Following are the Performance Testing Interview Questions Set #11.
Q. 51 What are the Challenges that you face during scripting?
Ans: Challenges faced on the scripting:
- Using the file functions in the scripting of Vugen
- Using of the randomization techniques in scripting
- Handling the correlation for the .Net and java applications like view state, even validation, session id etc.
Q. 52 What is the memory leak? How do you find the memory leak?
Ans: Memory leaks are class-level bugs in any application, in which the application fails to release memory when no longer needed. Over the duration of time, memory leaks affect the performance of both the particular application as well as the operating system. A large leak might result in unacceptable response times due to excessive paging.
Q. 53 What is the heap size? How do you analyze the heap size?
Ans: When a Java program starts, Java Virtual Machine gets some memory from the Operating System. Java Virtual Machine or JVM uses this memory for all its needs and part of this memory is called java heap memory. When we get the errors such as out-of-memory exceptions then we need to analyze the heap size by taking the heap dump for that particular application.
- The maximum heap size is represented in the parameter Xmx.
- The minimum heap size is represented in the parameter Xms.
Q. 54 What is Network latency?
Ans: Network Latency is the time taken by the channel to transfer the data from one end to another. Network Latency adds a delay in the overall response time.
Q. 55 What is Network Performance?
Ans: Network Performance is typically measured in terms of the success of IP forwarding, the time and variation of packets of data transferring from source IP to destination IP successfully with the proper acknowledgement details.
“A large leak might result in unacceptable response times due to excessive paging.” Paging happens at the OS level, how is that related to memory leak of applications? Can you kindly explain?
A slight correction in your sentence, memory leakage occurs in memory irrespective of OS level. Any un-tuned program causing high paging which leads to memory leakage.
If the application under test leaks memory then it will, over time, require page faults to continue operation (paging). The memory leak has a direct correlation to the application paging memory.