Lucio Agostinho, Leonardo Olivi, Guiherme Feliciano, Fernando Paolieri, Diego Rodrigues,
Eleri Cardozo
School of Electrical Engineering
State University of Campinas
Campinas, Brazil
Eliane Guimaraes
Information Technology Center Renato Archer
Campinas, Brazil

 Introduction
 REALabs Platform
 Project Goal
 A Cloud Computing Environment
 Workflow Management System
 Implementation
 Evaluation

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The motivation for networked robotics is the availability of network technologies that allow robots to take part of comprehensive networking environments aggregating
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 processors, environmental sensors, mobile and stationary robots, wireless gadgets, other networked devices.
REALabs is a platform for networked robotics developed by the authors and reported in [1].
Its architecture has four main software packages as shown in Fig 1.

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The Embedded package consists of HTTP microservers able to run on the robots’ onboard processors with limited processing power
The Protocol Handler package intercepts all HTTP requests targeted to the robots and performs functions
 i.e security checks, HTTP proxying, and network address translations

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The Front-end package offers APIs (Application
Programming Interfaces) and Web components for manipulating the robots
The Management package offers a wide range of services related to users, resources, domains and federations.
 Also provides security

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REALabs is primarily used in Web Labs over the internet
Robotic applications may be time sensitive and may be inhibited by:
 Slow internet connections and the delay HTTP inspections introduce
 The processing power of the user for CPU intensive algorithms such as those based on computer vision and computational intelligence techniques.
In order to avoid the delays introduced by the slow internet connections and by the user’s computer limitations, we developed an environment where the user’s applications run on servers directly connected to the resources manipulated by the application.
 This environment is developed using virtualization in a cloud environment

 Our main focus in this work is to describe our architecture to perform robotic experiments in clouds.
 As an additional contribution, our approach extends the functionalities of Java Commodity
Grid (CoG) Kit Karajan
 We use this workflow tool as a Web workflow to schedule and map tasks according to QoS features.

 Introduction
 REALabs Platform
 Project Goal
 A Cloud Computing Environment
 Workflow Management System
 Implementation
 Evaluation

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In the case of REALabs, virtualization helps to bring the applications close to the robots they operate to reduce network delays and provide ample processing power
A user can own his/her own VMs with the proper
OS plus the network robotics software necessary for developing and running the applications
 Architecture must be designed to offer a virtualized environment where the distributed robotic applications run as opposed to overriding system software.

 REALcloud offers the REALabs platform as a service in a private (and small) cloud computing infrastructure.
 Both the client and server side are deployed inside VMs
 Server Side – Management and Protocol Handler packages
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 Virtualization favors software distribution to the members of a federation.
Client Side – Front End package
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User’s applications running inside VMs access the robotic resources with low delay and appropriate computing power

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In order to speed up interaction with robotic resources, applications running inside VMs access the robotic resources without HTTP inspection by the Protocol Handler package.
The REALcloud environment is built around two Web services:
1.
2.
VM management service : allows users and administrators to manage VMs.
Session validation service : allows applications running on VMs to access the robotic resources

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The SVS assigns VM privileges to users holding valid access sessions.
 Same protection as the Protocol Handler package (still needed for accessing outside networks)
As users create sessions, they register session IDs on a Web interface provided by the SVS
The SVS then queries the REALabs access service to check if the session ID is valid
 If the ID is valid, the SVS:
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 increases the resources for that VM and configures the VM host’s firewall to open the resource’s access for the traffic orginating at the VM
The SVS also handles reclaiming resources as sessions terminate and re-enabling firewalls

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REALcloud uses the IaaS model for users that wish to install and operate any other robotic software
The REALabs Embedded package is not virtualized as it runs on on-board processors without virtualization capabilities
With IaaS users can operate directly over the robotic framework installed on the robot without the need of the
Embedded package.

 Introduction
 REALabs Platform
 Project Goal
 A Cloud Computing Environment
 Workflow Management System
 Implementation
 Evaluation

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The Workflow Management System architecture was a concept in layered design patterns, in which services are grouped in layers, and the lower management layers provide services to higher management layers.
 Was developed to attend to the scheduling requirements of distributed services for several VMs within this specific cloud domain
The infrastructure maintains QoS dependencies to cloud services by submitting tasks in XML documents along with the presented workflow language.
Each task incorporates optional QoS arguments that are mapped to classes of constraints
Each task is defined in an XML namespace that admits other customized tasks
 Global QoS constraints are defined as tasks in the namespace
 Local QoS constraints overwrite global values when specified
Each VM uses an extended OVF (Open Virtualization Format) to dynamically track the many parameters of the current state

 Workflow layers include:
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Globus Toolkit (GT) – provides Grid services at the Grid middleware layer known as Simple Interface with Globus (SIG)
Manager Schema Layer – queries Web Service properties such as bandwidth, latency threshold, CPU usage, free memory, etc.
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SLA (Service Level Agreement) Manager Layer – specifies the minimum and maximum thresholds for the task and the policies applied when the contract is violated
Interceptor of QoS Layer – efficiently performs dynamic discover process and maintains services querying in the platform catalog
SIG Scheduler Layer – selects the available virtual hosts, keeping the previous service’s properties.
Workflow Engine Layer – holds monitoring services that periodically inform the higher layers when SLA contracts are violated or provisioned
QoS scenarios occur.

