Load Runner interview Question & Answers-7

Q301. How to add multiple scripts against one group?

Answer:

Select the group

Click on vusers

Add new script for existing users or new users

Q302. On what basis you are deciding how many LGs required for test?

Answer:

Based on below parameters, you can decide how many LGs are required

1. Number of users

2. LG configuration

3. Script variables and size

4. Protocol type

5. Running vuser as a thread or process

Q303. What is memory footprint test?

Answer:

Testing with single user or 20 users and 50 users conducting how many

users it can sustain called memory footprint test.

Current version of LR will send the notification whenever it reaches the threshold point.

Q304. When you are going to run agent as a process or service?

Answer:

For all web based applications, run agent as a service.

For all client server applications or which applications are communicating with hardware of the machine (NTLM or windows based applications), run agent as a process.

Q305. Who will provide the ramp-up, ramp-down settings?

Answer:

No one will suggest to use specific ramp-up and ramp-down. As a performance tester, we have to derive the ramp-up time based on below parameters

1) Application type (web/client server)

2) Type of load balancer

Q306. If the controller crashes before collating the result, what is your approach to recover the file?

Answer:

If the controller crashes before collating the result, we can recover the result file.

Process:

• Go to load generator
• Select details
• Copy the path of the log
• Connect to LG through RDP
• Navigate to same path
• Copy “.eve” and “.log/.map” files
• Paste them into controller result path

Q307. How to calculate 90^th percentile?

Answer:

90 th percentile: 90 percent of the transactions are completing with in this limit.

Step1: Write all the response times in ascending order.

Step2: Take out 10% of values from below.

Step3: Which will be the highest value consider as 90% response time.

Q308. What is the process you are following to identify the bottleneck?

Answer:

Once the test got finished, I am going to compare derived statistics with expected statistics. If both are not comparable, then I will start the process to find out the root cause.

• Client side statistics analysis (analyzer, throughput, Hits per second, Response time).
• Server side statistics analysis (Hardware and OS level statistics).
• Application side statistics (Methods, I/O operations, DB, EJB, Packages etc..).
• Configuration setting analysis (Current limit, Connection limit, Thread limits..etc..).

Q309. What is the difference between absolute graph and relative graph?

Answer:

Absolute graph plots the graph based on the system time. Relative graph plots the graph based on elapsed time.

Q310. What are monitoring tools you used in your current project?

Answer:

For monitoring I using Perfon ,JVisual VM , Dynatrace .

Q311. What is extension of perfmon?

Answer:

.blg is the extension of Perfmon

Q312. What metrics we can monitor using JvisualVM?

Answer:

Using this we can monitor metrics like threads , packages , operations like since how much time those are running, and also we can take thread dump and memory dumps.

Q313. I wanna know the response time for a page with 1000 simultaneous users. What is your approach?

Answer:

Insert the rendezvous point in the script on the above the targeted request and enable rendezvous point in the controller with targeted no. of uses. After that if we executed the test . The test result will give the response time .

Q314.How to pass a value from one script to some other or with in the script?Using

Answer:

VTS we can share the data from either one script to another script or with in the script. (or)

Using data stagging also we can pass the variable or value from one script to another script.

Q315.What is garbage collection?

Answer:

When ever the objects are created dynamically at the same time we have to assign the memory to the objects. After some time we can see that there are two types of objects .Those are objects which are referred by the program and not referred by the program. Always we have to release the memory from the objects which are not referred by the program . This can be done by the garbage collector.

We can run this in two ways . One Is automatic and second is by manual.

Q316.Is it possible to give multiple ramp_ups ?

Answer:

Yes. Using real world scenario option we can create multiple ramp-ups and multiple ramp-downs.

Q317. In a page there are few links say 10 .For each and every reply links positions are changing. But every time you have to hit same link? What is your approach?

Answer:

First identify the link which we want to hit every time. After that correlate that particular link. So that for each and every reply even though the position of the links may vary the tool will hit on the same link.

Q318. I wanna generate the requests in the form of concurrent groups ? How to achieve this?

Answer:

To achieve this we have to record the script in URL mode.

Q319.What is legend ? What is the use of that?

Answer:

Legend will instruct that which colour instructs which measurement.

Q320. What is impact on the response time suppose if I included the think time in inside of the transaction?

Answer:

The impact definitely will be there on the response time because we kept the think time inside of the transaction so that including the think time response time will be measured. So the response time will increase.

Q321. By mistake I included the think time in inside of the transaction? What I have to do rectify that problem?

Answer:

In two ways we can do this. The best way is while analyzing the results in the analyzer we have properties option under that choose filter and select don't include think time.

Otherwise the alternative option is goto vugen script , paste the think-time outside of transaction and again execute the test. This process will take the more time.

Q322. How to gather the requirements ?If the application is green field application?

Answer:

If the application is completely new at that we have to keep in touch with the business analyst(BA).

Q323. How to gather the requirements ?If we have a competitor in the market ?

Answer:

If we have the competitor in the market at the time using traffic utility tools we will gather the competitor statistics and will use the same statistics for our test. Like identify NFR’s in terms of peak hours, half peak hours, no. of users, no. of page views from which location they are accessing the application, which pages mostly access by end users & what are the expected response times for every page.

Q324. What is response time?

Answer:

The round trip of the request is called the response time. In general we will measure the response times to estimate the application performance under the load.

Q325. What is IP spoofing?

