935 research outputs found
Fault-Tolerant scheduling for scientific workflows in cloud environments
Executing clustered tasks has proven to be an efficient method to improve the computation of Scientific Workflows (SWf) on clouds. However, clustered tasks has a higher probability of suffering from failures than a single task. Therefore, fault tolerance in cloud computing is extremely essential while running large-scale scientific applications. In this paper, a new heuristic called Cluster based Heterogeneous Earliest Finish Time (CHEFT) algorithm to enhance the scheduling and fault tolerance mechanism for SWf in highly distributed cloud environments is proposed. To mitigate the failure of clustered tasks, this algorithm uses idle-Time of the provisioned resources to resubmit failed clustered tasks for successful execution of SWf. Experimental results show that the proposed algorithm have convincing impact on the SWf executions and also drastically reduce the resource waste compared to existing task replication techniques. A trace based simulation of five real SWf shows that this algorithm is able to sustain unexpected task failures with minimal cost and makespan. © 2017 IEEE
A Bag-of-Tasks Scheduler Tolerant to Temporal Failures in Clouds
Cloud platforms have emerged as a prominent environment to execute high
performance computing (HPC) applications providing on-demand resources as well
as scalability. They usually offer different classes of Virtual Machines (VMs)
which ensure different guarantees in terms of availability and volatility,
provisioning the same resource through multiple pricing models. For instance,
in Amazon EC2 cloud, the user pays per hour for on-demand VMs while spot VMs
are unused instances available for lower price. Despite the monetary
advantages, a spot VM can be terminated, stopped, or hibernated by EC2 at any
moment.
Using both hibernation-prone spot VMs (for cost sake) and on-demand VMs, we
propose in this paper a static scheduling for HPC applications which are
composed by independent tasks (bag-of-task) with deadline constraints. However,
if a spot VM hibernates and it does not resume within a time which guarantees
the application's deadline, a temporal failure takes place. Our scheduling,
thus, aims at minimizing monetary costs of bag-of-tasks applications in EC2
cloud, respecting its deadline and avoiding temporal failures. To this end, our
algorithm statically creates two scheduling maps: (i) the first one contains,
for each task, its starting time and on which VM (i.e., an available spot or
on-demand VM with the current lowest price) the task should execute; (ii) the
second one contains, for each task allocated on a VM spot in the first map, its
starting time and on which on-demand VM it should be executed to meet the
application deadline in order to avoid temporal failures. The latter will be
used whenever the hibernation period of a spot VM exceeds a time limit.
Performance results from simulation with task execution traces, configuration
of Amazon EC2 VM classes, and VMs market history confirms the effectiveness of
our scheduling and that it tolerates temporal failures
The Contemporary Affirmation of Taxonomy and Recent Literature on Workflow Scheduling and Management in Cloud Computing
The Cloud computing systemspreferred over the traditional forms of computing such as grid computing, utility computing, autonomic computing is attributed forits ease of access to computing, for its QoS preferences, SLA2019;s conformity, security and performance offered with minimal supervision. A cloud workflow schedule when designed efficiently achieves optimalre source sage, balance of workloads, deadline specific execution, cost control according to budget specifications, efficient consumption of energy etc. to meet the performance requirements of today2019; svast scientific and business requirements. The businesses requirements under recent technologies like pervasive computing are motivating the technology of cloud computing for further advancements. In this paper we discuss some of the important literature published on cloud workflow scheduling
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