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Device Stand-by Management Scheme of IoT:
A Framework for Dealing with
Real-world Device Fault Risk
In City Platform as a Service
IMIS2018, Matsue, Japan
Toshihiko Yamakami
CTO Team, ACCESS
Toshihiko.Yamakami@access-company.com
2018/07
Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 1 / 26
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Outline
Background
Related Work
Research Method
Stand-by Mechanism of Edge Computing
Requirements
Stand-by Mechanism
Simulation
Parameters
Simulation Results
Discussion
Advantages of the Proposed Model
Limitations
Conclusion
Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 2 / 26
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Background
Research Purpose
The aim of this research is to develop a framework to enable stand by
mechanism to ensure service availability at a device fault.
Background
The increase of number of smart devices attract attention in edge
computing. Efficient use of resources is an important topic in edge
computing.
There are two types of edge computing: heavy edge computing and
lightweight edge computing. And the growth will present opportunities
of lightweight edge computing because a large part of IoT growth will
be attributed to limited resource devices.
Many real-world IoT applications have challenges of hardware faults. In
the Cyber-Physical system perspective, it is a challenge to deal with.
Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 3 / 26
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Related Work
a) task migration algorithms
a resource allocation approach for a hard real-time guarantee automotive system
[Dziurzanski15], complex event processing in operator migration of a
device-to-device system[Dwarakanath16] real time task migration in Apache
Storm[Yang15] task migration for network utilization[Ottenwalder15]
b) migration programming models and middleware
ThingsJS, a Javascript-based middleware platform [Gascon-Samson17], a
fine-grained edge off-loading architecture FADES [Cozzolino17]
c) collaborative processing and system issues
distribute data flow for collaborative processing of devices with different owners
[Giang15]
The originality of this paper lies in its development of a stand-by-based
migration scheme for IoT.
Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 4 / 26
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Overview of CPaaS.io
Smart City Innovation is the goal of the CPaaS.io joint R&D project
between Europe and Japan starting from 2016.
To achieve this, the CPaaS.io platform combines the capabilities of
the Internet of Things (IoT), big data analytics and cloud service
provisioning with Open Government Data and Linked Data
approaches.
CPaaS.io hosts multiple projects in different cities in Europe and
Japan, e.g. Utrecht, Amsterdam, Tokyo, Sapporo, and Yokosuka.
URL: https://cpaas.bfh.ch/ CPaaS.io – City Platform as a Service
Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 5 / 26
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Research Method
Identifying real-world IoT migration contexts,
Developing a framework of lightweight edge computing,
Developing a stand-by-based migration scheme for edge computing
Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 6 / 26
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Applicability of task migration of u2 architecture
dynamic static
(real-time, automatic) (planned, semi-
automatic)
Heavy-edge module N.A. N.A.
Migration
Lightweight edge module N.A. u2
Migration
u2 architecture is ucode version 2-based. Ucode is a 128-bit identifier system standardized
ITU-T H.642.1, proposed by University of Tokyo.
Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 7 / 26
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Requirements of edge computing
Requirement Description
Load balancing Computational load is distributed among multiple
edge nodes to ensure throughput.
Low latency Computational load is performed at edge nodes not
in the cloud, to ensure low latency.
Privacy preservation Sensitive information is maintained in devices and
edges to ensure protected access.
Off-loading Computational load is distributed to another avail-
able edge node to ensure service availability of
front-end node.
Fault-tolerance Alternate device is provided to ensure continued
service at a fault in a device.
Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 8 / 26
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Characteristics of Lightweight Edge Computing
Item Description
Binary migration Migration is done by binary code.
State-less migration Limited or no capability of processing states among
lightweight edge nodes.
Front-end availability it is crucial to maintain front-end availability
Data loss tolerance Data loss is prohibiting, however, it is better than
no front-end availability.
For example, when a fault take places at random and the average interval is 90 days, more
than 1 % fault occurs within 1 day from the previous fault in a Poisson distribution case.
Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 9 / 26
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Modified Definition of Task Migration of Edge Computing
Migration Load-balancing or off-loading of computational re-
quirements to multiple available edge nodes
Modified migration Remove the computational requirements from orig-
inal device and relocate them to a stand-by device
in order to secure the continuity of a service.
Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 10 / 26
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Stand-by Mechanism
working -
stand-by -
monitor
controller
?
device description
?
Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 11 / 26
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Example of Control Flow
device
controller (node)
- log collection
for predictive maintenance
6
calculation of
fault/penalty
Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 12 / 26
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Task and Device Descriptions
Task Description
Internal Requirements
External Requirements
Device Description
- Static
Properties
Dynamic
Properties
Item Description
Availability target Required range of availability ratio as a service
system.
Stand-by Costs Costs (hardware, software, networking, battery)
for stand-by.
Dependency External dependency to execute a task.
Fault characteristics Characteristics (severity, frequency) of faults.
Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 13 / 26
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Device Status
Status Description
Normal Normal status. No standby is provided. When at fault,
normal reconfiguration operation will be performed.
Dual Dual working status. Multiple devices are working to
ensure fault tolerance.
Cold Standby A stand-by device is available, but it is not ready for
instant switch.
Hot Standby A stand-by device is available, and it is ready for instant
switch.
Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 14 / 26
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Binary Code Allocation
Status Description
On device Multiple binary images are maintained on a device.
On cloud A binary image is maintained in cloud, and transferred
on demand.
On peer device A binary image is maintained on a peer device.
On edge A binary image is maintained in an edge node.
Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 15 / 26
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Examples of Down Time Requirements
Application type Description
Chemical plant sen-
sors
Industrial chemical plant sensors require a down
time less than 60 seconds.
Real-time traffic mon-
itors
Real-time traffic monitors require a down time less
than 5 minutes.
Climate logging sen-
sors
Climate logging sensors require a down time less
than an hour.
Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 16 / 26
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Simulation Parameters and Output
Item Description
Stand-by number 1
Number of Trial 10000
Battery consumption normal: cold-start: hot-start: dual = 1.0 : 1.1 :
1.6 : 2.8
Switch time normal 15 minutes, cold standby 1 minute
Average fault interval 30 days (Poisson distribution)
Output Description
Latency Average latency to respond a service request.
Availability Average ratio to be ready to serve a request.
Costs Costs of devices and operation to serve a request.
The simulation is done in R-3.3.3 for Windows(64bit).
Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 17 / 26
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Five Cases in Comparison
Case Description
Regular No stand by. When a device fails, an alternative
device is invoked after the detection.
Cold Standby An alternate device is usable, but not ready for
working.
Managed Standby A stand-by is initiated according to observed device
characteristics.
Hot Standby An alternate device is always in standby to replace
a failed device.
Dual Always two devices are working and synchronized.
One fault does not disrupt continuous operation.
Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 18 / 26
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Managed Standby Flow
after initiation or a fault, a standby device is in a cold standby status.
according to the previous fault records, a transition time is set.
when the transition time passes, the standby devices becomes a hot
standby status.
when a fault occurs before the transition time, the standby device will
be activated from the cold standby status.
Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 19 / 26
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Simulation Conditions
Conditions Description
Switch time The switch times for the hot standby mode and the
dual mode are negligible. tn for the normal mode
and tc for the cold standby mode.
Battery-based defect Battery status is not considered to influence defect
ratios.
Fault ratio Fault ratios are assumed to be random (Poisson
distribution arrival).
The same in all modes (No impact from standby or
dual modes.)
Average fault interval is 30 days.
Operation complexity Operation complexity of the dual mode is negligi-
ble.
Battery overhead Percentage to the normal mode, 1+bc for the cold
standby mode, 1 + bh for the hot standby mode,
1 + bd for the dual mode.
Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 20 / 26
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Battery Consumption (normal mode as 100
Relative
Battery
Consumption
100
200
normal cold
standby
hot
standby
dual managed
standby
Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 21 / 26
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Relative Downtime (normal mode as 100)
Relative
Downtime
100
normal cold
standby
hot
standby
dual managed
standby
Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 22 / 26
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Advantages of the Proposed Approach
The author proposes a hybrid approach of managed standby. The approach
uses a combination of cold-standby and hot-standby using data-based
proactive management of devices.
