Vertexdriven

Vertexdriven refers to a computational model for processing graphs in which computation is initiated and driven primarily by the vertices of the graph. In this approach, each active vertex runs a user-defined program, updates its state, and communicates with its neighbors through messages or shared state in discrete iterations. Vertex-driven models are widely used in distributed graph processing systems and are often described as vertex-centric or vertex-programming.

In a typical vertex-driven system, computation proceeds in supersteps or iterations. During a superstep, every active vertex reads its current state, processes incoming messages, writes updates, and sends messages to neighboring vertices. A synchronization barrier ensures all messages are delivered before the next superstep. This abstraction emphasizes locality and parallelism at the vertex level.

Famous implementations include Google Pregel, Apache Giraph, GraphLab's vertex program API, and Apache Flink's Graph API (Gelly) that provide vertex-centric interfaces. These systems can support algorithms such as PageRank, connected components, shortest paths, and BFS.

Vertex-driven is commonly contrasted with edge-driven approaches, where computation is triggered by edges or messages traversing edges. Vertex-driven models are often easier to program for many classic graph algorithms, but can incur overhead for highly skewed graphs and require iterative synchronization. Variants include synchronous vs asynchronous execution, and different programming models such as gather-apply-scatter (GAS) or message-passing. Choice depends on workload characteristics, data locality, and infrastructure.