a collection of one or more nodes connected by one or more edges, each of the nodes representing one or more tasks ordered into a sequence, and each of the edges representing one or more constraints on the nodes connected by the edges. Each of the entries stores metadata for a corresponding data record, wherein the metadata comprises a server-side remote pointer that references the corresponding data record stored in the cache. A selected data record is accessed using a provided key by: (1) identifying potentially matching entries in the metadata hash map using the provided key; (2) accessing data records stored in the cache using the server-side remote pointers from the potentially matching entries; and (3) determining whether the accessed data records match the selected data record using the provided key.