The author performs a preliminary simulation to compare the five modes,
normal, cold-standby, hot-standby, dual, and managed standby.
Initial simulation results are promising to pursue proactive management of
IoT devices.
The use of relatively inexpensive common CPU boards as a hot-standby or
cold-standby for fault situations may be an important consideration in the
future where the IoT computing is indispensable for the society. It is
conceptually similar to RAID (Redundant Array of Inexpensive Disks) in hard
disk.
Depending on a stringent requirement for continuity hot-standby or even a
dual configuration may be requested. But our simulation shows that a
proactive managed standby may bring in a cost-effective solution.
Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 23 / 26
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Limitations
This paper is exploratory and at its early stage.
Quantitative evaluation of the proposed method is not enough and requires
further examination. The proposed control mechanism requires further
validation with real-world test data in multiple use cases.
Requirements of maximum downtime vary and require case-by-case
examination.
The parameters of simulation are ad hoc, and not based on the real-world
data.
Penalties of managed standby is context-dependent and requires further
consideration at deployment.
Software-managed fault tolerance of IoT devices is a relatively new field and
requires future evaluation.
Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 24 / 26
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Conclusion
For lightweight edge, it is important to deal with device failures rather than
management of complicated computing resources with off-loading. The
author defines the binary-level stand-by management is a part of task
migration in lightweight edge computing.
The author proposes a managed standby mechanism to make hybrid use of
multiple standby mechanisms to dynamically adapt the device management.
It facilitates the use of accumulated fault history data to provide proactive
management of devices.
The author performs a preliminary simulation to evaluate the advantages of
managed standby with combined cold standby and hot standby modes. The
simulation results show the managed standby method is promising
considering the hybrid characteristics of cold-standby and hot-standby.
This is an encouraging result for future exploration of proactive managed
standby in smart city services. The future research include data-mining-based
proactive management and deep learning of long-term fault characteristics
using aggregated use of IoT maintenance history data.
Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 25 / 26
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Thank You for Your Attention!
Questions?
Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 26 / 26

Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world Device Fault Risk In City Platform as a Service

  • 1.
    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Device Stand-by ManagementScheme of IoT: A Framework for Dealing with Real-world Device Fault Risk In City Platform as a Service IMIS2018, Matsue, Japan Toshihiko Yamakami CTO Team, ACCESS Toshihiko.Yamakami@access-company.com 2018/07 Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 1 / 26
  • 2.
    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Outline Background Related Work Research Method Stand-byMechanism of Edge Computing Requirements Stand-by Mechanism Simulation Parameters Simulation Results Discussion Advantages of the Proposed Model Limitations Conclusion Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 2 / 26
  • 3.
    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Background Research Purpose The aimof this research is to develop a framework to enable stand by mechanism to ensure service availability at a device fault. Background The increase of number of smart devices attract attention in edge computing. Efficient use of resources is an important topic in edge computing. There are two types of edge computing: heavy edge computing and lightweight edge computing. And the growth will present opportunities of lightweight edge computing because a large part of IoT growth will be attributed to limited resource devices. Many real-world IoT applications have challenges of hardware faults. In the Cyber-Physical system perspective, it is a challenge to deal with. Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 3 / 26
  • 4.
    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Related Work a) taskmigration algorithms a resource allocation approach for a hard real-time guarantee automotive system [Dziurzanski15], complex event processing in operator migration of a device-to-device system[Dwarakanath16] real time task migration in Apache Storm[Yang15] task migration for network utilization[Ottenwalder15] b) migration programming models and middleware ThingsJS, a Javascript-based middleware platform [Gascon-Samson17], a fine-grained edge off-loading architecture FADES [Cozzolino17] c) collaborative processing and system issues distribute data flow for collaborative processing of devices with different owners [Giang15] The originality of this paper lies in its development of a stand-by-based migration scheme for IoT. Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 4 / 26
  • 5.
