Do Adding Cores Improves The System's Performance?

Hardware and Programming Language

If I have no understanding of -- sysem's architecture, how the system is designed and implemented technically knowing its business purpose, then I cannot test for performance rationally and technically, 

In this context, the awareness and understanding of below is necessary and important.

1. The infrastructure where the system and its services are deployed and consumed
2. The hardware on which the system is deployed
• The understanding of the hardware along with its limitation
3. The hardware on which the service of the deployed system is consumed
• The limitation of consumer's hardware
4. Understanding the CPU and its Cores
• How we are programming the threads to exeucte on these Cores?
5. The programming language used to implement the system; this play a vital role
• Does it allow the threads to run on two and more different cores at a time?
• Or, does it confine the threads to run on one Core?
6. The way in which we have programmed the system for its instruction execution at a thread (subroutine) level
• How the threads are implemented and how it exeuctes on a CPU and its Cores?

I should be aware of above said information when building high performant system and testing for the performance of a system.

The value and benefits of these information are not just limited to performance testing alone. It also helps in testing for seucrity and functionality.  The awareness of these information will give you an edge in the testing for performance.

CPU Cores and Software System's Performance

I hear this often and especially during the businness seasons time:

"We will add more CPU with more cores. This will improve the exeuction time and improves the performance.  The business will not be impacted."

Does this make sense technically?  What's your thought on above statement as a Test Engineer testing the system for different quality criteria?

If I do not have awareness on information that I said above, I will not be in a position to test and advocate better for performance.

Do Cores Added Reduce the Exeuction Time?

By just adding more cores to a CPU, it does not always speed up a program's exeuction time.   

I learn, if a program which is designed to run on multiple cores have threads, that must run on one core, then this will be a limitation for the maximum speed [by reducing execution time] which we can achieve by adding more cores.

Also, the programming language used will have a role.  If the programming language uses Global Interpreter Lock (GIL), then it makes sure that a process created out of it can run only one instruction at a time, despite of the cores it is currently using.  That is, though a process created has access to multiple cores in a given time, the insturctions will be running on just one core.  Which means, the threads cannot run on multiple cores.  The instruction will be running on just one core and just one thread at any point in time.  Eventually, this leads to higher exeuction time for a process of program.

Should I say high exeuction time is a high performance and high performant system?  That is contextual!  What do you say?  What should a consumer of the service (business) say about this performance?

To summarize, adding multiple cores to a CPU, does not necessarily speed up the exeuction time for a program.  It is dependent on how we have designed and written the program and the programming language used.

To know more about GIL

• Global Interpreter Lock -- https://en.wikipedia.org/wiki/Global_interpreter_lock
• https://langdev.stackexchange.com/questions/1873/what-is-a-global-interpreter-lock-and-why-would-an-interpreter-have-it

Performance Test Report: Between the Effective and Ineffective Reports

 

In this post, I'm picking the thirteenth question from season two of 100 Days of Skilled Testing.

What is an effective way of reporting performance test results and mention some tools you have used in test execution, analysis, and reporting?

I see two questions.  I see it is not a wise attempt to learn these two questions combined as one.  In my opinion, the second question added, it dilutes and make the whole question vague.

What Should a Report Do?

The report should be contextual, compelling, influencing, and targeted to the intended audience to act upon on making a decision.  The software testing report is not an exemption from it.

The performance testing report should know

• Who are its audiences?
• How they read, relate and understand the information?

If this is ignored, the report will not serve the purpose of commissioned testing.  The effectiveness of a report cannot be determined solely on how the stakeholders responds to it.  

On understanding the risks and problems in the system's current capability, mentioned in the report, the stakeholder might not respond with an action to tune the performance aspects.  This could be for multiple factors including that of business.

Note that, a skilled and problem solving engineer understands the business and how it drives.  Just being technically skilled will not help an engineer to grow in a longer run in her or his career.  The system's performance tuning decisions most times will be driven by business.

Did the report persuade the stakeholders with an awareness, mutual understanding and agreement?  The report should drive this conversation.  If not, we have a problem.

On reading the performance testing report, do the stakeholders get an informed awareness on what happened during testing in the present capability of a system's performance criteria?  Do the stakeholders understand and mutually acknowledge how it benefits and costs the business?

This is the foremost value serving expected from a testing report.  If not, I look at how the data and story is presented in the report.

