service-oriented architecture
TRANSCRIPT
Service-oriented architecture
@H2Russia internal workshop
Monolithic Rails applications
End user
Domain logic
Database
Issues monolithic applications
• Complexity
• Hard deploy
• Hard use new tools (DB, languages, etc.)
• Scale team size
• Changes are typically expensive
What is it SOA?
• A modular style to software development is based on the use of distributed, loosely coupled, replaceable components.
• The fundamental concept of an SOA is that each component of the system is broken up into network-accessible services, which are integrated to make a functioning application.
Rails application with multiple services
End user
High level domain logic
Service 1
Domain logic
Database
Service 2
Domain logic
Database
Service N
Domain logic
Database
Service-Oriented Design with Ruby
SOA advantages over monolithic application
• Isolation
• Robustness
• Scalability
• Agility
• Interoperability
• Reuse
Isolation
• Object-oriented design
• Business logic
• System Isolation
Robustness
• Implementation can be changed without the API consumer’s knowledge.
• Example: Changing libraries, database or even languages.
Scalability
• Easy to scale portions of application individually.
• Can be handled on a case-by-case instead of requiring optimization of a single database for all cases.
• Easier to scale team size.
Agility
• New services can be implemented outside the full architecture.
• Service interface should be versioned. “/api/v1/users/:id”
• Design includes the ability to run multiple versions of a service simultaneously. “/api/v1/users/:id” and “/api/v2/users/:id”
Interoperability
• Prevents being tied to a specific implementation.
• Services ease interoperation with internal and external systems and with systems written in languages other than Ruby.
Reuse
• Service-oriented design enables reuse of components across multiple applications or clients.
• If services are created for internal use, they can be exposed later to the public.
Converting to Services
• Partitioning on Iteration Speed
• Partitioning on Logical Function
• Partitioning on Read/Write Frequencies
• Partitioning on Join Frequency
What we need to learn
• RESTful-Oriented Architecture
• HTTP Methods
• HTTP Caching
• MIME types
• I/O, Threading, and Parallelism
• Amazon AWS
• Create clients
• Testing and Mocking Service Calls
• Load Balancing
• Security
• Web Hooks
• Chef
• Typhoeus
Load Balancing
• Weighted Balance
• Round-Robin
• Least-Connections
• URI-Based
• Priority
• Lowest Latency
Caching
• HTTP cache (cache-control, ETag, last-modified, expires)
• Memcached
• Squid and Varnish
Debug
• Efficiency 2.0 Ops Middleware - track distributed transactions across its Ruby-based service oriented architecture
• Monitoring tool.
Development
• Use stub mode in clients in development environment.
• Disable stub mode when develop service.
Tests
• Test client with service
• Test application with stubbed service
• Test the full stack