    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Overview of CPaaS.io SmartCity Innovation is the goal of the CPaaS.io joint R&D project between Europe and Japan starting from 2016. To achieve this, the CPaaS.io platform combines the capabilities of the Internet of Things (IoT), big data analytics and cloud service provisioning with Open Government Data and Linked Data approaches. CPaaS.io hosts multiple projects in different cities in Europe and Japan, e.g. Utrecht, Amsterdam, Tokyo, Sapporo, and Yokosuka. URL: https://cpaas.bfh.ch/ CPaaS.io – City Platform as a Service Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 5 / 26
  • 6.
    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Research Method Identifying real-worldIoT migration contexts, Developing a framework of lightweight edge computing, Developing a stand-by-based migration scheme for edge computing Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 6 / 26
  • 7.
    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Applicability of taskmigration of u2 architecture dynamic static (real-time, automatic) (planned, semi- automatic) Heavy-edge module N.A. N.A. Migration Lightweight edge module N.A. u2 Migration u2 architecture is ucode version 2-based. Ucode is a 128-bit identifier system standardized ITU-T H.642.1, proposed by University of Tokyo. Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 7 / 26
  • 8.
    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Requirements of edgecomputing Requirement Description Load balancing Computational load is distributed among multiple edge nodes to ensure throughput. Low latency Computational load is performed at edge nodes not in the cloud, to ensure low latency. Privacy preservation Sensitive information is maintained in devices and edges to ensure protected access. Off-loading Computational load is distributed to another avail- able edge node to ensure service availability of front-end node. Fault-tolerance Alternate device is provided to ensure continued service at a fault in a device. Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 8 / 26
  • 9.
    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Characteristics of LightweightEdge Computing Item Description Binary migration Migration is done by binary code. State-less migration Limited or no capability of processing states among lightweight edge nodes. Front-end availability it is crucial to maintain front-end availability Data loss tolerance Data loss is prohibiting, however, it is better than no front-end availability. For example, when a fault take places at random and the average interval is 90 days, more than 1 % fault occurs within 1 day from the previous fault in a Poisson distribution case. Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 9 / 26
  • 10.
    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Modified Definition ofTask Migration of Edge Computing Migration Load-balancing or off-loading of computational re- quirements to multiple available edge nodes Modified migration Remove the computational requirements from orig- inal device and relocate them to a stand-by device in order to secure the continuity of a service. Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 10 / 26
  • 11.
    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Stand-by Mechanism working - stand-by- monitor controller ? device description ? Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 11 / 26
  • 12.
    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Example of ControlFlow device controller (node) - log collection for predictive maintenance 6 calculation of fault/penalty Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 12 / 26
  • 13.
    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Task and DeviceDescriptions Task Description Internal Requirements External Requirements Device Description - Static Properties Dynamic Properties Item Description Availability target Required range of availability ratio as a service system. Stand-by Costs Costs (hardware, software, networking, battery) for stand-by. Dependency External dependency to execute a task. Fault characteristics Characteristics (severity, frequency) of faults. Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 13 / 26
  • 14.
    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Device Status Status Description NormalNormal status. No standby is provided. When at fault, normal reconfiguration operation will be performed. Dual Dual working status. Multiple devices are working to ensure fault tolerance. Cold Standby A stand-by device is available, but it is not ready for instant switch. Hot Standby A stand-by device is available, and it is ready for instant switch. Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 14 / 26
  • 15.
    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Binary Code Allocation StatusDescription On device Multiple binary images are maintained on a device. On cloud A binary image is maintained in cloud, and transferred on demand. On peer device A binary image is maintained on a peer device. On edge A binary image is maintained in an edge node. Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 15 / 26
  • 16.
    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Examples of DownTime Requirements Application type Description Chemical plant sen- sors Industrial chemical plant sensors require a down time less than 60 seconds. Real-time traffic mon- itors Real-time traffic monitors require a down time less than 5 minutes. Climate logging sen- sors Climate logging sensors require a down time less than an hour. Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 16 / 26
  • 17.
    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Simulation Parameters andOutput Item Description Stand-by number 1 Number of Trial 10000 Battery consumption normal: cold-start: hot-start: dual = 1.0 : 1.1 : 1.6 : 2.8 Switch time normal 15 minutes, cold standby 1 minute Average fault interval 30 days (Poisson distribution) Output Description Latency Average latency to respond a service request. Availability Average ratio to be ready to serve a request. Costs Costs of devices and operation to serve a request. The simulation is done in R-3.3.3 for Windows(64bit). Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 17 / 26
  • 18.