The bottom line is, did we mutually acknowledge, agree and understand on current capability and consequences?  If not, the basic purpose of the report is not met.

Performance Testing Report

The software testing is a high technical activity.   You agree or not to this, but, this is the reality.

Testing for performance is technical investigation activity. It includes the orchestrated study in correlation of 

• hardware, operating system, network, tech stacks & software used in SDLC, architecture, designs, certain decisions, people, business and you - the test engineer.

The fundamental in-depth awareness and knowledge of these areas is essential and a necessity to analyze the performance's aspect.  The performance testing report will show this trait of you as a test engineer.

We have stakeholders who work in technical area and in non-tech area.  How to compile the effective performance testing report?

There is no one way or defined way of writing an effective performance testing report.  Figure out what works in context of your testing to have a effective report knowing - What Should a Report Do?

Outline of Persuading Performance Test Report

It is a technical story telling in a non-technical way with data, pictures, comparison by relating, metaphors, and contemporary history.  I compose the performance testing reports in line with business targets and objectives set.  I provide a metaphors to relate and know the value and cost.

At times, I will have two reports.  I share it with respective stakeholders.

• One with non-technical summary and conclusion
• The other with technical details, analysis and data from investigation

Sometimes, I include the above two reports in one report based on the context.

In overall, this will be in minimum as part of my performance testing report to start.

1. What part of the system is being tested?
2. Why that part of the system is being tested?
3. Mentioning the vague performance requirements gathered from stakeholders.
4. Refining and precising the performance requirements to be specific, contextual and deterministic.
5. Who are the stakeholders of this report?
• What sections the respective stakeholders to refer for the analysis and outcome?
6. Problem statement of the performance testing statement
7. Brief summary of performance testing outcome. [TLDR]
1. What aspect of system's performance is evaluated and why?
2. Brief summary of performance test carried out and outcome.
8. Detailed Report with Technical Details
1. Analysis and Technical Investigation
2. Representation of data which is analyzed
3. Identification of bottlenecks, risks, problems and its symptoms
4. Summary of the test's outcome

You don't have to stick on to one format or a template.  Figure out what works well in your case so that the intent of your tests and outcome is understood by stakeholders.  Give a structure to your report!

The performance testing reports will have metrics, graphs, numbers and proposals.  The presence of metrics, graphs, numbers and the other said, does not make the report effective.  Then, what makes it effective?  When you call it effective?  When you accept it is not effective?  Only, you can figure it out to your context.  I can assist you here; pull me in.

There is no good [effective] report or not good [ineffective] report.  The report is either

• From a team with skills, experience, trained, and practicing
• From a team which is not trained, and, not practicing

Performance Testing - What to Know Before User Behavior and Traffic Pattern?

 

This blog post is in series of 100 Days of Skilled Testing.  I see, I do not have to pick every questions asked in this series.  I pick and share to which I see, I can add value.

The twelfth question from the season two of 100 Days of Skilled Testing, is:

What strategies do you use to simulate realistic user behavior and traffic patterns when conducting performance tests?

The twelfth question asked is vague and it needs to be refined for preciseness to pick it up and continue.

The Question and the Gap

I see the below are missing in the above asked question:

1. What aspect of performance is under evaluation?
2. What is the system that is being evaluated for a performance's aspect?
3. What part of the system is being evaluated for a performance's aspect?
• Queuing? Messaging? Database I/O? Memory? Space? CPU? Client Performance? Functional Module?
4. Who are the users?  What are their personas?
5. How and where the users are accessing the system?
6. What is the context of users accessing this system?
7. What is the geo location of users who are accessing this system?
8. How long these users are connected by accessing this system?
9. Are there any differences among these users in their roles and privileges in accessing this system?
10. Can the user access system through multiple interfaces?
11. Are you assuming the user is on web browser and mobile apps to access this system?
12. Is this system you are referring to, is a software system? Or any other system that is controlled environment like - access door, elevators, etc. ?
13. You are asking to simulate the user behavior and traffic pattern.  Should I assume, I and you know or agree to any volume of user?  And, all these users are here for the same purpose when accessing the system?
14. Are you considering any time or at a particular time when talking about the traffic pattern?
15. Are there any unrealistic users who is accessing your system?  You say 'realistic user'.
• Do you see that bots and non-human are also allowed as a user in your traffic?
16. Have you evaluated this earlier in your system?
• If yes, do you have the history and data for user behavior and traffic pattern?
• If you don't have, do you allow to use or have your competitor's user behavior and traffic pattern data? 
17. What is the tech stack of your system?
• What part of your tech stack, you want to evaluate with this user behavior and traffic pattern?
18. What is the architecture of your system?
19. What part of your system and its architecture is being evaluated with this user behavior and traffic pattern?
20. Are you running this exercise for the first time?  If not, where I can refer to previous exercises?
21. How the interaction and events are handled from its start to completion?
• What all are needed to complete the transaction in work flow?
• How this transaction can go invalid for lack or incorrect data, state and action?
22. What is spike, drop, saturation, expected, unexpected, and average numbers in the traffic coming in?
23. What do you understand by traffic?  Do you mean number of requests coming in?
• Do you mean the being committed I/O operations?
• Do you mean the response received at the other end?
• What is the definition of 'traffic' in this context?
24. What is that you want to study and evaluate by the User Behavior and Traffic Pattern information gathered in this context?

