Presentation about software availability; by Resilience Design from the first days of project.

1. Availability
In the name of ALLAH
Software Availability, By
Reza Same'e
By
SOFTWARE DEVELOPER @ BISPHONE
At
ZCONF - 6th
Sep 2015 | Shahrivar 1394
< reza.samee@gmail.com >
Availability
Resiliency

2. Resiliency Availability ?
Available :
Present or Ready
for Immediate use
Available :

3. Resiliency Availability ?
As far as they ( USERS ) know, when the response time
exceeds their expectation,
the system is down.

4. Resiliency Availability ?
Available :
Ready for Immediate use
and React Quickly
Available :

5. Resiliency How to Measure ?
https://en.wikipedia.org/wiki/High_availability
Availability = MTTF / ( MTTF + MTTR )Availability = MTTF / ( MTTF + MTTR )
Mean Time To Failure = MTTF
Mean Time To Recovery = MTTR
MTTF ~= Uptime
MTTR ~= Downtime
Availability ( percent ) Downtime
99.9999999 “Nine Nine” Less than 32 ms in year
99.99999 “Seven Nine” About 3 sec in year
99.999 “Five Nine” About 5 min in year
99.9 "Three Nine" About 9 hours in year

6. Resiliency Why Matters ?
- Critical Systems ( Health-Care , … )
- Business
- Our Quality of Life (^_^)
398/Second
34.4 Millions Items
http://www.forbes.com/sites/ryanmac/2015/07/16/amazon-says-prime-day-was-huge-success-and-vows-to-repeat-it-despite-customer-criticism/
http://www.forbes.com/sites/ilyapozin/2013/10/17/industry-to-watch-in-2014-healthcare-tech/

7. Resiliency Problem ?
Failures Are Everywhere !Failures Are Everywhere !

8. Resiliency Solution ?
You Can't Prevent Failures
… then You Should Manage Them.
You Can't Prevent Failures
… then You Should Manage Them.
- ?
Reduce MTTRReduce MTTR
Availability = MTTF / ( MTTF + MTTR )

9. Resiliency Reactive Manifesto ?
Reactive Manifesto
Responsive
React To Users
Message Driven
Modules / Components Interaction
Resilient
React To Failures
Elastic
React To Load
Responsive
ElasticResilient
Message Driven
Reactive Manifesto
Goal
Principle
Principle
Method
http://www.reactivemanifesto.org/

10. Resiliency Reactive Manifesto and Availability ?
Available =
Responsive + Resilient
Availability
Depends On Resiliecy
Availability
Depends On Resiliecy
Availability
Depends On Resiliecy
Available =
Responsive + Resilient

11. Resiliency Resiliency
Resiliency means
React to Failures
A resilient system keeps processing transactions, even
when there are transient impulses, persistent stresses, or
component failures disrupting normal processing. This is
what most people mean when they just say stability.
Resiliency means
React to Failures

12. Resiliency Resiliency
Design For Resiliency in Real World

13. Resiliency Resiliency
Isolation
Communication
Failures
Isolation Over Functionality & Failures +
Abstraction Over Accessibility

14. Resiliency Isolation: Functionality, Resources & State
Functionality, Resources, State
Isolation
Single Responsibility -
Share Nothing -
Stateless -
Eventual Consistency & Idempotency -
… -

15. Resiliency Isolation: Functionality, Resources & State
BULK HEADBULK HEAD
Isolation &
Redundancy
Isolation Over Failure
+
Prevent Chain of
Failure
https://en.wikipedia.org/wiki/Compartment_(ship)

16. Resiliency Communication
Location TransparencyLocation Transparency
DNS, Load Balancers, Message Brokers
Face 2 Face vs. Phone/Email
"Where" != "Who"

17. Resiliency Communication
Avoid Call StackAvoid Call Stack

18. Resiliency Communication
Async – 1 : Event DrivenAsync – 1 : Event Driven
Concurrency isn't Easy !
Break Isolation (State,Resources-Context)
Isolation Over Failure
Lock-Free

19. Resiliency Communication
Async – 2 : Message DrivenAsync – 2 : Message Driven
The Big Idea is “Messaging” – Alan Kay
vs.

20. Resiliency Communication
Async – 2 : Message DrivenAsync – 2 : Message Driven
The Big Idea is “Messaging” – Alan Kay
Lock-free & Non-Blocking
Lead to Elasticity ( Scalability )
Throttelling
Location Transparency
Isolation Over Failure
Share Nothing & Bulk Head
Concurrency is Easy !
Very Flexible
*

21. Resiliency Communication
Avoid Unlimited Resources
Strict And Bug-Free API
Use Timeout
...
AND MORE …AND MORE …
Avoid Unlimited Resources
Strict And Bug-Free API
Use Timeout
...

22. Resiliency Failure
In Resilient System
Failures Are First-Class
In Resilient System
Failures Are First-Class
( Fault Tolerancy )

23. Resiliency Failure
Fail Fast : Immediate & Visible
before ... Desecrating State
& Being ZOMBIE :(
http://bond.trendolizer.com/2015/01/how-to-jump-out-of-a-moving-car-and-survive.html
Crash Safely
Fail Fast : Immediate & Visible

24. Resiliency Failure
http://bond.trendolizer.com/2015/01/how-to-jump-out-of-a-moving-car-and-survive.html
Circuit Breaker -
Strict API -
Avoid Default Values -
Timeout -
Shed Load -
… -
Fail Fast : Immediate & VisibleFail Fast : Immediate & Visible
Circuit Breaker -
Strict API -
Avoid Default Values -
Timeout -
Shed Load -
… -

25. Resiliency Failure
Ciruite BreakerCiruite Breaker
A little Fail-Fast
*

26. Resiliency Failure
SupervisorSupervisor
Supervise ME :)Supervise ME :)
Monitor
Restart
Stop
Escalate
Monitor
Restart
Stop
Escalate
http://www.topdreamer.com/funny-cute-baby-faces-photos/

27. Resiliency Failure
Error KernelError Kernel

28. Resiliency Failure
Error KernelError Kernel
FAILED

29. Resiliency Failure
Error KernelError Kernel
FAILED

30. Resiliency Failure
Error KernelError Kernel
RESTARTED

31. Resiliency Failure
Error KernelError Kernel
RESTARTED
One-For-One
All-For-One

32. Resiliency Failure
http://askatoddler.com/redundancy/
RedundancyRedundancy

33. Resiliency And More ...
Test
- Platform, Tools & Framework
- Pull The Plug
Test
http://blog.mmeconsulting.com/a-simple-but-costly-mistake/man-yanking-electrical-cord/

34. Resiliency And More ...
PlatformPlatform
- Experience
- Maturity & Tools
- Platform Dependent: GC , ...
*

35. Resiliency And More ...
UI & UX
- Hide Failures
- Consistency

36. Resiliency Summary
- Isolation is the first step of Resiliency
- Better Isolation By “Async" Communication
- Manage Failures by Fail-Fast and Supervisor
- Hide Failures in UI & UX

37. Resiliency GoodLuck (^_^)
Your Quality of life after release 1.0 depends on
choices you make long before that vital milestone.
People's Quality Of Life Depends On Our Choices
– Me :)

38. Resiliency GoodLuck (^_^)
- Question ?
- Thanks :)
Reza Same'e
SOFTWARE DEVELOPER @ BISPHONE
< reza.samee@gmail.com | http://samee.blog.ir | @reza_samee >
Interested In Scala, Functional and Reactive
We Are Hiring!
If You are interested in Scala / Java or Erlang,
Let we know: jobs@bisphone.com