    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Five Cases inComparison Case Description Regular No stand by. When a device fails, an alternative device is invoked after the detection. Cold Standby An alternate device is usable, but not ready for working. Managed Standby A stand-by is initiated according to observed device characteristics. Hot Standby An alternate device is always in standby to replace a failed device. Dual Always two devices are working and synchronized. One fault does not disrupt continuous operation. Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 18 / 26
  • 19.
    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Managed Standby Flow afterinitiation or a fault, a standby device is in a cold standby status. according to the previous fault records, a transition time is set. when the transition time passes, the standby devices becomes a hot standby status. when a fault occurs before the transition time, the standby device will be activated from the cold standby status. Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 19 / 26
  • 20.
    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Simulation Conditions Conditions Description Switchtime The switch times for the hot standby mode and the dual mode are negligible. tn for the normal mode and tc for the cold standby mode. Battery-based defect Battery status is not considered to influence defect ratios. Fault ratio Fault ratios are assumed to be random (Poisson distribution arrival). The same in all modes (No impact from standby or dual modes.) Average fault interval is 30 days. Operation complexity Operation complexity of the dual mode is negligi- ble. Battery overhead Percentage to the normal mode, 1+bc for the cold standby mode, 1 + bh for the hot standby mode, 1 + bd for the dual mode. Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 20 / 26
  • 21.
    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Battery Consumption (normalmode as 100 Relative Battery Consumption 100 200 normal cold standby hot standby dual managed standby Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 21 / 26
  • 22.
    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Relative Downtime (normalmode as 100) Relative Downtime 100 normal cold standby hot standby dual managed standby Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 22 / 26
  • 23.
    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Advantages of theProposed Approach The author proposes a hybrid approach of managed standby. The approach uses a combination of cold-standby and hot-standby using data-based proactive management of devices. The author performs a preliminary simulation to compare the five modes, normal, cold-standby, hot-standby, dual, and managed standby. Initial simulation results are promising to pursue proactive management of IoT devices. The use of relatively inexpensive common CPU boards as a hot-standby or cold-standby for fault situations may be an important consideration in the future where the IoT computing is indispensable for the society. It is conceptually similar to RAID (Redundant Array of Inexpensive Disks) in hard disk. Depending on a stringent requirement for continuity hot-standby or even a dual configuration may be requested. But our simulation shows that a proactive managed standby may bring in a cost-effective solution. Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 23 / 26
  • 24.
    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Limitations This paper isexploratory and at its early stage. Quantitative evaluation of the proposed method is not enough and requires further examination. The proposed control mechanism requires further validation with real-world test data in multiple use cases. Requirements of maximum downtime vary and require case-by-case examination. The parameters of simulation are ad hoc, and not based on the real-world data. Penalties of managed standby is context-dependent and requires further consideration at deployment. Software-managed fault tolerance of IoT devices is a relatively new field and requires future evaluation. Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 24 / 26
  • 25.
    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conclusion For lightweight edge,it is important to deal with device failures rather than management of complicated computing resources with off-loading. The author defines the binary-level stand-by management is a part of task migration in lightweight edge computing. The author proposes a managed standby mechanism to make hybrid use of multiple standby mechanisms to dynamically adapt the device management. It facilitates the use of accumulated fault history data to provide proactive management of devices. The author performs a preliminary simulation to evaluate the advantages of managed standby with combined cold standby and hot standby modes. The simulation results show the managed standby method is promising considering the hybrid characteristics of cold-standby and hot-standby. This is an encouraging result for future exploration of proactive managed standby in smart city services. The future research include data-mining-based proactive management and deep learning of long-term fault characteristics using aggregated use of IoT maintenance history data. Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 25 / 26
  • 26.
    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Thank You forYour Attention! Questions? Toshihiko Yamakami (ACCESS Confidential)Device Stand-by Management Scheme of IoT: A Framework for Dealing with Real-world D2018/07 26 / 26