30+ Performance Tester Interview Questions and Answers

Answers to questions related to Performance Testing using JMeter

• Assertion in JMeter is used to validate the response of a request

• JMeter supports various protocols like HTTP, FTP, JDBC, etc.

• Hits per second is the number of requests sent to the server in a second

• Hits per second may become constant due to server limitations or network issues

• Sync testing involves waiting for a response before sending the next request, while async testing sends requests without waiting for a respo...read more

Yes

• During load testing of a web application, memory usage gradually increased over time

• Identified the memory leak by monitoring memory consumption using performance testing tools

• Investigated the code and found a section where objects were not being properly released

• Fixed the memory leak by implementing proper object disposal and memory management techniques

Memory leak is a software issue where allocated memory is not released, leading to memory consumption and performance degradation.

• Memory leak occurs when a program fails to deallocate memory that is no longer needed.

• It can happen due to programming errors like not freeing allocated memory or losing references to it.

• Memory leaks can cause the program to consume excessive memory, leading to performance issues and crashes.

• To handle memory leaks, tools like profilers can be used ...read more

Run time setting parameters are values that can be set during test execution to control the behavior of the test.

• Run time setting parameters are used to modify the behavior of the test during execution.

• They can be used to simulate different user loads, network conditions, and other variables.

• Examples include setting the number of virtual users, the duration of the test, and the think time between requests.

Think time is the time taken by a user to think and perform an action, while pacing is the time interval between two consecutive user actions.

• Think time is the time taken by a user to read and understand the content on the screen before performing an action.

• Pacing is the time interval between two consecutive user actions, which is used to simulate real-world user behavior.

• Think time is used to simulate the time taken by a user to think and perform an action, while pacing is u...read more

Performance engineering is the process of designing, implementing, and optimizing systems to meet performance requirements.

• Performance engineering involves analyzing and understanding performance requirements

• It includes designing and implementing systems to meet those requirements

• Optimizing systems through load testing, stress testing, and performance tuning

• Performance engineering also involves monitoring and analyzing system performance in production

• Examples of performance e...read more

The challenge I am facing while scripting is identifying and handling dynamic elements.

• Dynamic elements such as timestamps and session IDs require unique handling

• Identifying and correlating dynamic values across multiple requests can be time-consuming

• Using regular expressions and functions can help in handling dynamic elements

Test plan is a document that outlines the testing strategy while RTM is a document that maps requirements to test cases.

• Test plan outlines the scope, objectives, resources, and schedule of testing.

• RTM maps the requirements to test cases to ensure all requirements are covered.

• Test plan is created before testing begins while RTM is created during testing.

• Test plan is a high-level document while RTM is a detailed document.

• Test plan is used to guide the testing process while RTM ...read more

Performance testing focuses on evaluating the speed, responsiveness, and stability of a system, while performance engineering involves designing and optimizing the system for optimal performance.

• Performance testing is the process of testing the performance characteristics of a system under specific conditions.

• Performance engineering is the proactive approach of designing, building, and optimizing a system for optimal performance.

• Performance testing measures the speed, respons...read more

Parameters in result table are the values that are measured during performance testing.

• Parameters can include response time, throughput, error rate, and resource utilization.

• These values are used to analyze the performance of the system under test.

• They can be compared against performance requirements or industry benchmarks.

• Parameter values can be displayed in graphs or charts for easy analysis.

• Examples of parameter values include average response time, maximum throughput, and...read more

Performance bottleneck can occur in various areas of an application.

• Database queries and indexing

• Network latency and bandwidth

• CPU and memory usage

• Code inefficiencies and poor algorithms

• Third-party integrations

• Hardware limitations

• User load and concurrency

• Application architecture

• Caching and session management

• Security measures

• External factors such as weather or power outages

Agile is an iterative and incremental approach to software development that emphasizes flexibility and customer satisfaction.

• Agile involves breaking down the project into smaller, manageable chunks called sprints.

• Each sprint involves planning, designing, coding, testing, and reviewing the work done.

• The team works closely with the customer to ensure that the product meets their needs.

• Agile encourages collaboration, communication, and continuous improvement.

• Popular Agile method...read more

Use JMeter to send post data from a file

• Use CSV Data Set Config to read data from a file

• Add HTTP Request sampler to send post data

• Reference variables from CSV file in HTTP Request body

I have strong technical skills in performance testing through hands-on experience with various tools and technologies.

• Proficient in using performance testing tools such as JMeter, LoadRunner, and Gatling

• Experience in designing and executing performance test scenarios to identify bottlenecks and optimize system performance

• Knowledge of performance monitoring tools like New Relic and AppDynamics

• Ability to analyze test results and provide recommendations for performance improveme...read more

My expected CTC is negotiable based on the job responsibilities, company size, and industry standards.

• My expected CTC is based on my experience, skills, and qualifications.

• I have researched the market rates for Performance Testers in similar roles and industries.

• I am open to discussing the compensation package and benefits offered by the company.

• I believe in a fair and competitive salary that aligns with my expertise and contributions.

• I am looking for a package that recognize...read more

Pacing in performance testing refers to controlling the rate at which virtual users execute transactions to simulate real-world user behavior.

• Pacing helps in simulating realistic user behavior by controlling the rate of transactions executed by virtual users.

