We present  CoScan , a scheduling framework that eliminates redundant processing in workflows that scan large batches of data in a map-reduce computing environment.  CoScan  merges Pig programs from multiple users at runtime to reduce I/O contention while adhering to soft deadline requirements in scheduling. This includes support for join workflows that operate on multiple data sources. Our solution maps well to workflows at many Internet companies which reuse data from a common set of inputs. Experiments on the PigMix data analytics benchmark exhibit orders of magnitude reduction in resource contention with minimal impact on latency.
['Xiaodan Wang', 'Christopher Olston', 'Anish Das Sarma', 'Randal C. Burns']
CoScan: cooperative scan sharing in the cloud