Discuss Scalability, Resiliency, Responsiveness characteristics of Servlet Architecture vs Reactive Architecture Styles

1. Scalability,Resiliency,Responsiveness
Servlet vs Reactive

2. Services Setup: Scenario #1
Service A
Service B
Service C
Service C
Setup #1
Setup #2
Service A:
Spring MVC using
RESTTemplate
Service B:
Spring Reactor using
WebClient
Service C:
Spring Reactor
Takes 200ms to
respond to a HTTP
GET
GET /items/{category}
GET /items/{category}

3. Test Setup
Service A Service C
AWS
t2.micro t2.micro t2.micro
Service B Service C
AWS
t2.micro t2.micro t2.micro

4. Predict
Performance,
CPU, RAM

5. Expected Performance
Service B using Non-Blocking Architecture should outperform
Service A as the number of concurrent users increase.
Service B should have higher CPU Utilization.
Service B should have lower response time and higher throughput.

6. Code Walkhrough and
Performance Test
Execution

7. Performance
Test Results
Architecture Style Concurrent Users Execution Time
(seconds)
Ramp-Up
Time
(seconds)
Throughput (per
second)
Avg. Response
Time (ms)
A (MVC) 50 600 10 242 204
B (Reactive) 50 600 10 243 203
A (MVC) 100 600 10 476 208
B (Reactive) 100 600 10 472 210
A (MVC) 500 600 10 979 505
B (Reactive) 500 600 10 1430 345
A (MVC) 1000 600 10 965 1024
B (Reactive) 1000 600 10 1777 555
A (MVC) 1500 600 10 958 1546
B (Reactive) 1500 600 10 1755 815

8. Improve
Performance
of MVC
service

9. Services Setup: Scenario #2
Service A1
Service B
Service C
Service C
Setup #1
Setup #2
Service A1:
Spring MVC using
RESTTemplate
WebClient
Service B:
Spring Reactor using
WebClient
Service C:
Spring Reactor
Takes 200ms to
respond to a HTTP
GET
GET /items/{category}
GET /items/{category}

10. Expected Performance
Service A1 should outperform Service A. Service B should
outperform both Service A and Service A1.
Service A1 should have higher CPU Utilization than Service A.
Service A1 should have lower response time and higher throughput
compared to Service A.

11. Performance
Results
A R C H I T E C T U R E
S T Y L E
C O N C U R R E N T
U S E R S
E X E C U T I O N T I M E
( S E C O N D S )
R A M P - U P T I M E
( S E C O N D S )
T H R O U G H P U T
( P E R S E C O N D )
A V G .
R E S P O N S E
T I M E ( M S )
A (MVC-RT) 1000 600 10 965 1024
A1 (MVC-WC) 1000 600 10 1241 797
B (Reactive) 1000 600 10 1777 555
A (MVC-RT) 1500 600 10 958 1546
A1 (MVC-WC) 1500 600 10 1516 973
B (Reactive) 1500 600 10 1755 815

12. Responsive
Resilient

13. Simulate Failure and test
Responisveness and
Resiliency of Service A
and Service B

14. Reactive
Architecture
- Responsive
- Resilient
Service B on Reactive
Architecturewas Resilient and
Responsive even when
Dependent Services were down.
No need to implement
additional tooling like Circuit
Breakers.

15. Fast Producer,
Slow
Consumer

16. Fast Producer can take down the Slow
Consumer
Service A Service C
AWS
t2.micro t2.micro t2.micro
X msg/secY msg/sec
If Y < X then Service C can
eventuallycause Service A
to crash

17. Reactive Streams are
backpressure enabled
and thus the Consumer
would pull only so much
as it can process

18. Thank you!!
Code availableon Github:
https://github.com/vrawat79/itemReactiveMockedDB
https://github.com/vrawat79/itemMVCMockedDB
https://github.com/vrawat79/MockedDbService