scholarly journals Timely Reliability Analysis of Virtual Machines Considering Migration and Recovery in an Edge Server

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 93
Author(s):  
Kangkai Liu ◽  
Linhan Guo ◽  
Yu Wang ◽  
Xianyu Chen
Keyword(s):  
Virtual Machines ◽  
First Passage Time ◽  
Passage Time ◽  
Edge Computing ◽  
Delay Constraint ◽  
Vm Migration ◽  
Delay Sensitive ◽  
End To End Delay ◽  
End To End ◽  
The Impact

For the edge computing network, whether the end-to-end delay satisfies the delay constraint of the task is critical, especially for delay-sensitive tasks. Virtual machine (VM) migration improves the robustness of the network, whereas it also causes service downtime and increases the end-to-end delay. To study the influence of failure, migration, and recovery of VMs, we define three states for the VMs in an edge server and build a continuous-time Markov chain (CTMC). Then, we develop a matrix-geometric method and a first passage time method to obtain the VMs timely reliability (VTR) and the end-to-end timely reliability (ETR). The numerical results are verified by simulation based on OMNeT++. Results show that VTR is a monotonic function of the migration rate and the number of VMs. However, in some cases, the increase in task VMs (TVMs) may conversely decrease VTR, since more TVMs also brings about more failures in a given time. Moreover, we find that there is a trade-off between TVMs and backup VMs (BVMs) when the total number of VMs is limited. Our findings may shed light on understanding the impact of VM migration on end-to-end delay and designing a more reliable edge computing network for delay-sensitive applications.

Simulated Performance of SCTP and TFRC Over MANETs

2020 ◽  
Vol 16 (2) ◽  
pp. 69-83
Author(s):  
Ali H. Wheeb ◽  
Dimitris N. Kanellopoulos
Keyword(s):  
Multimedia Streaming ◽  
Traffic Load ◽  
Delivery Ratio ◽  
Transmission Protocol ◽  
Streaming Applications ◽  
Simulated Performance ◽  
End To End Delay ◽  
End To End ◽  
The Impact ◽  
Better Than

Mobile ad-hoc networks (MANETs) are composed of mobile nodes communicating through wireless medium, without any fixed centralized infrastructure. Providing quality of service (QoS) support to multimedia streaming applications over MANETs is vital. This paper focuses on QoS support, provided by the stream control transmission protocol (SCTP) and the TCP-friendly rate control (TFRC) protocol to multimedia streaming applications over MANETs. In this study, three QoS parameters were considered jointly: (1) packet delivery ratio (PDR), (2) end-to-end delay, (3) and throughput. Specifically, the authors analyzed and compared the simulated performance of the SCTP and TFRC transport protocols for delivering multimedia streaming over MANETs. Two simulation scenarios were conducted to study the impact of traffic load and node speed (mobility) to their performance. Based on the simulation results, the authors found that the PDR and the end-to-end delay of TFRC are slightly better than those of SCTP in both scenarios. Additionally, the performance of SCTP is significantly better than TFRC in terms of throughput.

scholarly journals Impact of Direction Parameter in Performance of Modified AODV in VANET

2020 ◽  
Vol 9 (3) ◽  
pp. 40 ◽  
Author(s):  
Afsana Ahamed ◽  
Hamid Vakilzadian
Keyword(s):  
Routing Protocol ◽  
Packet Loss ◽  
Routing Protocols ◽  
Ad Hoc Network ◽  
Ad Hoc ◽  
End To End Delay ◽  
Distance Vector ◽  
End To End ◽  
Route Request ◽  
The Impact

A vehicular ad hoc network (VANET) is a technology in which moving cars are used as routers (nodes) to establish a reliable mobile communication network among the vehicles. Some of the drawbacks of the routing protocol, Ad hoc On-Demand Distance Vector (AODV), associated with VANETs are the end-to-end delay and packet loss. We modified the AODV routing protocols to reduce the number of route request (RREQ) and route reply (RREP) messages by adding direction parameters and two-step filtering. The two-step filtering process reduces the number of RREQ and RREP packets, reduces the packet overhead, and helps to select the stable route. In this study, we show the impact of the direction parameter in reducing the end-to-end delay and the packet loss in AODV. The simulation results show a 1.4% reduction in packet loss, an 11% reduction in the end-to-end delay, and an increase in throughput.

scholarly journals A Virtual Machine Migration Strategy Based on the Relevance of Services against Side-Channel Attacks

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Ji-Ming Chen ◽  
Shi Chen ◽  
Xiang Wang ◽  
Lin Lin ◽  
Li Wang
Keyword(s):  
Internet Of Things ◽  
Virtual Machine ◽  
Virtual Machines ◽  
Edge Computing ◽  
Security And Privacy ◽  
Side Channel ◽  
Virtual Machine Migration ◽  
Side Channel Attacks ◽  
Migration Strategy ◽  
Vm Migration

With the rapid development of Internet of Things technology, a large amount of user information needs to be uploaded to the cloud server for computing and storage. Side-channel attacks steal the private information of other virtual machines by coresident virtual machines to bring huge security threats to edge computing. Virtual machine migration technology is currently the main way to defend against side-channel attacks. VM migration can effectively prevent attackers from realizing coresident virtual machines, thereby ensuring data security and privacy protection of edge computing based on the Internet of Things. This paper considers the relevance between application services and proposes a VM migration strategy based on service correlation. This strategy defines service relevance factors to quantify the degree of service relevance, build VM migration groups through service relevance factors, and effectively reduce communication overhead between servers during migration, design and implement the VM memory migration based on the post-copy method, effectively reduce the occurrence of page fault interruption, and improve the efficiency of VM migration.

scholarly journals First-passage time asymptotics over moving boundaries for random walk bridges

2018 ◽  
Vol 55 (2) ◽  
pp. 627-651 ◽  
Author(s):  
Fiona Sloothaak ◽  
Vitali Wachtel ◽  
Bert Zwart
Keyword(s):  
Random Walk ◽  
Moving Boundary ◽  
First Passage Time ◽  
Passage Time ◽  
Finite Variance ◽  
Tail Behavior ◽  
First Passage ◽  
The Impact ◽  
Return Point ◽  
Asymptotic Tail

Abstract We study the asymptotic tail behavior of the first-passage time over a moving boundary for a random walk conditioned to return to zero, where the increments of the random walk have finite variance. Typically, the asymptotic tail behavior may be described through a regularly varying function with exponent -½, where the impact of the boundary is captured by the slowly varying function. Yet, the moving boundary may have a stronger effect when the tail is considered at a time close to the return point of the random walk bridge, leading to a possible phase transition depending on the order of the distance between zero and the moving boundary.

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