December 29, 2017

Srikaanth Kumar

Performance Testing Latest Interview Questions And Answers


Explain What Is Performance Testing?

Performance testing is done for quality assurance. It involves testing software application to make sure that the software is working well under their expected workload.

Why Does Jmeter Become A Natural Choice Of Tester When It Comes To Performance Testing?

JMeter tool has benefits like :

It can be used for testing both static resources like HTML and JavaScript, as well as dynamic resources like Servlets, Ajax, JSP, etc.

JMeter has a tendency to determine the maximum number of concurrent users that your website can handle
It provides a variety of graphical analyses of performance reports

Mention What All Thing Involves In Performance Testing Process?

Right testing environment: Figure out the physical test environment before carry performance testing, like hardware, software and network configuration

Identify the performance acceptance criteria: It contains constraints and goals for throughput, response times and resource allocation

Plan and design Performance tests: Define how usage is likely to vary among end users, and find key scenarios to test for all possible use cases.

Test environment configuration: Before the execution, prepare the testing environment and arranges tools, other resources, etc.

Test design implementation: According to your test design, create a performance test

Run the tests: Execute and monitor the tests

Analyze, tune and retest: Analyze, consolidate and share test results. After that, fine tune and test again to see if there is any enhancement in performance. Stop the test, if CPU is causing bottlenecking.


List Out Some Of The Parameters Considered For Performance Testing?

Customer preference tool
Availability of license within customer machine
Availability of test environment
Additional protocol support
License cost
Efficiency of tool
User options for testing
Vendor support

What Is Load Testing?

Load testing is to determine if an application can work well with the heavy usage resulting from a large number of users using it simultaneously. Load is increased to to simulates the peak load that the servers are going to take during maximum usage periods.

What Is Modular Approach Of Scripting?

In Modular approach, a function is created for each request (e.g. login, logout, save, delete, etc.) and these functions are called wherever required. This approach gives more freedom to reuse the request and saves time. With this approach it is recommended to work with web custom request.

What Activities Are Performed During Performance Testing Of Any Application?

Following activities are performed during testing of application:

Create user scenarios
User Distribution
Scripting
Dry run of the application
Running load test and analyzing the result

Explain The Sub-genres Of Performance Testing?

Following are the sub-genres of Performance Testing:

Load Testing: it is conducted to examine the performance of application for a specific expected load. Load can be increased by increasing the number of user performing a specific task on the application in a specific time period.

Stress Testing: is conducted to evaluate a system performance by increasing the number of user more than the limits of its specified requirements. It is performed to understand at which level application crash.

Volume Testing: test an application in order to determine how much amount of data it can handle efficiently and effectively.

Spike Testing: what changes happens on the application when suddenly large number of user increased or decreased.

Soak Testing: is performed to understand the application behavior when we apply load for a long period of time what happens on the stability and response time of application.

Mention What Is The Difference Between Performance Testing And Functional Testing?

Functional Testing

To verify the accuracy of the software with definite inputs against expected output, fuctional testing is done
This testing can be done manually or automated
One user performs all the operations
Customer, Tester and Development involvement is required
Production sized test environment is not necessary, and H/W requirements are minimal.

Performance Testing

To validate the behavior of the system at various load conditions performance testing is done.
It gives the best result if automated
Several user performs desired operations
Customer, Tester, Developer, DBA and N/W management team
Requires close to production test environment and several H/W facilities to populate the load.

How Do You Identify Which Protocol To Use For Any Application?

Previously Performance tester had to depend much on the development team to know about the protocol that application is using to interact with the server. Sometimes, it also used to be speculative.

However, LoadRunner provides a great help in form of Protocol Advisor from version 9.5 onwards. Protocol advisor detects the protocols that application uses and suggest us the possible protocols in which script can be created to simulate the real user.

Mention Different Types Of Performance Testing?

Load testing
Stress testing
Endurance testing
Spike testing
Volume testing
Scalability testing

List Out What Are The Common Performance Problem Does User Face?

Longer loading time
Poor response time
Poor Scalability
Bottlenecking (coding errors or hardware issues)

List Out Some Common Performance Bottlenecks?

Some common performance bottlenecks include:

CPU Utilization
Memory Utilization
Networking Utilization
S limitation
Disk Usage

List Out Some Of The Performance Testing Tool?

HP Loader
HTTP Load
Proxy Sniffer
Rational Performance Tester
JMeter
Borland Silk Performer

Explain Performance Testing Life Cycle?

