GraphLab 介绍
GraphLab 是一个机器学习平台，主要是图模型方面的计算。
GraphLab
是另一种有趣的MapReduce抽象实现，侧重机器学习算法的并行实现。GraphLab中，Map阶段定义了可以独立执行（在独立的主机上）的计算，Reduce阶段合并这些计算结果。
Designing and implementing efficient and provably correct parallel machine
learning (ML) algorithms can be very challenging. Existing high-level parallel
abstractions like MapReduce are often insufficiently expressive while low-
level tools like MPI and Pthreads leave ML experts repeatedly solving the same
design challenges. By targeting common patterns in ML, we developed GraphLab,
which improves upon abstractions like MapReduce by compactly expressing
asynchronous iterative algorithms with sparse computational dependencies while
ensuring data consistency and achieving a high degree of parallel performance.
