Developing Cloud Computing Applications with Open Source Technologies

1
Developing Cloud Computing Applications with Open
Source Technologies

• Shlomo Swidler
• CTO co-Founder mydrifts.com
• 1 December 2008

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Agenda

• Open Source and Cloud Computing a great match!
• Challenges faced by developers in the cloud...
• ... and open source solutions

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• Marketing platform for indie music promotion
• Help indie musicians find fans among social
  network users
• Cloud-based, using open source solutions
• Professional Services and Consulting
• Cloud computing, scalable web applications

4
Open Source and Cloud Computing

• Same motivation low ongoing costs
• mydrifts.com chose Amazons EC2
• Rich set of complementary tools
• Many open source projects, too
• Freedom to choose OS, language, DB - the entire
  stack
• Choice of hardware

5
Challenges Faced by Developers in the Cloud
HOW?
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Developing Scalable Cloud Applications

• Optimize your database
• Use caching
• Use service pools

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Typical Application Architecture Three Tiers
Load Balancer
Client
Web Tier
Database Tier
BusinessLogic Tier
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Scaling the Database Tier Optimize Queries

• Optimize your database
• Know your queries
• Know your indexes
• De-normalize tables where needed
• Open-source (MySQL)
• Use the slow query log
• EXPLAIN SELECT is your friend
• MySQL has query analysis tools ()

Database Tier
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Scaling the Database Tier Cache

• Cache to reduce database hits
• Not just query results
• Objects, partially rendered pages, etc
• Open-source
• memcached

DB
Database Tier
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memcached

• Distributed in-memory cache
• Extremely low CPU usage
• Used by facebook, Wikipedia, Amazon, Yahoo, etc.
• Use leftover memory on a machine to serve as
  cache
• Great for cloud instances

memcached server A
memcached server B
DB
memcached server C
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Application with Scalable Database Tier
Load Balancer
Client
DB
cache
Database Tier
Web Tier
BusinessLogic Tier
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Anatomy of the Business Logic Tier

• Components have different resource usage
• Requests flow through different components
• Limited scaling granularity

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Scaling the Business Logic Tier Service Pools
Pool A
Pool B
Pool C
Pool D

• Separate homogeneous pools of instances
• Each pool of services is independently scalable

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Architecture of Service Pools
Status Logger
Msg Queue
Msg Queue
Pool Manager
Pool
status
status
Service
Service
Service
Ingestor
Message Queue
Message Queue
work request
input
input
output
Storage
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Scalable Business Logic Tier
Pool B
Pool A
Service
Service
Service B
Service
Service
Service A
DB
cache
Pool C
Service
Service
Pool D
Service C
Service
Service
Service D
Database Tier
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Open Source Service Pools on Amazon EC2

• Lifeguard (Java) http//code.google.com/p/li
  feguard see http//developer.amazonwebservic
  es.com/connect/entry.jspa?externalID915
• Kato (Ruby) http//rubyforge.org/projects/ka
  to/
• Implemented using boto (Python) see
  http//developer.amazonwebservices.com/connect/ent
  ry.jspa?externalID691

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Scalable Cloud Application Architecture
Load Balancer
Pool
Client
DB
cache
Pool
Database Tier
Web Tier
BusinessLogic Tier
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Q A
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Developing Cloud Computing Applications with Open
Source Technologies

• Thank you!

Shlomo Swidler shlomo.swidler_at_mydrifts.com