adnan - communications in clouds

8/2/2019 Adnan - Communications in Clouds

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Communications in clouds

Adnan Faisal

[email protected]

13 March 2012

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Outline

Traffic in Data Centers

Traditional DC vs. Cloud DC

Volume, Type, Growth of Traffic

Cloud Services by Categories Communication obstacles in Clouds

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When we say Amazon has cloud, does it mean amazon has both traditional dc and cloud dc?

in other words, can a cloud contain traditional data center.


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Traffic in Data Centers

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Data Center Classification

Difference: in the levels of virtualization,

standardization, automation, and security.

Cloud data centers offer increased performance,

higher capacity, and greater ease of management

compared with traditional data centers.

2 kinds of Data Centers

Cloud Data Centers: deal with cloud traffic

Traditional Data Centers: deal with non-cloud traffic

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sure? I think cloud has less security.


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Workloads in Data Centers

The number of workloads per installed

traditional server will increase from 1.4 in2010 to 2.0 in 2015.

The number of workloads per installed cloudserver will increase from 3.5 in 2010 to 7.8 in

2015.

By 2014, more than 50 percent of allworkloads will be processed in the cloud.

Source: Cisco global cloud index (2010-2015), 2011

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what is meant by workload? application?


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Global Data Center Traffic Growth

Source: 6


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Traffic Classification by Destination

In 2010, 77 percent of traffic remains within the data center, andthis will decline only slightly to 76 percent by 2015.

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Why So Much Traffic Within DC?1. Functional separation ofApp Server and

Storage -> All backup traffic traverse DC

2. Functional separation ofApp Server andDatabase -> Generates traffic whenever an appreads from or writes to the central DB

3. Parallel processing -> divides tasks into multiple

smaller tasks and sends them to multipleservers, contributing to internal data centertraffic

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Any exception for video files? Video files require less/no database and

processing operation. Will increasing videofiles increase the ratio of DC-to-user traffic?

The present virtualization of data centers

offsets this trend. Virtualization of storage increases traffic

within the data center because virtualized

storage is no longer localto the server or toits rack.

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We need cloud edge for reducing this intra-cloud traffic.


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Transition of Workloads: Traditional DC -> Cloud DC

A workload can be defined as the amount of processing aserver undertakes to execute an application and support anumber of users interacting with the application. 10


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Cloud Data Center Traffic Growth

By 2015, more than one-third of all data center

traffic will be based in the cloud. 11


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Global cloud traffic by End-user:

Consumer vs. BusinessCAGR

2010-2015

Consumer 67%

Business 53%

115226

413

686

1005

1503

16 31 5279 109

139

0

200

400

600

800

1000

1200

1400

1600

2010 2011 2012 2013 2014 2015

Petaby

tesperYear

Consumer

Business

Consumer: Traffic originating with or destined for personal end-users

Business: Traffic originating with or destined for business end-users12

I guess end-users using business apps(such as ebay or amazon users) are

also counted as consumer.


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Cloud services by App Categories

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Cloud services App Categories1. Basic Cloud Apps: Text communication (e.g., email) ,

browsing, basic file sharing, social networking, basicvideo/audio streaming

2. Intermediate Cloud Apps: medium file sharing, IP

telephony, ERP/CRM, basic gaming, basic video chat,IP audio conference, Basic video conference, HD(720p or 1080p) video streaming

3. Advanced Cloud Apps: Advanced gaming / video chat/ file sharing, HD audio/video conferencing, UHD(4320p) video

14The distinctions are not quantified rather descriptive.All games do not require same response time, so classifying games to different category is not very easy.


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Requirements by App Categories

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SInce it is from cisco, I guess the values you see here are the one cisco thinks feasibile to achieve: Murray


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Communication Obstacles in Clouds

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Obstacle (1):

WAN Communication

Reduce the cost of WAN bandwidth

2/3 of the cost -> high-end routers 1/3 of the cost -> fiber

Researchers are exploring simpler routers built

from commodity components with centralizedcontrol.

Intra-cloud networking technology may be aperformance bottleneck as well.

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Dorina: Is there any alternative possible architecture?


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Cloud Communication Architecture

20 to 80 processing nodes on each rack

Top-of-rack switch

Router

1 GbE

10 GbE

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Dorina: Is there any alternative possible architecture?

Me: Yes, there is a paper related to Aneka cloud.


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Obstacle (1):

WAN Communication 1GbE in lower level of aggregation can be a

performance bottleneck when the inter-nodeprocessing pattern burst packets across theinterconnect (e.g., during the shuffle step of Mapand Reduce)

10 GbE in aggregation link is currently (2009) tooexpensive ($1000 for 10 GbE/server connection) todeploy for individual servers.

This cost was expected to drop to less than $200 in2010.

Lack of bandwidth is one reason why few scientistsuse Cloud Computing.

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Obstacle (2): Data Transfer Physical shipment of disk is better (fast, cost-

effective) when transferring large amount of data(e.g., Transferring 10TB of data from UC Berkeleyto Amazon in Seattle)

1 day vs 45 days

$400 vs $1500 Unused Cloud computing cycles can be used for

other purpose

Note: Garfinkel found that avg write bandwidthto Amazon S3 from 3 sites is between 5 to 18Mbits/second.

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they did not consider the ISP cost. Also, what if amazon charges a lot of money

to receive physical disk?


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Obstacle (3):

Performance loss due to VM Applications sharing a common I/O device, such

as NIC or disk, experience loss of performancedue to crosstalk effects or usable bandwidth.

By crosstalk, they mean the loss of performanceobserved in one VM because of sharing the NIC

with other VM In [3], the researchers examine the NIC sharing

effects across VMs on a Xen virtualized server

An alternate paradigm (e.g., logical partitioningof NIC, removing IDD etc.) was described whichincrease the as high as 60% in some case.

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Crosstalk is not a good word in this context. Crosstalk refers to overhearing which isnot the case here.

the perf gain should be same when there are 5 VM comparing to when 2 VM.

Morever, when there are 5 VM, the max increment of X can be five fold.

Murray: Why sharing IO device is only problem? How is this different than processor sharing?


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Conclusions Cloud traffic will keep increasing day by day

Intra-cloud traffic would dominate over inter-cloud traffic and cloud-to-end-user traffic

Different cloud applications have differentservice requirements

Obstacles: Data transfer, Communication cost,

VM crosstalk

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References1. Above the Clouds: A Berkeley View of Cloud

Computing, 20092. Cisco global cloud index (2010-2015), 2011

3. J. Lakshmi and S. K. Nandy, ModelingArchitecture-OS Interactions using LQN

Models, in the Proc. of the 10th International

Conference on the HPC Asia, Khaosiung,Taiwan, March 2-5, 2009

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Glossary Gigabyte (GB) = 109

Terabyte (TB) = 1012

Petabyte (PB) = 1015

Exabyte (EB) = 10

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Zettabyte (ZB) = 1021

CAGR = Compound annual growth rate

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adnan - communications in clouds

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