This document outlines a top-down method for analyzing performance issues in a multi-tier architecture. It describes starting with the user scenario, measuring end-user response times, and setting a target response time. It provides an example infrastructure with user, client, server, and database tiers. The method involves understanding what each component requests from the next one to identify where a performance issue lies - whether with the user, client, server, or database. By drawing the full architecture map and working top-down, the specific source of a performance problem can be found.

1. How to analyze
a Performance issue

2. Purpose
The objective of this presentation is to illustrate the Top-
Down method to analyze a Performance issue on a
multi-tier infrastructure.

3. 3 elements to define
a Performance issue

4. 1 Scenario
Describe the step-by-step scenario
and the intention of the user

5. 1 Measure
Measure the end-user
response time

6. 1 Objective
Identify the reasonable target to reach
for the end-user response time

7. Understand
your architecture

8. Draw the map
of all the components
of your infrastructure

9. Example of a standard
multi-tier infrastructure

10. Example of a standard
multi-tier infrastructure
Banker
User
The first component is your user.
Don’t forget him!

11. Example of a standard
multi-tier infrastructure
Banker
User
Client

12. Example of a standard
multi-tier infrastructure
Banker
User
Client
Server

13. Example of a standard
multi-tier infrastructure
Banker
User
Client
Server
Database

14. The
Method
TOP
DOWN

15. Understand what
each component
asks to
the next one
Banker
User
Client
Server
Database

16. From the Top
To the Bottom
Banker
User
Client
Server
Database
Understand what
each component
asks to
the next one

17. What has been asked to the Client:
Retrieves all the employees names by alphabetic order for the whole company
Banker
User
Client

18. What has been asked to the Client:
Retrieves all the employees names by alphabetic order for the whole company
Banker
User
Client
Intention of the user:
I want to retrieve all the employees whose name is "Doe"

19. What has been asked to the Client:
Retrieves all the employees names by alphabetic order for the whole company
Banker
User
Client
Intention of the user:
I want to retrieve all the employees whose name is "Doe"
Issue
The user did not perform the appropriate query to the system
The bug is on the User side

20. Client
Server
What has been asked to the Server:
Retrieves all the employees names by alphabetic order for the whole company

21. Client
Server
What has been asked to the Server:
Retrieves all the employees names by alphabetic order for the whole company
Intention of the user:
I want to retrieve all the employees whose name is "Doe’’
The user expressed properly his query to the Client

22. Client
Server
What has been asked to the Server:
Retrieves all the employees names by alphabetic order for the whole company
Intention of the user:
I want to retrieve all the employees whose name is "Doe’’
The user expressed properly his query to the Client
Issue
The Client did not express properly the real query of the user
The bug is on the Client side

23. Server
Database
What has been asked to the Database:
Retrieves all the employees names by alphabetic order for the whole company

24. Server
Database
What has been asked to the Database:
Retrieves all the employees names by alphabetic order for the whole company
Intention of the user:
I want to retrieve all the employees whose name is "Doe"
The Client expressed properly his query to the Server

25. Server
Database
What has been asked to the Database:
Retrieves all the employees names by alphabetic order for the whole company
Intention of the user:
I want to retrieve all the employees whose name is "Doe"
The Client expressed properly his query
Issue
The Server did not express properly the query expressed by the Client
The bug is on the Server side

27. 3 key elements
1 Scenario
1 Measure
1 Objective

28. The Top-Down method
Draw the map
of all the components
of your infrastructure
Understand what each component
asks to the next one
Caller
Callee

29. To know more about me
Fabien RAYNAUD
www.FabienRaynaud.com
R&D Project Senior Manager at Dassault Systèmes
15 years of experience in software edition:
Development
Deployment
Quality
Performance
Scalability
September 2016