
84 Large Scale and Big Data
model is well suited for distributed implementations as it doesn’t expose any mecha-
nism for detecting order of execution within a superstep, and all communication is
from superstep S to superstep S + 1. The ideas of Pregel have been cloned by many
open-source projects such as GoldenOrb,* Apache Hama,
†
and Apache Giraph.
‡
Both of Hama and Giraph are implemented to be launched as a typical Hadoop
job that can leverage the Hadoop infrastructure. Other large-scale graph processing
systems that have been introduced that neither follow the MapReduce model nor
leverage the Hadoop infrastructure include GRACE [130], Gra ...