Using the above questions, I will get an idea to proceed.

I will build a model from information I collect using above asked questions.  This model we will used to further in testing for a performance's aspect.  The value added to the performance test depends on this model as well.  To get a better model in context, it is useful to address the gaps.  From here, I start to think further.

What do you ask and look for when building a model for User Behavior and Traffic Pattern?

Performance Testing - The Unusual Ignorance in Practice & Culture

 

I'm continuing to share my experiences and learning for100 Days of Skilled Testing series.  I want to keep it short and as a mini blog posts.  If you see, the detailed insights and conversations needed, let us get in touch.

The ninth question from season two of  100 Days of Skilled Testing is

What are some common mistakes you see people making while doing performance testing?  How do they avoid it?

Mistakes or Ignorance?

It is mistake when I do an action though I'm aware that it is not right in the context.

I do not want to label what I share in this blog post as mistake.  But, I call it as ignorance despite having or not having the awareness, and the experience.

The ignorance said here is not just tied to the SDLC.  It is also tied to the organization's practice and culture that can create problems.

To this blog post's context, I categorize the ignorance in these categories -- Practitioner and Organization.

1. Practitioner's ignorance
• Not understanding the performance, performance engineering, and performance testing
• When said performance testing, taking it as - "It is load testing"
• No awareness on what is performance and performance engineering
• Going to the tools immediately to solve the problem while not knowing what is the performance problem statement
• Be it web, API, mobile or anything,
• Going to one tool or tools and running tests
• No much thinking on how to design the tests in the performance testing being done
• Ignoring Math and Statistics, and its importance in Performance analysis
• No idea on the system's architecture, and how it works
• Why it is the way it is?
• The idea of end-to-end is extended and used in testing for performance and having hard time to understand and interpret the performance data
• How many end-to-end your tests have identified?
• Can we test for performance to all these identified and unidentified end-to-end?
• Relying on the resource/content in internet and applying or using it in one's context without understanding it
• No idea on the tech stack and how to utilize the testability offered by it in evaluating the performance
• Not using or asking for testability
• Getting hung to most spoken and discussed 2 or 3 tools on the internet
• Applying tools and calling out it as performance testing
• No attempting to understand the infrastructure and resources
• How it impacts and influences the performance evaluation and its data
• Idea on Saturation of resources
• Thinking it as a problem
• Thinking it as not a problem
• Not working to identify where will be the next bottleneck when solving a current bottleneck
• What to measure?
• How to measure?
• When to measure?
• What to look when measuring?
• Not understanding the OS, Hardware resources, Tech Stacks, Libraries, Frameworks, Programming Language, CPU & Cores, Network, Orchestration, and more
• Not knowing the tool and what it offers
• I learn the tool everyday; today, it is not the same to me compared to yesterday
• I discover something new that I was not aware of what it offered and exist
• I learn the new ways of using the tool in different approaches
• No story in the report with information/image that is self-describable to most who reads it
• And, more; but the above said resonates with most of us
2. Organization's ignorance
• At the org level, for first and to start, it is ignorance in Performance Engineering
• Ignoring the practice of performance engineering in what is built and deployed
• Thinking and advocating, increasing the hardware resources will increase and better the performance
• In fact, it will deteriorate over a period of time no matter how much the resources are scaled up and added
• Ignoring the performance evaluation and its presence in CI-CD pipeline
• The performance tests on CI-CD pipeline should not take beyond few minutes
• What is that "few minutes"?
• Not prioritizing the importance of having the requirements for Performance Engineering

Recently, I was asked a question - How to evaluate the login performance of a mobile app using a tool "x"?

