Presentation about the interaction among Cloud Computing and Mobile Device.

1. Mobile Cloud and a particular
framework for intelligent
local storage
Seminario di Sistemi Middleware A.A.2014/2015
Andrea Sghedoni

2. ● Interaction between Mobile Devices and Cloud
● New Era of computing
● LBS (Location Based Services)
Introduction
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3. ● Network Connection - TCP - 3G,4G
● Context Awareness - Sensors
- few user input
- automatic configuration
- intelligent output
● Limited processing capability
● Limited storage capability
Mobile Clients - Features
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4. ● Storage off-device
- devices have limited storage for SO, app, picture,
video, multimedia
- sharing data with other applications
- Trade-off between packets size and
requirement/network bandwith
- Local or Cloud storage? → WhereStore
- latency factors(Connection, transfer time,..)
Interactions with cloud(1)
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5. ● Processing off-device
- complex and intensive tasks - “black box”
- push technology
- asynchronous response
- device can process other tasks while wait
response from cloud server
- user wait time
- Amazon(EC2, EMR), Google, FlexiScale
Interactions with cloud(2)
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6. ● Study of social behavior - Activity context
● Weather app, navigator, BlaBlaCar,
traffic, integration with
bluetooth/beacons in a market
● Social network app, Restaurant reviews,
Meeting on LBS
Application and Social Contexts
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7. ● OpenID
- OpenID Provider keeps your password in a secure way
- Provider tells the websites/resources you’re visting that you are
who you say you are
● OpenAuth
- token based
- easy to invoke
- limited services - server side
Cloud security
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8. ● Different viewpoint from SOAP ws
● Perfect for integration between cloud and mobile
devices
● Aspects:
- Stateless
- URL Based
- Response HTTP-based
- Easy invocation method
RESTful Web Services (1)
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9. ● Response minimal and discrete
● HTTP standard
● REST responses very easy to understand and use it
● Rest request
- HTTP verbs (GET,POST,HEAD,PUT,DELETE) - CRUD
operations
● Event-driven-model for XML response
- DOM more memory usage and processing
RESTful Web Services (2)
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10. ● Framework for location-based data store in mobile
and cloud environments
● Users use a LBS mobile app in a particular location
(different from desktop app)
● Main goals of WhereStore:
- predict future smartphone location
- what data replicate in local device storage
- what data store in cloud
- data available in periods of no connectivity
WhereStore
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11. ● In many app, presence of data is a big
plus when there is no connection
- Web apps
- Media Content
- Live Applications
Example Applications
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12. ● Unused space on device for cache data
● What data to replicate at a given
time/location (no user input -
automatism)
● What data provide in the future
● Determine the optimal moment to
interact with cloud (home/Wifi)
Challenges
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13. ● Synchronization between different node
● Collection contains items (data + metadata)
● Replica → local subset or entire collection
● Filter → particular subset of a collection that
should be in a replica
● Each replica keeps data that match its filter
● Version of the items must be the same in all
replica
Replication System
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14. ● GPS sensor
● Monitoring of device location
● History → prediction of future location
● Difference between GPS measurements (morning/afternoon,
weekend/weekday, feast day/ common day ...)
● WhereStore creates and update filters
continuosly where:
- (l1
,l2
,...,ln
) → future locations
- (p1
,p2
,...,pn
) → probability
Location Prediction
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15. ● Items → piece of data with a particular priority
● Groups → set of items
● Regions → geographical area
Data types
work home shopping
books reviewsdocument movies
Regions
Groups
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16. Sync with Cloud
● App receives all the items that match with its filters, in a
precise moment
● Problem when smartphone storage capacity is not enough
for all replica items:
- for each item, cloud site compute a rank:
cj
= pi
* kj
where pi
→ probability of filter
kj
→ priority of item
● Only the top n items are send (n → capacity of device
storage), the others remain in cloud
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17. ● Cloud and RESTful WS provide solutions to
limited mobile capability
● Reducing of user input
● WhereStore, in particular, provide a set of
guideline for intelligent local storage and
prediction
Conclusions
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18. ● http://openidexplained.com/, description of OpenID
● http://hueniverse.com/oauth/, description of OpenAuth
● J.H.Christensen,“Using RESTful Web-Services and Cloud
Computing to Create Next Generation Mobile
Applications”, Orlando, Florida, Oct. 2009
● P.Stuedi, I.Mohomed, D.Terry, “WhereStore:Location-
based Data Storage for Mobile Devices Interacting with
the Cloud”, San Francisco, USA, June 2010
Bibliography
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