1. Amplifying feedback through Microservices and Containers
Meghashyam Varanasi - Associate Director
Cognizant Technology Solutions

2. 01 04 02 05 03 06 Introduction to the Topic
Functional / Non Functional Testing
Micro services Vs Services 02 05
QA benefits with Containers
Bottom up Testing Pyramid 03 06
Canary releases & role of container QA

3. Understanding the Topic
3 Principles of DevOps
Microservices
Containers
Traditional
Micro Services
One Block 1 2 3 4 5 6 8
Systems Thinking
Continual Experimentation
Feedback Amplification
Small
Autonomous
Choice of Technology
Service
Velocity
Variation
Visualization
Independent deployment

4. Services Vs. Micro services
Traditional Services
Micro Services
Autonomous
Decentralized
Independently Scalable
Technology Diversity
Loosely coupled
Characteristics
Shortcomings
Services are independent, cater to be new projects and language agnostic
Bits of code comprise services and are loosely packed
Intercom via API, specifically by a REST service
Service monitoring adds to overheads
Tracking service failures is a painstaking job
API calls are sometimes more of an overhead than the monolith intercommunication

5. Layers of Testing in Micro services
GUI Layer
E2E
Integrated
Systems Test
Verify that a system meets external requirements and achieves its goals, testing the entire system, from end to end.
Verify interactions at the boundary of an external service asserting that it meets the contract expected by a consuming service.
Contract Test
Limit the scope of the exercised software to a portion of the system under test, manipulating the system through internal code interfaces and using test doubles to isolate the code under test from other components.
Component Test
[Out Process & In Process]
Exercise the smallest pieces of testable software in the application to determine whether they behave as expected.
Unit Test

6. Microservice – Functional Testing at various layers
Unit Testing
Component Testing
Core unit level functionality testing
Test the lowest level of code
Full functionality testing of service
Similar to White box testing
Contract Testing
Integrated Systems Testing
Test the contracts the are agreed with other components/services
Interactions are verified at the boundary
Data flows, communication paths, Interactions among microservices
Integrations code, Protocol level issues
End to End Testing
Full-fledged testing by covering the overall application in test, infrastructure related items such as firewalls, proxies, load balancer

7. Microservice – Non Functional Testing
Performance Testing
Session Management & Cache Testing
Individual microservices need to be tested as per the desired levels
System wide performance testing
Session handling across the Microservices
Caching at the Microservice & system level
Fail Over and Recovery Testing
Load Balancing Testing
Build a strategy for fail over and recovery of individual services & test the same
Ensure that the containers are instantiated and load balanced as per the design (Prod)

8. Parallel Testing with Microservices
Build
Unit Test
Quality Scan
(Sonar)
Component
Test
Contract
Tests
Deploy to Dev
Contract
Tests
Deploy to Test
Contract
Tests
Service 4
Build
Unit Test
Quality Scan
(Sonar)
Component
Test
Contract
Tests
Deploy to Dev
Contract
Tests
Deploy to Test
Contract
Tests
Integrated
Systems
Test
Deploy to Prod
E2E Tests
Service 2
Build
Unit Test
Quality Scan
(Sonar)
Component
Test
Contract
Tests
Deploy to Dev
Contract
Tests
Deploy to Test
Contract
Tests
QG1: Unit Test, Code Coverage ,Static Analysis for critical and major violations
– Warning Threshold
QG2: Contract Test
QG3: Contract Test , Static Analysis for critical and major violations
– Error Threshold
QG4: Contract Test
QG5: Integration Execution status & Test cases in passed state
Any open Critical or major defects
QG6: E2E Execution status & Test cases in passed state
– Any open Critical or major defects
Service 3
Build
Unit Test
Quality Scan
(Sonar)
Component
Test
Contract
Tests
Deploy to Dev
Contract
Tests
Deploy to Test
Contract
Tests

9. What is a Container
A Technology Problem
A Shipping Industry Problem
A Shipping Industry Solution

10. Container/ Docker in Pictures – Virtual Machine Vs Container
Virtual Machines
Containers Vs
Containers are an abstraction at the app layer that packages code and dependencies together. 
Multiple containers can run on the same machine and share the OS kernel with other containers, each running as isolated processes in user space.
Containers take up less space than VMs (container images are typically tens of MBs in size), and start almost instantly.
Virtual machines (VMs) are an abstraction of physical hardware turning one server into many servers.
The hypervisor allows multiple VMs to run on a single machine.
Each VM includes a full copy of an operating system, one or more apps, necessary binaries and libraries - taking up tens of GBs. VMs can also be slow to boot.

11. QA Benefits of Containers
Ease of creating QA environments
Run more tests and Test faster`
Ability to create and terminate containers at will helps QA teams to bring up Test Environment with ease
Parallel tests can be executed on multiple containers in the test environment
Improved confidence in the production system
Run testing in environment with slight variation
Lesser environment/configuration mismatch issues
Improved confidence in the production system
Maintain & Test multiple environments with slight variation depending on the need

12. Canary Release – Container Advantages
Canary release is a technique to reduce the risk of introducing a new software version in production by slowly rolling out the change to a small subset of users before rolling it out to the entire infrastructure and making it available to everybody.
Canary Release
Blue Green Deployments
Canary Release - Fail Fast to Amplify Feedback
When running multiple versions of an application, one needs a quickly way to create copies of the application and make configuration changes. This is possible with containers, as they can be spun up in seconds, and abstract away the application from the operating system. Container is ideal for powering canary releases and testing them with confidence.

13. References & Appendix https://en.wikipedia.org/wiki/Microservices

14. Author Biography
Meghashyam Varanasi has about 15 years of experience in IT and ITes industry. He holds an MBA from IIM Ahmedabad & B.Tech Computer science degree. He is also AWS, PMP, ITIL certified besides few other technology and domain certifications. Over the years he has been working in solving various customer problems in the technology leadership space.

15. Q&A