In another case, I see, a controller having all HTTP requests made when using web browser. Running these requests and trying to learn the numbers using a tool.

I do not say this is wrong way of doing.  That is a start.

But, we should NOT stay here thinking this is a performance engineering and that is how to run tests for learning a performance aspect[s].

To end, the performance is not just - how [why, when, what, where] fast or slow?  If that is your definition, you are not wrong!  That is a start and good for start; but, do not stick on to it alone and call performance.   It is capability.  It is about getting what I want in the way I have been promised and I expect; this is contextual, subjective and relative.  The capability leads to an experience.  What is that experience experienced?

Sometimes, serving the requests by what you call as slow, is a performance.  What is slow, here?

The words fast and slow are subjective, contextual and relative.  It is one small part of performance engineering.

That said, let me know, what have you been ignoring and unaware in practice of Performance Engineering & Testing?

Waterfall or Agile: Testing for Performance - Where to Start?

 

Do you understand the Agile?  I have shared my understanding here; give it a read.

The eighth question from season two of 100 Days of Skilled Testing is:

Can you share some best practices for conducting performance tests within an Agile development environment?

Best Practices and the Agile

The irony is, the Agile says, there is no best practice.  It asks, to tailor and fit the practice to the context so the continuous delivery and value is delivered consistently upholding the Agile's principles.  

Yet, we talk about the best practices in the Agile's context, like the eighth question asked here.

What is the effective way to test in the continuous delivery?

As a test engineer, how can I start thinking and testing for performance from the inception of a feature's thought?  I see, it is not hard to do so.  As you read further in this post, you will have a perspective and awareness to do it.

Performance in Waterfall and Agile

I learn, the performance is an experience.  It does not differ because of the Waterfall or Agile.  If the performance is not a pleasing experience, it will impact stakeholders no matter it is Waterfall or Agile.

But, the question when evaluating for the performance is -- where to start, when to start, how to start, and with what to start?

As of today, I do not see differences in the mindset and skills one has to have for testing of performance in Waterfall and Agile.  Could be the approach differs in certain phases here; otherwise, I see the same in both practices.

I will rephrase the eighth question to this:

What is your practice to evaluate the performance right from the start of product development in your project?

I do not want to wait until to hear -- the development is completed and deployed; now we can start running the performance tests.

What can I do as part of performance tests from the first day of development and first commit?  This is my intent and area to look in strategizing the testing and tests.

The Culture of Engineering

At the start and end of the day, when we developers start and finishes the work,

• How the work is done and why, is defined by the engineering culture practiced by that organization.
• The Performance Engineering of the software products and solution being built will be driven the by the culture practiced.

The Test Engineering and how we test and automate will be driven by the culture of engineering practiced in the organization.

Writing the code not just for building the functionality, but, also for performance is a culture driven factor.  The organization's culture for engineering practice drives it!

Testing for Performance - Where to Start?

I'm sharing my research work that I'm doing and experimenting on performance engineering and performance tests.  I'm seeing the results and value out of it and so are the stakeholders.

Today, we are getting skilled in exploring and testing without the requirement document and SLAs in hand.  Isn't it?  Haven't you?

I use my MVPT to figure out what are the minimum performance tests for the feature.  As part of this, I will explore with help available aids to evaluate the performance.

To start, I will use these questions to figure out the performance tests:

• What is the minimum viable questioning performance tests that you have got to test this feature?
• What is the minimum viable questioning performance tests that you have got to test this workflow?

Unit Tests for Time and Space Complexity

I will work closely with programmers to gather information on below when the code for the feature is committed as part of Unit Tests.

• The execution time taken by the code of that feature - the Big O Notations for space and time complexity
• Usually the Unit Tests focuses on functional tests and clean code practice
• But, when we test team ask and push for performance data, this can come as part of Unit Tests
• An architect or a principal engineer can set an expectation on
• What should be the time and space complexity of a code for a feature?
• Each functions and blocks need to be evaluated on this
• As said earlier, this depends on a engineering practice culture of an organization
• If the culture wants it, it will be there; else just the functional code will be delivered and not the performance code
• If the time and space complexity analysis outcome is not as expected, the code written has to rethought and refactored
• The review process need to put it back
• The comment with data has to be published
• This will be useful to model the performance tests by test engineers who will be working on performance tests
• Doesn't it look a like a effective useful practice as part of Performance Engineering right in the early stage?
• This is very well applicable to projects running on Agile or Waterfall

Do you have this in your project and Unit Tests written?