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The scheduling process is done using a divide-andconquer technique:
Dynamic discovery services recover available VMs for tasks with QoS requirements through the VM Manager Service
Mapping Services match VMs and QoS requirements
Planning Services evaluate correspondences in a rank matrix where higher values indicate better QoS matching
SLA specifies thresholds for the task querying the properties from the VM Manager Service
–
Execution Services in Workflow Engine accomplish the tasks with run-time monitoring
Rescheduling is done when the SLA values are under-previsioned

 Introduction
 REALabs Platform
 Project Goal
 A Cloud Computing Environment
 Workflow Management System
 Implementation
 Evaluation

 In order to implement the REALcloud cloud computing environment, we started with the selection of the virtualization solutions
 XEN Cloud Platform (XCP): native hypervisor
 VirtualBox: hosted hypervisor
 KVM: hosted hypervisor
 Linux Containers (LXC): OS level virtualization
 NOTE: a hypervisor is another name for a virtual machine manager

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These four virtualization solutions were evaluated in terms of the time it takes to perform three separate operations
1.
2.
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The operations given are the same criteria as the
REALabs report:
Set a speed to the robot
Read the robot’s sixteen sonars
Acquire a 320x240 picture from the robot’s onboard camera
Operations were performed 100 times each and results recorded
Results include Mean, standard deviation (SD) with confidence intervals (CI) of 95%.

Op1
LXC
Op2 Op3
• Minimum value
•
2nd lowest value
Op1
Xen (XCP)
Op2 Op3
2,774 5,919 33,471 3,110 5,739 34,330 Mean
SD
CI
801
157
1,143
224
3,826
750
1,204
236
1,169
229
7,255
1,422
Op1
3,142
KVM
Op2
7,081
Op3
32,896
Op1
4,205
VirtualBox
Op2 Op3
8,773 38,593 Mean
SD
CI
1,353
265
3,182
624
9,518
1,865
1,009
198
1,931
378
8,471
1,660

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As expected, virtualization at the operating system level performed slightly better, followed by virtualization employing a native hypervisor
The choice of virtualization solutions affects the implementation of the VM management service as this service must interact with the interface provided by the chosen solution
Initially we implemented the VM management service for
VirtualBox because it is the only multiplatform solution
 Also VirtualBox doesn’t require a restart to alter CPU and memory assignment

 The VM management and session validation services are implemented as Java servlets inside the Apache Tomcat application server
 REALcloud Web UI is presented in Fig. 4
 The session validation service relies on iptables
[11], the Linux native firewall, for installing and dropping packet filters necessary for the VMs to access the robotic resources

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Upper part – inteface to the session validation service
Lower part – VM management service interface
 Allows users to start, stop, and check the status of their own
VMs
Administrators can create, configure, remove, and assign
VMs to users.

 Introduction
 REALabs Platform
 Project Goal
 A Cloud Computing Environment
 Workflow Management System
 Implementation
 Evaluation

 This experiment uses the SIGFlow workflow [2] to perform the robot navigation, and includes two tasks, respectively:
 Line detection (DexFaiza) and
 Fuzzy managing (fuzzyControl)
 Illustrated by figures 5 and 6.
 Both tasks are distributed the cloud environment

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Virtualization technologies can bring many advantages to networked robotics environments.
We presented a cloud computing environment that offers a networked robotics platform as a service with strong advantages in performance without compromising security
With virtualization and cloud computing, all the resources the robotics applications need can be supplied by the domain operating the robotic equipments.

[1] E. Cardozo, E. Guimar˜aes, L. Rocha, R. Souza, F. Paolieri and F. Pinho, “A Platform for Networked Robotics”, IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), Taipei, Taiwan, 2010.
[2] Agostinho, L. R., Souza, R. S., Paolieri, F., Olivi, L. R., Feliciano, G., Pinho, F.,
Teixeira, F., Rodrigues, D., Guimar˜aes, E. G., Cardozo, E.“Advances in Educational
Robotics in Cloud with Qualitative Scheduling in Workflows”. In: Computer
Communications and Networks. Book Chapter. University of Derby. Springer, 2011.
[3] The Globus Project. http://www.globus.org. Accessed August 2011.
[4] E. Cardozo, E. Guimar˜aes, F. Paolieri and V. Pinto,”REALabs-BOT: a WebLab in
Mobile Robotics Over High Speed Networks”, First IFAC Workshop on Networked
Robotics, Golden, USA, 2009.
[5] S. Nanda and T. Chiueh, “A Survey on Virtualization Technologies”, www.ecsl.cs.sunysb.edu/tr/TR179 . pdf, March 2011.
[6] J. Rittinghouse and J. Ransome, Cloud Computing: Implementation, Management, and Security, CRC Press, 2009.
[7] Xen Cloud Platform, www.xen.org/products/cloudxen . html, March 2011.
[8] VirtualBox Web site, www.virtualbox.org, March 2011.

[9] KVM Web site, http://www.linux-kvm.org, March 2011.
[10] LXC Linux Containers project, http://lxc.sourceforge.net/ , March
2011.
[11] Netfilter/Iptables project, http://www.netfilter.org/ , March 2011.
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[13] W. Pedrycz and F. Gomide, Fuzzy Sytems Engineering: Toward
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[15] J. Yu and R. Buyya.“A Taxonomy of ScientificWorkflow Systems for
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[16] M. Inaba, “Remote-Beained Robots”, International Joint
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