1. 如何無痛上雲端?
以Elastic Beanstalk Java Container為例
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Study Hsueh <ph.study@gmail.com>
2013-11-07
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2. 上雲端
Deploy application to VPS (Virtual Private Server)
or
Cloud Web Application
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3. Cloud Web Application
Web Application is powered by cloud computing
Elasticity: 能隨時主動增加或刪減資源
Scalability: 資源的增減直接反應到負載上
Reliability: 應⽤用程式不會因為部分故障, 就無
法提供服務
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4. Cloud Web Application
Architecture for Web Application Hosting
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http://media.amazonwebservices.com/architecturecenter/AWS_ac_ra_web_01.pdf

5. Cloud Web Application
Build a cloud web application in AWS, you may need to know…
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Elastic Load Balancing (ELB)
Auto Scaling
Cloud Watch
Elastic Compute Cloud (EC2)
Deployment
Management
Monitoring
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Infrastructure

6. 有沒有簡單⼀一點的⽅方法上雲端?
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7. 有!
⽤用PaaS吧!
PaaS: Platform as a Service
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8. 可是聽說PaaS....
White List
Black Box
Platform Dependent Services/Libraries
Software Versions
…etc
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9. 試試Elastic Beanstalk吧:)
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10. Elastic Beanstalk (EB)
Elastic Beanstalk是架構在AWS infrastructure
上的PaaS服務, 使⽤用Elastic Beanstalk可以同
時具備控制底層IaaS的能⼒力與PaaS的便利
Elastic Beanstalk的縮寫是EB (不是EBS,
EBS是Elastic Block Store的縮寫)
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11. Elastic Beanstalk
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12. Concept(1)
Elastic Beanstalk
Application
Environment
URL(CNAME)
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13. Concept(2)
Applications
Environments
URL
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14. Supported Platforms
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15. Java Container
OS: x32/x64 Amazon Linux (2012.09)
Java: OpenJdk 1.6.0_24
Web Container: T
omcat 6.0.35 & 7.0.27
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16. Customization
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17. Elastic Beanstalk可以裝第三⽅方的程式嗎?
像是phantomjs, imagemagick…之類
或把T
omcat換成T
omEE?
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18. Customizing Environment
Elastic Beanstalk provides two mechanisms to
customize environment
Custom AMI
Configuration File (Oct 2. 2012)
including AWS resources (e.g. ElastiCache)
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19. Configuration File(1)
Configuration File in WAR file
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20. Configuration File(2)
Configuration File Example
YAML format
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21. Deployment
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22. AWS Management Console
Upload WAR file
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23. AWS T
oolkit for Eclipse
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24. Command-line interface
$ git init
# init git repository
$ eb init
# init EB Application Configuration
$ eb start
# start EB Environment
$ git add .
# track all files
$ git commit -m “Initial Commit” # commit
$ git aws.push
# push to EB
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25. Deploying with Zero Downtime
Swap Environments URLs (CNAMEs)
It usually takes 2-3 minutes to swap
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26. Management
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27. Application versions
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28. Monitoring
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29. Health Check
EC2 Instance
TCP:80 for nonlegacy containers
HTTP:80 for legacy containers
Application health check URL
HTTP 200 OK= Health
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30. Usage
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31. Processes
Use Monit to monitor processes
Apache HTTP Server
Apache T
omcat
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32. Pricing
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33. Pricing
Elastic Beanstalk is free, you only pay for the underlying
AWS resources
Single-instance T
ype
EC2 instance
Load-balancing, Autoscaling T
ype
EC2 instance(s)
Elastic Load Balancing
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34. 準備好上雲端了嗎?
Cloud Ready?
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35. 如果程式有⽤用到下列其中⼀一個...
HTTP Session
File System
User Data Storage
File Cache
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36. 對不起！還不能上雲端:-(
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37. HTTP Session Problem
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38. HTTP Session Problem(1)
Server#1
Server#2
Session
Session
ABAB
CDCD
table
table
User#1
User#2
JSESSIONID: CDCD
JSESSIONID: ABAB
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39. HTTP Session Problem(2)
Server#1
Server#2
Session
Session
table
table
ABAB
CDCD
Load Balancer
Invalid Session
uses Round Robin
for Server#2
redirect
User#1
User#2
JSESSIONID: CDCD
JSESSIONID: ABAB
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40. Solutions for HTTP Session
改程式的做法
Keep Stateless (use access token)
不改程式的做法
Session Persistence
Sticky Sessions (Not working for Auto Scaling)
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41. Sticky Sessions Problem(1)
Server#1
Server#2
Session
Session
ABAB
CDCD
table
table
Load Balancer
Server
Session
enables Sticky Sessions
Server#1
ABAB
Server#2
CDCD
User#1
User#2
JSESSIONID: CDCD
JSESSIONID: ABAB
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42. Sticky Sessions Problem(2)
Server#1
Server#2
Session
Scale in or
Server Failure
table
ABAB
Invalid Session
Server
Session
for Server#1
Server#1
ABAB
Server#2
CDCD
User#1
User#2
JSESSIONID: CDCD
JSESSIONID: ABAB
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43. Session Persistence
Shared Session
table
Server#1
ABAB
CDCD
User#1
Server#2
User#2
JSESSIONID: CDCD
JSESSIONID: ABAB
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44. Session Managers for T
omcat
PersistentManager (JDBC Based Store)
http://tomcat.apache.org/tomcat-7.0-doc/config/manager.html#Nested_Components
Memcached Session Manager
http://code.google.com/p/memcached-session-manager
Redis Session Manager
https://github.com/jcoleman/tomcat-redis-session-manager
Amazon DynamoDB Session Manager
https://github.com/aws/aws-dynamodb-session-tomcat/
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45. Session Managers for T
omcat
Q. 為什麼不使⽤用DeltaManager或
BackupManager呢? (in-memory-replication)
A. EC2不⽀支援multicast與boardcast (不完全⽀支
援)
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46. File System Problem
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47. User Data Storage Problem(1)
Server#1
Server#2
File#2
File#1
User#1
User#2
Upload File#1
Upload File#2
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48. Solutions for User Data Storage(1)
Use FS for User Data Storage
改程式的做法
透過AWS SDK把檔案的存取改到S3
不改程式的做法
⽤用S3FS或NFS
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49. 使⽤用S3FS需注意的地⽅方
流量
上傳: 檔案會先上傳⾄至Server, 在由Server寫⼊入S3
下載: 檔案需先由S3取出到Server, 在回傳給User
負載
無法降低Server負載
安全性
敏感的資料: 避免直接對外
⼀一般資料: 直接把網址對外, 可降低負載與下載流量
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50. Solutions for File Cache
Use FS for File Cache
改程式的做法
將file cache改存⾄至DB或Cache Clusters
不改程式的做法
?
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51. 可以⽤用S3FS做File Cache嗎?
S3不適合儲存File Cache
Latency
Read-After-Write Consistency
Eventually Consistency (US Standard
Region)
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52. Summary
Elastic Beanstalk is PaaS, but you retain full
control over the underlying infrastructure
Elastic Beanstalk is Free
For Scalability, you should pay attention to
HTTP Session
File System
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53. Thanks for your attention:)
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