1)
Which
protocols are supported by Loadrunner ?
As of Loadrunner 9.5 following protocols are supported. This
will increase with future releases. The interviewer is not looking for you to
name all but a few (say 5-7 protocols).
Application Deployment Solution: For the Citrix
protocol.
Client/Server: For DB2 CLI, DNS, MS SQL, ODBC, Oracle (2-tier), Sybase Ctlib, Sybase Dblib, and Windows Sockets protocols. Custom: For C templates, Visual Basic templates, Java templates, Javascript and VBscript type scripts. Distributed Components: For COM/DCOM, Corba-Java, and Rmi -Java protocols. E-business: For FTP, LDAP, Palm, Web (HTTP/HTML), Web Services, and the dual Web/Winsocket protocols. Enterprise Java Beans: For EJB Testing and Rmi-Java protocols. ERP/CRM: For Baan, Oracle NCA, Peoplesoft-Tuxedo, Peoplesoft 8, SAPGUI, SAP-Web, and Siebel (Siebel-DB2CLI, Siebel-MSSQL, Siebel-Web, and Siebel-Oracle) protocols. Legacy: For Terminal Emulation (RTE). Mailing Services: Internet Messaging (IMAP), MS Exchange (MAPI), POP3, and SMTP. Middleware: Jacada and Tuxedo (6, 7) protocols. Streaming: For MediaPlayer and RealPlayer protocols. |
2) Which
components have you used in Loadrunner ?
Vuser generator - For
generating Scripts
Controller - For creating and executing scenarios
Analyzer - To analyze results
3) What is load
runner Agent.
Agent is interface between host machine and controller
4) What is the process for developing a Vuser
Script ?
There are 4 steps for developing a vuser script.
1-Record the Vuser Script .
2-Playback / Enhance the recorded vuser script.
3- Define the various run-time settings & check
1-Record the Vuser Script .
2-Playback / Enhance the recorded vuser script.
3- Define the various run-time settings & check
4- Incorporate the script in a Loadrunner scenario
5) How many
VUsers are required for load testing ?
The number of VUsers required depends on your system under test
, network configurations , hardware settings, memory, operating system,
software applications objective of performance test. There can not be any
generic value for Vuser.
6) What is the
difference in running the Vuser as a process and as a thread? Which is more
advantageous way of running Vuser?
When Vuser is run as a process the same driver program is loaded
into memory for each Vuser. This will take a large amount of memory and will
limit the number of Vusers you can run on a single generator
When Vuser is run as a thread, only one instance of driver
program is shared by given number of Vusers. You can run more number of
Vusers on a single generator using the multi-threading mode.
7) What is the
significance of "Vuser-init "?
Vuser-init records the pre-operations also called the
initialization operations before the actual application is run.
8) What is
extended log?
An extended log will store information such as data returned by
server and advanced trace, parameter substitution and much other information
depending on the options you select in run-time settings.
9) Why do you
create parameter?
To create a parameter you will replace the hard coded value
within the script and replace it with a parameter. This allows a single Vuser
to be run many times, and to use different data on each run. It helps in
stimulating more real life server demand as it prevents server from caching
results.
10) How will you
divide your script into multiple Actions? Why?
I will divide the script into Actions based on the
functionality. For example, Once Action for Logining into Application, another
Action for booking and so on.
Actions increase code reusability, reduce maintenance time and
hence, decrease costs.
11) How can you
set the number of Vusers in Loadrunner ?
You can set the number of Vusers in the controller section while
creating your scenarios. Many other advanced options like ramp-up, ramp-down of
Vusers are also available in the Controller section.
12) What
are monitors?
Monitors are used to "monitor" performance
bottlenecks. They are used in Controller section of Load Runner
13) What
are the types of check points is available in LoadRunner?
Loadrunner provides two types of check points
a) Image Checkpoints : This checkpoint will verify the presence
of an image on a page during run-time
b) Text Checkpoint : This checkpoint will verify the presence of
a text-string on a page during run-time
Both of the above checkpoints can be added in Vugen.
14) What
kind of problem we can face regarding hardware, software, network and
memory bottleneck during the performance test?
The possible issues amongst others could be -
1. Lack of Hardware
2. Memory Leakage
3. Network related issues.
4. Applicaton/Software error
15) What
would be your recommendation to improve performance measure?
Fine Tuning of network, database, and app and web server is
recommended.
