On Mon, Jul 28, 2014 at 4:29 AM, Larry Xiao <xia...@sjtu.edu.cn> wrote:
> On 7/28/14, 3:41 PM, shijiaxin wrote: > >> There is a VertexPartition in the EdgePartition,which is created by >> >> EdgePartitionBuilder.toEdgePartition. >> >> and There is also a ShippableVertexPartition in the VertexRDD. >> >> These two Partitions have a lot of common things like index, data and >> >> Bitset, why is this necessary? >> >> There is a VertexPartition in the EdgePartition,which is created by > Is the VertexPartition in the EdgePartition, the Mirror Cache part? Yes, exactly. The primary copy of each vertex is stored in the VertexRDD using the index, values, and mask data structures, which together form a hash map. In addition, each partition of the VertexRDD stores the corresponding partition of the routing table to facilitate joining with the edges. The ShippableVertexPartition class encapsulates the vertex hash map along with a RoutingTablePartition. After joining the vertices with the edges, the edge partitions cache their adjacent vertices in the mirror cache. They use the VertexPartition for this, which provides only the hash map functionality and not the routing table. Ankur <http://www.ankurdave.com/>
