SaaS 傅汝緯 李碩元 林子驥 1

What is SaaS?  Definition :Software as a service  a software delivery model in which software and associated data are centrally hosted on the cloud 傅汝緯 李碩元 林子驥 2

How SaaS works? Tradition  Company need to buy the software (to maintain,to renew)  Cost more  Acceptance of risk SaaS  Company doesn’t need to buy the software but rent the software  To renew and to maintain the software is the duty of host  Use internet to achieve 傅汝緯 李碩元 林子驥 3

History of SaaS  1960s- An idea of SaaS has turned up -- there are some different between the concept of SaaS we know today 1990s- The expansion of the Internet during the 1990s brought about a new class of centralized computing -- Goal: reducing costs recently- SaaS become a new popular style for company to work Advantage: reduce costs Risk : data’s secret 傅汝緯 李碩元 林子驥 4

Challenge in Taiwan  The chance is huge but the challenge is huge too  1. Make or change the service according to the buyer's or user's needs   2. Stability of SaaS system   3. Function   4. Data secrete 傅汝緯 李碩元 林子驥 5

Examples of SaaS  Many companies were customers of modern SaaS system  Big software providers tend to connect their products with SaaS 傅汝緯 李碩元 林子驥 6

 Companies subscribed to Google Apps have access to it’s mail system and use it as their internal system without having to buy and implement an independent system within their company. Google Apps for business 傅汝緯 李碩元 林子驥 7

Google Apps for business  Google provides high level SLA for companies’ need of reliability and manageability. 傅汝緯 李碩元 林子驥 8

Chunghwa telecom - SaaS 雲  Chunghwa telecom provide several kinds of SaaS service for different kinds of demands, such as storage management or enterprise resource management 傅汝緯 李碩元 林子驥 9

Chunghwa telecom - SaaS 雲  Companies like 丐幫滷味 are subscribers to one of it’s services, which provides them an easy way to track each store’s selling details. 傅汝緯 李碩元 林子驥 10

Adobe Creative Cloud  Started in 2012, Adobe makes their flagship product, the Adobe Creative Suite, online available. 傅汝緯 李碩元 林子驥 11

Adobe Creative Cloud  All of your work can also be synced to your personal space on the cloud, so they make it possible for you to link all your work from different devices and different software. 傅汝緯 李碩元 林子驥 12

NEC’s C&C cloud  NEC provide a Managed Desktop service for companies to reduce the cost of hardware and software. 傅汝緯 李碩元 林子驥 13

Microsoft SkyDrive  SkyDrive is the online storage service provided by Microsoft  Most of the Microsoft product can be connected to the SkyDrive via a Windows live account 傅汝緯 李碩元 林子驥 14

Microsoft SkyDrive - Office web apps  With the office web apps, we can view and edit common Windows office file using simply your browser, connecting to the SkyDrive allows multiple user to simultaneously interact with the file. 傅汝緯 李碩元 林子驥 15

Microsoft SkyDrive  SkyDrive is integrated with Outlook so user could store the file in the mail on SkyDrive, users using web apps could also edit the file save and directly reply  Files on the SkyDrive could also be shared on the social network once the account is integrated 傅汝緯 李碩元 林子驥 16

Google Drive  Problem: storage network throughput  Cloud DFS: parallel read and write 傅汝緯 李碩元 林子驥 17

Google Drive  Google File System(GFS)  BigTable 傅汝緯 李碩元 林子驥 18

Google File System(GFS)  Proprietary DFS, efficient, reliable access to data using large clusters of commodity hardware  Producer-consumer queue  Need to support atomicity of data 傅汝緯 李碩元 林子驥 19

Google File System(GFS) 傅汝緯 李碩元 林子驥 20

Google File System(GFS)  Master: uses an in-memory index to track the names of data files and the location of their chunks  Chunk Servers: store chunks, assigned label, mapping files to chunk  Chunk replicates itself at least 3 times 傅汝緯 李碩元 林子驥 21

BigTable  Compressed, high performance, proprietary data storage system  Table-based data store, based on GFS  Mostly write once  Key-value mapping, 3dimensions- row key, column key, timestamp 傅汝緯 李碩元 林子驥 22

BigTable  Master server: allocate tablet to tablet server, monitor tablet server(ie. append and delete)  Tablet server: read and write to tablets, add and delete tablets depend on loading, doesn’t store data, instead, a bridge from Bigtable to GFS 傅汝緯 李碩元 林子驥 23

BigTable 傅汝緯 李碩元 林子驥 24

BigTable  Chubby file: location of root tablet  Root tablet: location of other tablets, assure the depth of tree unchanged 傅汝緯 李碩元 林子驥 25

BigTable and GFS  Only GFS know the real location of data, tablet server get all SSTable of tablets, tablet server know where to find data in SSTable by index. Then GFS read SSTable, SSTable may distribute in many chunk servers  SSTable: Sorted String Table 傅汝緯 李碩元 林子驥 26

Amazon Simple Storage Service(S3)  More general purpose data access, ie. Transaction system  Need more granular and dynamic access to data, more random access to smaller components(less than 1 MB)  Always writeable, highly available for data input  Like P2P  Consistent hashing 傅汝緯 李碩元 林子驥 27

Consistent hashing  When hash table resized and consistent hashing is used, only K/n keys need to be remapped on average  Monotonicity: if new key allocate to hash table, then hash table can assure all keys are mapping to new table  Balance 傅汝緯 李碩元 林子驥 28

Consistent hashing 傅汝緯 李碩元 林子驥 29

Consistent hashing 傅汝緯 李碩元 林子驥 30

Consistent hashing 傅汝緯 李碩元 林子驥 31

Conclusion  Define  History  Application  Microsoft Skydrive  Google Drive  Amazon S3 32

Thank you for listening 33