Answer:

Masking the original IP address and generating multiple IP addresses is known as IP spoofing.

Q326.What is Entry Criteria?

Answer:

Whenever the Pre-requisites are satisfied that is called Entry Criteria.

Q327.What is Exit Criteria?

Answer:

Whenever derived statistics are meeting expected statistics that can be considered as Exit Criteria.

Q328.When we have to start Performance testing?

Answer:

1. The build should be released and stable
2. The build should be functionally satisfy.
3. The test data should be ready.
4. The test environment setup should be done.

Q329.What are inputs and outputs of Workload model?

Answer:

Input: Use cases, types of testing, number of users

Output: Pacing, think time and transaction mix

Q330.What is the use of save-offset argument ?

Answer:

Using save-offset we can ignore few number of characters from the dynamic value.

Q331.In a scenario there is a drop down in that drop down for each and every reply the position of the elements in the drop down are changing. But Every time I wanna capture same element/value. What is your approach to achieve this?

Answer:

To achieve this we have to use real frame ID .

[ Write Web_reg_save_param correlation function with the arguments Param name , LB , RB, real frame ID .]

Q332.Tell me few algorithm names which can be used to distribute the loads to LGs?

Answer:

Few of the algorithms which we can use to distribute the load to the LG(load generate)

1. round robin

2. IP sticky

3. Low load

4. least connections.

Q333.What is the significance of LG in performance testing?

Answer:

Using LG we can generate huge amount of load on the targeted application in order to know the application behavior.

Q334.On what basis you are going to select the LG?

Answer:

Using memory foot print test I will choose the LG. Based on the number of users and configuration of Load generates we can select the number of load generators how many are required to apply the load on the application.

Q335.How to handle OTP(one time password)?

Answer:

To handle OTP we have few solutions

sol 1: Tell the developer to use static otp.

Sol 2: disable the otp feature for testing.

Sol 3: ask the java file which is causing to generate the OTP and add that file and call that file when ever it is necessary.

Q336.If the dynamic value is generated buy a Java Script file & the same value is not available in the response?

Answer:

Speak with the developer understand how the dynamic value is generating. If it is generated by Java Script file usually at Client side.

Take the Java Script which is creating a “.js” file in extra files and call the function whenever we like to generate the dynamic value.

Q337.To execute a test I have 1000 data points but I wanna instruct the user is that the user has to pick the data points from 50^th data point? What is your approach to achieve this?

Answer:

Using parameter properties options i.e. using first data line I will enter the data point number as 50 . So first 49 data points will be dis-appear. Then automatically the user will start to pick the 50^th data point.

Q338.For the first time you replied a script . Script is failing ? What is the reason (even though there is no chance to generate dynamic values )

Answer:

Because of headers missing also some times the script may fail.

So compare reply time headers with recording time headers .If you found ant header is missing then add the header to the script using the function

web_add_header();

Q339.How to generate Date and time ?

Answer:

Using the date and time type parameterization we can generate date & time.

Q340.How many maximum data points we can load in a csv file ?

Answer:

36,000 data points

Q341.What is the use of the block concept in parameter properties?

Answer:

This concept is only available for unique each iteration and unique each occurrence.

When ever we wanna divide the data points into blocks and assign the same to the users at that time we will use this.

We can divide the data points into blocks in two ways .

1. manually: If we choose this option , manually we have to divide the data points into blocks and enter the same

2. Automatically : controller it self divides and allocate the same to the each and every user.

Q342.Which is the best process ? Either running user as thread or process ? Why?

Answer:

Running user a thread is best process because running user as thread we can assign more users than running user as a process. And also if we run the user as thread , the user will utilize less memory.

Q343.How to know that how many times a text is present in the response?

Answer:

To very whether a particular text is present in the response or not for that we will use web_reg_find () function . In this function if we use save-count argument that will tell you that how many times that text is present in the response.

Syntax:

web_reg_find (“text”,”savecount=count”,LAST);

Save count let you know how many times a particular text is present in the response.

Q344.How to assign an integer value to load runner variable?

Answer:

Directly we cant assign an integer value to load runner variable because all the variables in load runner are strings. So convert integer to string using I to a function. Now converted value is string so we can use that directly where ever it is necessary.

Syntax:

int y=100;

Itoa(y,girmiti,10) ; //output= girmiti = 100

lr_save_string(girmiti,”final”); // output= final=100

where ever 100 we wanna use there we can use final.

Q345.What is the use of lr_set_debug_message () function?

Answer:

Using this function we can set the debug message to the request at a particular level.

Q346.How many ways we can debug an error?

Answer:

Sol 1: Using lr_set_debug_message () function

sol 2: using toggle point or breaking point

sol 3 : executing script in step by step

Q347.what is the use of the function lr_save_int()?

Answer:

Using this function we can assigns integer value in to LR variable.

this also used instead of itoa function.

lr_save_string(y,“girmiti”);

Here integer y will be assigned to girmiti

Q348.What is difference between lr_error_message () and lr_output_message()?

Answer:

Using lr_error_message () function we can send the error message to the controller message area but using lr_output_message() we didn't.

Q349.What is your approach to The scenario, the user has to login to application, book and cancel tickets for multiple times for Every iteration has to perform login and log off?

Answer:

We have to record all into action().

Q350.How to create multiple actions?

Answer:

Sol 1: While recording itself we can create multiple actions.

Sol 2: We can create new action using create new action option.