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上雲端
Deploy application to VPS (Virtual Private Server)
Cloud Web Application
or
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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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Cloud Web Application
!4 http://media.amazonwebservices.com/architecturecenter/AWS_ac_ra_web_01.pdf
Architecture for Web Application Hosting
Cloud Web ApplicationBuild a cloud web application in AWS, you may need to know…
Elastic Load Balancing (ELB)
Auto Scaling
Cloud Watch
Elastic Compute Cloud (EC2)
Deployment
Management
Monitoring
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Infrastructure}
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有沒有簡單⼀一點的⽅方法上雲端?
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有! ⽤用PaaS吧!
PaaS: Platform as a Service
可是聽說PaaS....
White List
Black Box
Platform Dependent Services/Libraries
Software Versions
…etc
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試試Elastic Beanstalk吧:)
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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Elastic Beanstalk
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Elastic Beanstalk
Concept(1)
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Application
Environment
URL(CNAME)
Concept(2)
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Applications
Environments
URL
Supported Platforms
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Java Container
OS: x32/x64 Amazon Linux (2012.09)
Java: OpenJdk 1.6.0_24
Web Container: Tomcat 6.0.35 & 7.0.27
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Customization
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Elastic Beanstalk可以裝第三⽅方的程式嗎? 像是phantomjs, imagemagick…之類
或把Tomcat換成TomEE?
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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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Configuration File(1)Configuration File in WAR file
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Configuration File(2)
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Configuration File Example
YAML format
Deployment
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Upload WAR file
AWS Management Console
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AWS Toolkit for Eclipse
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$ 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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Command-line interface
Deploying with Zero Downtime
Swap Environments URLs (CNAMEs)
It usually takes 2-3 minutes to swap
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Management
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Application versions
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Monitoring
Health CheckEC2 Instance
TCP:80 for nonlegacy containers
HTTP:80 for legacy containers
Application health check URL
HTTP 200 OK= Health
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Usage
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ProcessesUse Monit to monitor processes
Apache HTTP Server
Apache Tomcat
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Pricing
PricingElastic Beanstalk is free, you only pay for the underlying AWS resources
Single-instance Type
EC2 instance
Load-balancing, Autoscaling Type
EC2 instance(s)
Elastic Load Balancing
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準備好上雲端了嗎? Cloud Ready?
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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對不起！還不能上雲端:-(
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HTTP Session Problem
HTTP Session Problem(1)
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Session table
ABAB
Session table
CDCD
JSESSIONID: CDCD JSESSIONID: ABAB
Server#1 Server#2
User#1 User#2
HTTP Session Problem(2)
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Session table
CDCD
JSESSIONID: ABAB
Server#2Session
table
ABAB
JSESSIONID: CDCD
Server#1
User#1 User#2
Invalid Session for Server#2
Load Balancer uses Round Robin
redirect
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
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(Not working for Auto Scaling)
Sticky Sessions Problem(1)
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Session table
ABAB
Session table
CDCD
JSESSIONID: CDCD JSESSIONID: ABAB
Server#1 Server#2
User#1 User#2
Server Session
Server#1 ABAB
Server#2 CDCD
Load Balancer enables Sticky Sessions
Server Session
Server#1 ABAB
Server#2 CDCD
Sticky Sessions Problem(2)
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Session table
ABAB
JSESSIONID: CDCD JSESSIONID: ABAB
Server#1 Server#2
User#1 User#2
Scale in or Server Failure
Invalid Session for Server#1
Session Persistence
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Shared Session table
ABAB
CDCD
JSESSIONID: CDCD JSESSIONID: ABAB
Server#1 Server#2
User#1 User#2
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Session Managers for Tomcat
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/
Session Managers for Tomcat
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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File System Problem
User Data Storage Problem(1)
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Server#1 Server#2
User#1 User#2
File#1
Upload File#1
File#2
Upload File#2
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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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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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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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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SummaryElastic 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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Thanks for your attention:)