At the network level try to optimize the latency and bandwidth.
At database level, verify all indexes and sequences by running
profilers. You may also optimize your database queries.
At the App server level, run profilers for finding the memory
leaks in the application
At the web server level you can use monitors and optimize the
throughput and other related metrics of the server.
16) What is
Rendezvous point?
Rendezvous point is Synchronization/Wait point .
Rendezvous points instruct Vusers to wait during test execution for multiple
Vusers to arrive at a certain point, in order that they may simultaneously
perform a task.
The significance of this is to emulate some heavy load only to
particular portion of the scenario and test the behavior of the application.
17) What is
Correlation?
Correlation is used to obtain data which is unique for each run
of your test script (ex: session ids). While recording, these dynamic values
are hard-coded in your script causing the script to fail during playback.
Correlation is a technique where dynamic values are not hard-coded in your
script but are extracted at run-time to avoid failure.
18) What is
Manual Correlation?
Its correlation technique which uses function
Web_reg_save_param() to identify dynamic values in your script. It is
important that your playback your script to verify that correlation is done
successfully.
19) How do
you identify the performance bottlenecks?
Performance Bottlenecks can be detected by using monitors.
These monitors might be application server monitors, web server
monitors, database server monitors and network monitors.
They help in finding out the troubled area in our scenario which
causes increased response time.
The measurements made are usually performance response time,
throughput, hits/sec, network delay graphs, etc
20)
Which function is used to end a nested transaction ?
The function is - lr_end_sub_transaction
21)
What is the difference between transaction and transaction instance in
loadrunner ?
A transaction is used to measure time between executions of
certain statements
A transaction instance is used for performance analysis
22)
While the script is running we find some values that may be need to be
correlated? Is it possible to do manual correlation for those values?
NO. Its not possible to do correlation when script is running
but you can make changes once script has stopped.
23)
What is Elapsed Time in Load Runner?
Elapsed time designates how much time has passed since the
launch of the current event and is measured differently for different screens
as given below -
In Scenario Status Window - Elapsed time is measured from the
moment you hit "Start Scenario" or " Initialize/Run Vuser?"
button.
In "Vuser" window elapsed time is measured form the
moment Vuser enters "running" state.
24)
Does caching have a negative effect on your load testing results ?
Yes. Caching has a negative effect. Cache is temporary memory
which stores your browsing history. When you visit a page for the SECOND time ,
the time required to load the page will be less than that required to load the
page for your first visit since much of the information required to load the
page is grabbed from the cache instead of the server. This will effect the
response times in your test. Hence, it is recommended to turn-off caching.
25)
What is the difference between Overlay graph and Correlate graph?
Overlay
Graph: It will overlay the content of two graphs that shares a common
x-axis
Correlate
Graph: It
will Plot the Y-axis of two graphs against each other.
26)
What is the difference between lr_error_message and lr_debug _message?
lr_error_message - Sends a error message to the LoadRunner
Controller's Output window
lr_debug _message - Sends a debug message to the LoadRunner
Controller's Output window
27)
What is the difference between load , performance testing ?
The objective of performance testing is to check whether an
application loads/updates within stipulate time limit (say 2 seconds). It
uses metrics like response time , Requests per second. It is carried out under
production - like load conditions.
The objective of load testing is to check scalability of the
system. For example, finding out the maximum number of users supported by the
system within certain specifications.
28)
You have created several Auto Correlation rules. A new tester on your
team is preparing to record a group of scripts on the same application on his
workstation. What can you do to provide the tester with the correlation rules?
I would export the Auto Correlation rules to a .cor file,
and then have the new team member import the .cor file into his Auto
Correlation rules
29)
You want to emulate a call center for an airline. All representatives login in
the morning, perform their business processes, and log out at night. In one
day, a representative will Create 40 flight reservations, Modify 10 flight
reservations, and Search for 20 flight reservations. A representative cannot
perform a Modify without performing a Search first. How would you design the
run logic ?
Create - 67% Search - 16% Block0 - 17% Search Modify
30)
Where should you add a web_reg_save_param function to a script?
Before the step that retrieves the dynamic value
31)
You want to have each step in your script measured as a transaction in the
Controller and not shown in the Replay Log in VuGen. How can you accomplish
this?
This can be done by enabling the automatic transaction in
the Run-time settings
32)
Which web protocol recording level generates the web_submit_form function?
The URL protocol generates this function.
