1. Performance Engineering Fundamentals
Practical Performance Analyst – 23rd June 2012
http://www.practicalperformanceanalyst.com

2. Agenda
What is Performance Engineering
Why is Performance Engineering Important
Performance Engineering Life Cycle
Holistic View of Performance
Activities involved in Performance Engineering
What does Performance mean to different stake holders
Roles performed by the Practical Performance Analyst
What is Proactive Performance Management
Cost of addressing Performance across the SDLC
Challenges in addressing Performance Engineering

3. What Is Performance Engineering
Definition - Performance Engineering (SPE) is a systematic and quantitative approach for the cost-effective development of software systems to meet stringent Non Functional Requirements (Performance - Capacity - Scalability - Availability - Reliability - etc).
Dr. Connie Smith in her book on Software Performance Engineering (URL - http://www.perfeng.com/) advocates that, Performance Engineering is a software-oriented approach, focused on optimal selection of application architecture, design, and implementation choices with the objective of meeting Non Functional Requirements.
Software Performance Engineering can also be defined functionally as the set of tasks or activities that need to be performed across the Software Development Life Cycle (SDLC) to meet the documented Non Functional Requirements.
Software Performance Engineering is often viewed as the art of building systems that meeting Non Functional requirements within the allocated time frame and budget constraints.

4. Why Is Performance Engineering Imp
Performance Engineering is important for the following reasons –
Determine End User Experience desired by customer for the applications being developed
Understand Non Functional Requirements for the applications
Determine Performance Targets for the Developers across the various different application tiers
Work proactively with Developers to ensure Performance Targets are addressed across the Build phase
Ensure that the application architecture chosen will allow you to meet the Non Functional Requirements
Determine the infrastructure capacity required to meet your Non Functional Requirements & IT SLA’s
Identify any major architectural or platform concerns early in the SDLC
Identify application bottlenecks through early Performance Testing (Before completion of SIT and start of UAT)
Model the application performance at design stage to validate your Non Functional Requirements
Proactively model application performance through Performance Test and once the application goes live
Proactively manage application infrastructure requirements once the application goes live
Proactively monitor application performance in production (OS, Application, Transactional) to track SLA’s and capture required metrics for purposes of Performance Modelling & Capacity Management
Work closely with business to forecast application performance and associated infrastructure requirements to meet growth in business workload
Prevent a meltdown on go live or in production
Prevent fire fighting in production and rather focus your time and energy on building required application functionality

5. Performance Engineering Life Cycle
Software Development Life Cycle
Functional Requirements Gathering
Architecture & Design
Build Application
System Test, System Integrated Test & UAT
Deploy Into Production
Performance Engineering Life Cycle
Non Functional Requirements Gathering
Design for Performance &
Performance Modelling
Unit Performance Test &
Code Optimization
Performance Test
Monitoring & Capacity Management

6. Holistic View Of Performance
Txn Performance
- Resp Times, etc.
Application Performance – Operations/Sec, Messages/Sec, Transactions/Sec, etc.
Infrastructure Performance – CPU Utilization, Memory Utilization, Disk IOPS, etc.
Network Performance – Packet Loss, Jitter, Packet Re-ordering, Delay, etc.

7. Activities Involved in PE
Software Development Life Cycle
Functional Requirements Gathering
Architecture & Design
Build Application
System Test,
System Integrated Test & UAT
Deploy Into Production
Performance Engineering Life Cycle
Non Functional Requirements Gathering
Design for Performance &
Performance Modelling
Unit Performance Test &
Code Optimization
Performance Test
Monitoring & Capacity Management

