Q: What is Endurance Testing & Spike Testing?
- Endurance Testing – It is a 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 a type of performance testing that is performed to analyze the behavior of the system when the load is increased substantially.
Q: What are the top 3 Response KPIs for Performance Testing?
- Average response time – time to first byte or last byte
- Peak response time – tells your longest cycle
- Error rate – percentage of problems compared to all requests
Q: What Is Distributed Load Testing?
- Distributed load testing is the process of simulating a very high workload of an enormous number of users using multiple systems. As a single system cannot generate a large number of threads (users), multiple systems are used for load testing. It helps to distribute the tests and the load.
Q: What is the difference between front-end and back-end performance testing? Which one is more important?
- Front-end performance is concerned with how quickly text, images, and other page elements are displayed on a user’s browser page.
- Back-end performance is concerned with how quickly these elements are processed by the site’s servers and sent to the user’s machine upon request. Remember: Front-end performance is the part of the iceberg above the water line, and back-end performance is everything underneath that you can’t see.
- Both are important because they can both determine whether a user continues to use your application.
Q: You run a load test against a server with 4GB RAM and the results show an average response time of 30 seconds for a particular request. The production server has been allocated 8GB RAM. What would you expect the average response time of the same request to be in production given the same load?
- While you may be tempted to answer that the response time would be halved to 15 seconds, reality is rarely that convenient. Response times are a factor of so much more than memory. Things like CPU utilisation, network throughput, latency, load balancing configuration, and just application logic are always going to influence load tests. You can’t assume a linear progression in response time just because you’ve upgraded one part of the hardware. This is why it’s important to load test against an environment that is as production-like as possible.
Q: After running a load test, the results show that 300 transactions were executed with a PASSED status and returning responses of HTTP 200. However, the DBA tells you that there were no records written to the database as a result of the transactions. How would you troubleshoot this?
- Its important to add various counters and monitors DB servers too. + Its very important to add assertions to make sure a request is successful. In the above mentioned case, it can be a bug or it can be due to poor scripting too. Adding right assertions, and counters will help in troubleshooting.
Q: Have you heard about New Relic or Datadog?
- These are the monitoring tools.
Q: What are the benefits of monitoring tools like – New Relic , Datadog, etc?
- Monitoring tools lets you monitor all your infrastructure in one place by creating monitors that will continuously check the health of your infrastructure. Access everything you need in one dashboard and see the data as it comes in straight from your systems.
- Establishes end-to-end application performance and stability, by identifying and leveraging preventative tasks on-demand.
- Creation of active metrics associated with data response times, CPU usage, load-balance alarms, exceptions etc.
Stay Tuned For Part 2..