Step 1: System Analysis (Identification of critical transaction)

Virtual User Generator

Step 2: Creating Virtual User Scripts (Recording)

Step 3: Defining Users Behavior (Runtime setting)

LoadRunner Controller

Step 4: Creating Load Test Scenarios

Step 5: Running the Load Test Scenarios and Monitoring the Performance

LoadRunner Analysis

Step 6: Analyzing the Results

Mention The Steps Required In Jmeter To Create A Performance Test Plan?

To create a performance test plan in JMeter:

Add thread group
Add JMeter elements
Add Graph result
Run test & get the result

What Are The Different Components Of Loadrunner?

The major components of LoadRunner are:

VUGen- Records Vuser scripts that emulate the actions of real users.
Controller – Administrative center for creating, maintaining and executing load test scenarios. Assigns scenarios to Vusers and load generators, starts and stops loading tests.
Load Generator – An agent through which we can generate load
Analysis – Provides graphs and reports that summarize the system performance

Explain How You Can Execute Spike Testing In Jmeter?

In JMeter, spike testing can be done by using Synchronizing Timer.  The threads are jammed by synchronizing the timer until a specific number of threads have been blocked and then release at once, creating a large instantaneous load.

Explain What Is The Throughput In Performance Testing?

In performance testing, throughput is referred to the amount of data transported to the server in responds to the client request at a given period of time. It is calculated in terms of requests per second, calls per day, reports per year, hits per second, etc. Performance of application depends on throughput value, higher the value of throughput -higher the performance of the application.

Mention What Are The Phases For Automated Performance Testing?

Phases for automated performance testing includes:

Design or Planning
Build
Execution
Analyzing & Tuning

Mention What Is The Difference Between The Benchmark Testing And Baseline Testing?

Benchmark Testing: It is the method of comparing performance of your system performance against an industry standard that is set by other organization

Baseline Testing: It is the procedure of running a set of tests to capture performance information. When future change is made in the application, this information is used as a reference.

Mention What Is Concurrent User Hits In Load Testing?

In load testing, without any time difference when multiple users hit on the same event of an application under the load test is called a concurrent user hit.

Mention What Is The Benefit Of Load Runner On Testing Tools?

Benefit of LoadRunner testing tools is

Versatility
Test Results
Easy Integrations
Robust reports
Enterprise Package

Explain What Is Endurance Testing And Spike Testing?

Endurance Testing: It is one type of performance testing where the testing is conducted to evaluate the behavior of the system when a significant workload is given continuously

Spike Testing: It is also a type of performance testing that is performed to analyze the behavior of the system when the load is increased substantially.

Explain What Are The Common Mistakes Done In Performance Testing?

The common mistakes done in Performance Testing are

Direct jump to multi-user tests
Test results not validated
Unknown workload details
Too small run durations
Lacking long duration sustainability test
Confusion on definition of concurrent users
Data not populated sufficiently
Significant difference between test and production environment
Network bandwidth not simulated
Underestimating performance testing schedules
Incorrect extrapolation of pilots
 Inappropriate base-lining of configurations.

What Is The Reason Behind Performing Automated Load Testing?

Following drawbacks of manual Load Testing that leads to Automation load testing:

Difficult to measure the performance of the application accurately.
Difficult to do synchronization between the users.
Number of real time users are required to involve in Performance Testing
Difficult to analyze and identify the results & bottlenecks.
Increases the infrastructure cost

How Do You Identify The Performance Bottlenecks Situations?

Performance Bottlenecks can identify by monitoring the application against load and stress condition. To find bottleneck situation in performance testing we use Load Runner because provides different types of monitors like run-time monitor, web resource monitor, network delay monitor, firewall monitor, database server monitor, ERP server resources monitor and Java performance monitor. These monitors can help to us to determine the condition which causes increased response time of the application. The measurements of performance of the application are based on response time, throughput, hits per sec, network delay graphs, etc.

What Is Performance Tuning?

To improve the system performance we follow a mechanism, known as Performance tuning. To improve the systems performance there are two types of tuning performed:

Hardware tuning: Optimizing, adding or replacing the hardware components of the system and changes in the infrastructure level to improve the systems performance is called hardware tuning.
Software tuning: Identifying the software level bottlenecks by profiling the code, database etc. Fine tuning or modifying the software to fix the bottlenecks is called software tuning.



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