The time and space complexity questions should not be confined just to the SDETs [test engineer] interview.  A test engineer has to ask for it and apply it in her or his day-to-day work.

Profiling Tests by Test Engineers

We testers do not get into product's code analysis.  We have to build skill to run the profiling on product's code and analyze the resources data.

• Test Engineers can test the feature's code with the help of IDE's profiling (runtime analysis) and collect the performance data by identifying the performance bottlenecks
• This runtime analysis can profile for
• Memory snapshots
• Thread analysis
• Monitoring resources
• CPU and allocation profiling
• And, more
• The problems and risks can be reported upon analysis
• Compare the two different solution's approach performance data

This information will tell and indicate where is the risk and problem when we deploy the code.  In my opinion, this is a useful information in modeling further performance tests.  This information is first-hand information which is very powerful before we start using any other performance testing strategies and tools to aid the tests.

Get Started with Performance Engineering and Tests

These are available in the IDE.  We think of performance testing tools and ask how to test for performance.  To be precise, we test developers (test engineers) should change our mind and shift for first.  If not, as I say, we will be the bottleneck for first to ourselves.  Did you know this way of testing for performance?  Why not you introduce this in your project and organization?

If seen, these test practices can be used right from the day we commit the feature's code. This is a place to start for the performance tests.   This will be a differentiator together with MVPT and guides the MVPT to design effective performance tests in the context.

I do not say these are best practices and there is no best practices.  But this is a useful practice when the organization and stakeholders ask for it.  Let your organization and stakeholders know how well you can test for performance right from first commit of product's code.

To stop and end here,

1. Just do not test for functionality from day one, also test for the performance from the day one.
2. Influence your organization's engineering culture and developers not just for developing functional code, but, also for the performance code

Is Performance a Perception to an Engineer and User?

 

When hearing about performance from customers and engineers on team, I see each are having a perception of it on using a product.  To one it was fast enough, to another it was as usual and for one it was too slow.  Each are expressing their perception.  But, what is the performance?

What is Performance?

I see, understanding and knowing "What is performance?" is important for everyone who is involved in building the software system and product.  In my opinion, this should be the start point.  It is beneficial, when everyone has a shared common understanding to it as a team and business.

Performance is an emotion to a user!  Technically, the performance has multiple facets to it for understanding the capability of a system and its sub-systems.

Facets of the Performance

What facet do you consider and call it out as Performance?  This is another point where most of us do not align.  For example, below are the different facets that we usually hear and read a lot:

• Heap and Memory
• Threads
• Not supporting for concurrency
• Not handled well in concurrency
• Holding up other processes and causing bottleneck cases
• Memory Leaks
• Concurrency
• Memory not reclaimed
• and, more ....
• CPU consumption
• Open connections and its I/O
• Held up in processing requests
• No enough resources to process
• and, more ....
• DB I/O
• Open connections
• Unindexed data
• SPs and Queries holding the transactions
• Incorrect configurations of DB Server and nodes
• and, more ...
• Disk I/O
• Running out of space
• RW I/O not responsive
• Network consumption
• Unmanageable transactions
• Transaction's data, size and time
• Latency
• Latency in which interfaces?
• Ineffective caching, queuing and messaging
• GUI not rendered or painted
• GUI exhibiting jank behavior
• GUI partially rendered
• GUI not in a interactive state
• GUI not responding to an action
• GUI and UI loading multiple times with no room for interaction 
• Terminal yet to return and show the prompt
• Older and deprecated libraries with latest dependencies
• Server, orchestration, and sub-systems configured incorrectly
• Hardware resources and its specifications used in a context
• Display refreshing rate and frames lost with GUI rendered
• Heat dissipation
• From the hardware
• Experienced in the environment
• Time taken for a request to reach the actual end point
• Execution time on receiving a request
• And, more...

Further we have classified it to frontend and backend; both are important and equally needed.  The webpage has got different KPIs and metrics to determine where do its performance stand.  Likewise, for backend.

Which facet of performance need to be evaluated and in which phase?  Why?  The perception will be established when testing, on how we test it, and how one uses the product.