8. What does PE mean to different stake holders
User
Expectation
Business
Gains the ability to grow services and provision additional customers onto the existing or new platform as business grows
CTO
Intends to see an application platform delivered that meets the organizational strategic requirements and scales as business workload grows
CFO
Intends to get the most bang for his buck
Program Manager
Is able to deliver an application on time, on budget while meeting the Non Functional Requirements as agreed with the customer
Developer
Intends to write code that meets the Performance Targets documented by the overall Non Functional Requirements
Systems Administrator
Expects to inherits an application that optimally uses infrastructure resources, doesn’t fall over in production, is easy to manage, doesn’t have performance bottlenecks, scales as expected to meet user workload and meets business & IT SLA’s
Capacity Planner
Recommends infrastructure requirements based on business workload and application architecture. Works proactively with application teams to recommends application optimization and additional infrastructure required
Performance Tester
Validates application performance based on defined Non Functional Requirements and expects to see the application meet defined Non Functional Requirements
End Customer
Expects to use an application that provides a great end user experience

9. Roles Performed by the Practical Performance Analyst
Phase
Role Performed
Requirements Gathering
Determine Business Volumes & Growth plans
Determine Non Functional Requirements
Design
Validate Application Architecture
Validate Infrastructure Architecture
Validate Infrastructure Design
Determine Infrastructure Capacity Requirements
Build & Optimization
Set performance targets for developers
Validate outcome of Unit Performance Tests
Recommend optimization to Code
Recommend optimization to Application Design
Recommend optimization to Infrastructure Design
SIT & UAT
Begin validating Application Performance for functionality that’s available
Begin Tier Performance Tests for functionality that’s available
Test, tune & optimize Performance for functionality that has been released
SVT
Execute End to End Performance Tests
Validate Performance End to End
Identify applicable bottlenecks
Use Diagnostics tools to identify bottlenecks, tune & Optimize application
Ensure application meets its Non Functional Requirements
Evolve Performance Monitoring Requirements
Pre-Go live
Setup Performance Monitors for Network, OS, Application, Business Txn
Set alerting for various Performance metrics
Setup capture Performance metrics for purposes of Capacity Management
Go-Live & Post Go Live
Monitor application for potential breaches in SLA’s
Identify hotspots using low overhead transactional tracing & diagnostics tools
Model application performance and predict capacity impacts for growing business workload

10. What is Proactive Performance Management
Performance Requirements Analysis
Performance Modelling & Capacity Planning
Build & Optimization
Performance Testing
Performance Monitoring
Capacity Management

11. Costs of Addressing Performance Across the SDLC
Requirements Gathering Phase – Lowest cost since you don’ t have designs yet and you are starting from a fresh slate. You’ve got the opportunity to document the appropriate Non Functional Requirements based on business requirements.
Design Phase – The application designs and infrastructure designs are coming together. You still have an opportunity to influence Non Functional Requirements. You haven’t missed the bus and have the opportunity to influence the design process.
Build Phase – Slight more expensive since the designs have been locked down, your developers have begun writing code according to specifications. Not having Non Functional Requirements means that you can’t really set developer performance targets. You will start feeling the pain once you get into SIT & UAT since you developers are only focussed on application functionality and don’t have visibility of any of the Non Functional Requirements
Testing Phase – Defects found at this stage are expensive to fix since they require you to raise defects and go through the whole change management and QA process. Changes to application or infrastructure design are very expensive to fix. Re-design of any application components due to performance bottlenecks could set the program back by weeks or months.
Go Live – The most expensive to fix. Your application is live, performance issues at this stage impact the business’s credibility, your credibility and the credibility of the whole QA process across the program. You should consider changing jobs and taking up something you are better at before you get fired.

12. Challenges in Addressing Performance
Lack of understanding of Performance Engineering concepts
Lack of willingness to invest in Performance Engineering tasks
Lack of skills to support Performance Engineering roles
Focus on application functional requirements and application design at the early stages of the program
Expensive tools to perform tasks related to Performance Engineering across the Software Delivery Life Cycle
Gaps between SVT & Production infrastructure
Delays due to delayed code drops, delayed SIT/UAT phases that reduce effective Performance Testing
Lack of diagnostics and monitoring frameworks to proactively identify performance bottlenecks
Lack of Capacity Management tools to proactively manage performance and provision infrastructure capacity

13. Tooling for Performance
Performance Requirements Gathering
Capacity Planning
Performance Modelling
Performance Testing
Performance Monitoring
Capacity Management

14. Thank You
trevor@practicalperformanceanalyst.com