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| Date post: | 16-Jul-2015 |
| Category: |
Software |
| Upload: | doron-rosenstock |
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What is Wix? What is WixStores?
AgendaPart I
Overview of old system
Problems with the old system
Refactoring vs rewriting
Part II
Problems and solutions
Part III
Lessons learned
3
PART I Wix eCommerce
aka the “old system”
Architecture One monolithic server
Magento as a base
Written in PHP
MySql DB
Redis Cache
Some Numbers~1M stores
Over 5M http requests per day
Average response time of ~300 ms
2 data centers + 1 cloud (AWS)
Couple of seconds for store provision
The GoodStable system
Mature product
Lots of satisfied customers
Domain knowledge
Sounds good right?
?
MONOLITHSERVER CAN’T SCALE
LOW DEVVELOCITY
DEADTECHNOLOGY
Rewriting?Refactoring?
Pros
Will continue to deliver
Only critical sections fixed
Cons
Stuck with dead tech
Still different stack than Wix
Rewriting?
Refactoring?
Pros
If done correctly, solves old
system’s problems
Cons
Product freeze for 6 months
Might fail
Pros
Will continue to deliver
Only critical sections fixed
Cons
Stuck with dead tech
Still different stack than Wix
Rewriting?Refactoring?
PART II
aka the “new system”
The Problem: Monolithic Server
What’s the problem with Mono-server?One server to rule them all - single point of failure
Dependency between unrelated features
Need to deploy the entire system each time
What’s the problem with Mono-server?One server to rule them all - single point of failure
Dependency between unrelated features
Need to deploy the entire system each time
Monolithic Server
Micro-servicesEach microservice is relatively small
Each service can be deployed
independently of other services
Easier to scale development
Improved fault isolation
Each service can be developed and
deployed independently
Eliminates any long-term commitment
to a technology stack
Did we solve our problems?
Did we solve our problems?One server to rule them all - single point of failure
Dependency between unrelated features
Need to deploy the entire system each time
Did we solve our problems?One server to rule them all - single point of failure
Dependency between unrelated features
Need to deploy the entire system each time
Lessons Learned about Micro-ServicesError handling and log tracing in the cluster
Synced micro-services (WIP)
Configuration of micro-services (WIP)
Backward and forward compatibility design
Backward and forward compatibility
Service1 V1 Service2 V1
Backward and forward compatibility
Service1 V1 Service2 V1PRODUCT
Backward and forward compatibility
Service1 V1 Service2 V1PRODUCT
Service1 V2
Backward and forward compatibility
Service1 V1 Service2 V1PRODUCT
Service1 V2
PRODUCT
Backward and forward compatibility
Service2 V1
Service1 V2
PRODUCT
Backward and forward compatibility
Service2 V1
Service1 V2
PRODUCT
Service2 V2
PRODUCT’
Backward and forward compatibility
Service2 V1
Service1 V2
PRODUCT
Service2 V2
PRODUCT’
Backward and forward compatibility
Service1 V2 Service2 V2
Backward and forward compatibility
Service1 V1 Service2 V1
Backward and forward compatibility
Service1 V1 Service2 V1PRODUCT
Backward and forward compatibility
Service1 V1 Service2 V1PRODUCT
Service1 V2
Backward and forward compatibility
Service1 V1 Service2 V1PRODUCT
Service1 V2
PRODUCT
Backward and forward compatibility
Service1 V1 Service2 V1PRODUCT
Service1 V2
PRODUCT
Service2 V2
PRODUCT’
Backward and forward compatibility
Service1 V1 Service2 V1PRODUCT
Service1 V2
PRODUCT
Service2 V2
The Problem: Dev Velocity
Web App DBClient
Traditional CRUD
Web App DBClient
Traditional CRUD
upadteProductPRODUCT
Web App DBClient
Traditional CRUD
upadteProductPRODUCT
Web App DBClient
Traditional CRUD
getProductPRODUCT
Web App DBClient
Traditional CRUD
getProductPRODUCT
someCommand
Event Sourcing
Web App DBClient
COMMAND
someCommand
Event Sourcing
Command = “Change product X price to 3$“
Web App DBClient
COMMAND
someCommand
Event Sourcing
Command = “Change product X price to 3$“
Web App DBClient
COMMAND
someCommand
Event Sourcing
Command = “Change product X price to 3$“
Web App DBClient
COMMANDEVENT
event = “Product X price was changed to 3$“
someCommand
Event Sourcing
Command = “Change product X price to 3$“
Web App DBClient
EVENT
event = “Product X price was changed to 3$“
Event Sourcing
Web App DBClient
EVENT
EVENT
EVENT
getProduct
Event Sourcing
Web App DBClient
EVENT
EVENT
EVENT
getProduct
Event Sourcing
Web App DBClient
EVENTEVENTEVENT
getProduct
Event Sourcing
Web App DBClient
VIEW
getProduct
Event Sourcing
Web App DBClient
VIEW
Event Sourcing @ WixStoresFlexible
Immutable
Stateless
DB view
Lessons Learned about Event SourcingParadigm shifts - convincing the team…
Code complexity
Invest time in your framework - it will pay up
Solves backward and forward compatibly problem
DB size - space problem?
getProduct
Web App DBClient
EVENT
EVENT
EVENT
Web App
Events DB
Client
EVENT
EVENT
EVENT
getProduct
Web App
Events DB
Client
EVENT
EVENT
EVENT
getProduct
Web App
Events DB
Client
EVENTEVENTEVENT
getProduct
Web App
Events DB
Client
VIEWVIEW
getProduct
Web App
Events DB
Client
VIEW
SnapShots
VIEW
getProduct
Web App
Events DB
Client
VIEW
SnapShots
VIEW
Command Query Responsibility Segregation
@WixStoresSLA concerns:
Strong consistency vs Eventual consistency Viewer vs Editor
Lessons Learned about CQRSAgain - Code complexity
Self-healing
DevOps - two DB’s (Mysql + Mongo)
Performance
So… When should we stop and think?
CQRS CUTTING EDGE TECHNOLOGY
!
MICRO-SERVICES EVENT-SOURCED
LOW DEV VELOCITY
DEAD TECHNOLOGY
MONOLITH SERVER CAN’T SCALE
?
CQRS CUTTING EDGE TECHNOLOGY
!
MICRO-SERVICES EVENT-SOURCED
LOW DEV VELOCITY
DEAD TECHNOLOGY
MONOLITH SERVER CAN’T SCALE
?
Extra ReadingMicro-Services:
http://www.slideshare.net/aviranwix/scaling-wix-with-microservices-architecture
http://martinfowler.com/articles/microservices.html
CQRS: http://www.udidahan.com/2009/12/09/clarified-cqrs/
Event Sourcing: http://martinfowler.com/eaaDev/EventSourcing.html
http://blog.confluent.io/2015/01/29/making-sense-of-stream-processing/
http://esrad.org/
Questions?
il.linkedin.com/in/dorosen
http://engineering.wix.com