With all these for performance, where to start and what to look at?  This is one of the question with which we are left in Waterfall and Agile.  That is where the eighth question of 100 Days in Skilled Testing comes in -- Can you share some best practices for conducting performance tests within an Agile development environment?

Have you asked these questions to yourself and team?

1. What is performance to you and to your stakeholders?
2. What should I consider in evaluating for the performance of your software system?
3. What is the practice I want to pick to evaluate the performance?
4. Where do I start and how?  

Software Engineering - The Unquestioned Understanding of Client in Testing

Client - The Unquestioned Understanding

When asked or said "client" or "client-side", most of us assume or take it as:

• Web page displayed in the browser
• Mobile apps - Android and iOS apps
• Desktop applications

I see this is one of the unquestioned understanding and assumption in the Software Engineering.  While it is not wrong, the client does not always mean -- a web page displayed on browser, mobile apps, desktop applications, a terminal, etc.

The client is one of the subjects which we have not attempted enough to understand in Software Testing & Engineering.

A client is one who consumes the service in form of a response, and then does what it has to do.

Client - The Contextual Entity

The entity which takes the a client place [role] is entirely based on the context.  That web page displayed on a browser is a client per some model.  So is the mobile apps.  A service looking for data from Redis is a client too.

The client can be within the backend system which requests another entity to process its request and awaits for the response.  This client is not always a mobile app, web page on a browser, or a terminal where I'm working with commands.  Do you see that?

Next time when you hear the word client, ask for the context and know who is the client that is being discussed.

Client's Awareness in Performance Tests

By now, you should be breaking your assumption and the myths around the word "client".

In testing for Performance, it is critical to be aware who is client, when and how?  Evaluating this client will not be like evaluating a web page on a browser or the mobile apps.

The fifth question from season two of 100 Days of Skilled Testing, is:

How does client-side performance testing contrast with server-side performance testing, particularly in their objectives and area of emphasis?

Hope now you will question when said client-side performance,

• What client are we talking here?
• Where do this client sit in the system's architecture.

Based on this information,

• How the tests for performance is approached and executed for a client, differs.
• What is collected and observed to evaluate the performance of a client, differs.

This blog post is not to illustrate the different clients and how evaluate it for performance.  When the question talks about a particular client and in a context, I will share the approach, and how to evaluate the same.

To end, have we explored the clientless interface?  How to test this interface?

  

Web Client Performance: Webpage's Response Time and HTTP Requests -- Part 1

I'm practicing along with my colleague Chidambara, on Web Client Performance Testing (WCPT). While we practice together, we are learning, how to assess the current capability of the web page and then how to interpret the same.  Why I say this, because when I test, I will make a report; that test report as to help one to decide and assist in taking the necessary action if it has to be taken. If not, the purpose of the test report might just bound to know what did I test and what is my interpretation. For this, I need not write the test report.  The same with automation as well, isn't it? We will get the report on running the test suite and this report will be used further to decide what to do based on our interpretation of it. Coming back to WCPT, I happened to learn it this way and sharing my learning with my fellow tester.

I picked a Google India search page and monitored its requests and response. At time of testing, I used Firefox in private mode. I noticed total of 16 requests were fired and close to 1.4 MB data were transferred. Overall it took 4.62 seconds on 100 Mbps bandwidth internet line. Below picture reads the requests fired and its timeline.

HTTP requests fired from Google Search India page

I notice, first two redirection taking total of 294 ms, and then 484 ms to load the html document. In total, to load the html document, 778 ms is used. This is close to a second. If I had to make it to round figure, say 1 second to load the html document. Without html document, the web page will not get loaded and for this reason html document will be the first content to get downloaded on client i..e on the browser.  Notice that there are two redirects with HTTP status code 302.

I will walk through in a blog post how the redirects affects the web client performance potentially. I and Chidambara, practiced the same few days back.

Moving ahead, I see other 3 seconds are used to download the images, stylesheet (CSS) and scripts. This tells, more time is taken to download these elements of the page then the html document. When looked into other web's webpages the same is observed during time of testing.  With that, I learn, these elements are the time consumers if not handled well thereby showing the slow response time. Slower the response time is, i.e. the more time is taken to load the functional webpage.

Now you see, while carrying out the functional test you also test partially for the performance of it, and vice versa.

The 'capability' i.e. performance attribute of the webpage will be -- "how quickly it loaded on the client i.e. what is its response time".

