Abstract:
MapReduce is currently a parallel computing
framework for distributed processing of large-scale
data intensive application. The most important
performance metric is job execution time but it can
be seriously impacted by straggler machines.
Speculative execution is a common approach for this
problem by backing up slow tasks on alternative
machines. Some schedulers with speculative
execution have been proposed but they have some
weaknesses:(i) they cannot calculate the progress
rate accurately because the progress scores of the
phases are set to constant values which may be
totally different for heterogeneous environment, (ii)
they define the stragglers by specifying a static
threshold value which calculates the temporal
difference between an individual task and the
average task progression. To get the better
performance, this paper proposes an algorithm
identifying the stragglers by the more accurate
progress of each job based on its own historical
information and using a dynamic threshold value
adjusting the continuously varying environment
automatically.