• It is calculated by dividing the total test duration by the number of transactions to be executed.

• For example, if a test is scheduled to run for 1 hour and 600 transactions need to be executed, the pacing would be 1 trans...read more

CPU bottleneck can be handled by optimizing code, upgrading hardware, and load balancing.

• Identify the root cause of the CPU bottleneck through performance monitoring tools.

• Optimize the code by identifying and fixing inefficient algorithms or resource-intensive operations.

• Upgrade hardware by adding more powerful CPUs or increasing the number of cores.

• Implement load balancing techniques to distribute the workload across multiple CPUs or servers.

• Consider vertical scaling by upgr...read more

Load balancing is the process of distributing network traffic across multiple servers to optimize performance and prevent overload.

• Load balancing improves scalability and availability of applications.

• It ensures that no single server is overwhelmed with traffic.

• Load balancers can use various algorithms to distribute traffic, such as round-robin, least connections, or IP hash.

• Examples of load balancing technologies include hardware load balancers, software load balancers, and c...read more

JVM is a virtual machine that executes Java bytecode. It manages memory, provides runtime environment, and enables platform independence.

• JVM stands for Java Virtual Machine.

• It is responsible for interpreting and executing Java bytecode.

• JVM manages memory allocation and garbage collection.

• It provides a runtime environment for Java applications.

• JVM enables platform independence by abstracting the underlying hardware and operating system.

• JVM includes components like class loader...read more

Distributed load testing involves simulating multiple virtual users from different locations to test the performance of a system under heavy load.

• Involves simulating virtual users from different locations

• Tests the performance of a system under heavy load

• Helps identify bottlenecks and performance issues

• Commonly used in web applications and APIs

Performance testing is a type of testing to ensure software applications perform well under expected workload.

• Performance testing evaluates the speed, responsiveness, and stability of an application under various load conditions.

• It helps identify bottlenecks, performance issues, and areas for improvement in the application.

• Types of performance testing include load testing, stress testing, and scalability testing.

• Tools like JMeter, LoadRunner, and Gatling are commonly used for...read more

Ramp up and ramp down are performance testing terms referring to gradually increasing or decreasing the load on a system.

• Ramp up is the process of gradually increasing the number of virtual users accessing a system over a period of time.

• Ramp down is the opposite process of gradually decreasing the number of virtual users accessing a system over a period of time.

• Ramp up and ramp down help in simulating real-world scenarios where the load on a system gradually increases or decr...read more

JMeter supports various protocols for performance testing including HTTP, FTP, JDBC, SOAP, and more.

• HTTP protocol is commonly used for web applications

• FTP protocol is used for file transfer testing

• JDBC protocol is used for testing database connections

• SOAP protocol is used for testing web services

Correlation is a statistical measure that describes the strength and direction of a relationship between two variables.

• Correlation values range from -1 to 1, with 0 indicating no correlation, 1 indicating a perfect positive correlation, and -1 indicating a perfect negative correlation.

• Positive correlation means that as one variable increases, the other variable also increases. Negative correlation means that as one variable increases, the other variable decreases.

• For example,...read more

Performance testing involves testing the speed, stability, and scalability of a software application under various conditions.

• Identify performance testing objectives and requirements

• Create test scenarios and scripts

• Execute tests and collect performance metrics

• Analyze results and identify bottlenecks

• Report findings and recommend improvements

Performance threads are concurrent virtual users that simulate real-world user behavior.

• Performance threads are used in load testing to simulate multiple users accessing a system simultaneously.

• Each thread represents a virtual user and performs a specific set of actions on the system.

• Threads can be configured with different parameters such as ramp-up time, duration, and number of iterations.

• Performance threads can help identify bottlenecks and performance issues in the system...read more

Performance testing is the process of determining the speed, responsiveness, and stability of a system under a specific workload.

• Performance testing helps identify bottlenecks and areas for improvement in a system.

• It involves simulating real-world scenarios to measure the system's performance.

• Common types of performance testing include load testing, stress testing, and scalability testing.

• Examples of performance testing tools include JMeter, LoadRunner, and Gatling.

I have experience working with various performance testing tools.

• JMeter

• LoadRunner

• Gatling

• BlazeMeter

Loadrunner components include Virtual User Generator, Controller, Load Generator, Analysis

• Virtual User Generator (VUGen) - used to create and edit scripts

• Controller - used to organize, execute, and monitor tests

• Load Generator - used to simulate virtual users

• Analysis - used to analyze test results

CPU controlling limits refer to the maximum amount of CPU resources that can be allocated to a process or application.

• CPU controlling limits are important for ensuring that a single process or application does not consume all available CPU resources, which can lead to system instability and poor performance.

• These limits can be set at the operating system level or within specific applications.

• Examples of CPU controlling limits include CPU quotas, CPU shares, and CPU affinity s...read more

Scripting test in JMeter involves creating test scripts to simulate user actions and interactions with the application under test.

• Use JMeter's recording feature to create test scripts by recording user interactions with the application.

• Manually create test scripts by adding samplers, listeners, and other elements to simulate different user actions.

• Parameterize test scripts to simulate multiple users with different data inputs.

• Use assertions to validate the responses from the ...read more