Note that, the expectation is, it should be functional and  the experience of using it should be pleasant to the user; these are the implicit expectations with the words 'capability' and 'response time'.

In above picture, the total time for receiving the html document is 778 ms. But, the event DOMContentLoaded is fired after 1 second and somewhere it looks near to the mark of 1.2 second. Where did the 442 ms go then? On my network bandwidth of 100 Mbps and machine configuration with 8 GB RAM, still this is a question to me. Then what will be in other network bandwidth and client's machine configuration? Why DOM parsing took time?

I see there is JS being received i.e. in 8th request. I'm not sure if is synchronous or asynchronous. Technically where there is no dependencies between the scripts or any other page elements, keeping it as asynchronous helps.

Then there is a CSS being received in last second request. If the CSS isn't received well before, then page loading has to wait for it as the style cannot be defined for the parsed DOM of loaded html document.  It is a thumb rule to keep CSS in the top requests while receiving from the server. But context of the website's design can change this thumb rule.

If this gets tested, can the response time of the Google India search page can come close to 3.3 to 3.5 seconds?

If this is just for one webpage of a website, how many webpages do the product I'm testing, have? Now I understand very much better than ever that, like functionality is coded into the product, the performance as well should be designed and coded in equal importance.  I derive my tests with such thought process as it serves me to be the base in building the tests and for sampling the variation and interpretation of test observations.

What did I learn here?

These are key learning when I happened to interpret the Web Client's performance

• More the number of HTTP requests, the response time increases for the webpage
• Lesser the number of HTTP requests, it is good from point view of webpage's response time and performance
• The html document takes minimal share in the total load time of the web page and rest of the time is taken by the webpage's element
• Handling and optimizing this is important for better performance of web client
• More the page weight, more the response time for webpage
• Need to test and figure out is there any way the page weight can be optimized, so the response time for webpage will be fast
• If said, 15% of time is for html document of the webpage and then other 85% is for the webpage's element, then the problem area is evident with respect to response time
• If fine tuned the client for better performance, the experience for targeted user should still be pleasing with better response time
• Upon this, if server performance is optimized, then do targeted user say, "it is just like this, so fast"? I do not know; but as a practicing tester I see, fine tuning the performance of web client is possible for a tester while she or he tests the website for functionality or any other quality criteria. In parallel, if taken care of server performance based on contextual learning from the tests observation, it will be very much useful.
• Know this when looked at webpage
• Number of HTTP requests fired; 
• time taken by each requests; 
• what each requests carries from client and back from server to client; 
• size of the HTTP request transaction; 
• page weight and contribution by each elements in the webpage; 
• know when did DOMContentLoad event got fired in the timeline;
• in above picture it is marked with blue line in the timeline
• it is fired when the html document is completely parsed and loaded without waiting for other elements of the webpage i.e. css, js, images etc.
• know when did Load event got fired in the timeline;
• in above picture it is marked with red line in the timeline
• it is fired when the page elements are loaded and finished loading
• overall response time for the webpage;
• understand what each page element is and why it is needed;
• it is very much important from aspect of testing to know is it actually needed for the webpage or website
• if it is not needed, then as a tester I should be in position to advocate my observations out of tests
• if it is needed, then as a tester I should be in position to advocate my observations out of tests and how it can be tuned and optimized

It is important to know what is HTTP and how the web communicates. So that we understand the influence of bandwidth and latency on the response time. In next post, I will share what I have understood for the same. Later in subsequent will share, how I and Chidambara progressed in learning and practicing of this.

Testing for Web Performance: Why I want to share ?

I was practicing with a fellow tester and he expressed that he wants to practice performance testing. I too have that wish i.e. to practice performance engineering and testing. I try to find the opportunity each time to practice this and look out for fellow testers and mentors who can assist me here. However I do not wait for mentor now though I want one. Instead I will start my practice and I learn from my practice as I practice.

May be, as me there could be other testers who wants to practice the performance testing. I wish to share my learning and practice here, in the simplest and short way.  

I have heard Rahul Verma saying, "replace the word 'performance' with the word 'capability', when you hear a word performance". I feel, it makes more appropriate and meaningful to look it as a 'capability' when said 'performance'.

With the label 'Web Performance', I will share what I'm learning, practicing and thinking for web performance in last few years. When said, 'web', it is not just the website; it is the web that connects different interconnected systems. I will be sharing my learning on one aspect of web which is connected and communicating via HTTP protocol.