Here are some of the actual interview questions for a QA tester and how the person answered them. I thought this will give us some idea on what kind of questions to expect and how to answer them.
1. Can you tell me about yourself?
Answer: In my QA career, I have been working on various system platforms and operating systems like Windows 95, Windows 2000, Windows XP and UNIX. I have tested applications developed in Java, C++, Visual Basic and so on. I have tested Web-based applications as well as client server applications.
As a QA person, I have written Test Plans, Test Cases, attended walkthrough meetings with the Business Analysts, Project Managers, Business Managers and QA Leads. I have attended requirement review meetings and provided feedback to the Business Analysts. I have worked in different databases like Oracle and DB2, wrote SQL queries to retrieve data from the database. As far as different types of testing is concerned, I have performed Smoke Testing, Functional Testing, Backend Testing, Black Box Testing, Integration Testing, Regression Testing and UAT (User Acceptance Testing) Testing. I have participated in Load Testing and Stress Testing.
I have written defects as they are found using ClearQuest and TestDirector. Once the defects were fixed, retested them and if the passed, closed them. If the defects were not fixed, then reopened them. I have also attended the defect assessment meetings as necessary.
In the meantime, a continuous interaction with developers was necessary.
This is pretty much what I have been doing as a QA person.
2. What did you do in your last project?
Answer: In my last project, the application was a web-based application developed in Java platform. As a QA Person, I wrote Test Plans from the requirement documents and Use Cases. I performed Smoke Testing, Functional Testing, Backend Testing, Black Box Testing, Integration Testing, Regression Testing and UAT (User Acceptance Testing). I have participated in Load Testing and Stress Testing. I attended several walkthrough meetings for requirement reviews and provided feedback to the Business Analysts. Mostly, I was in the backend testing, which required writing SQL queries directly to the database.
Besides these, I wrote defects using ClearQuest. Once the defects were fixed, retested them and if the passed, closed them. If the defects were not fixed, then reopened them.
3. Have you written Test Plan? What is a Test Plan? What does it include?
Answer: Yes.
What is a Test Plan?
Answer: A Test Plan is a document that describes the scope, approach, resources, and schedule of intended testing activities. It identifies test items, the features to be tested, the testing tasks and who will do each task (roles and responsibilities) and any risks and its solutions.
What does it include?
Answer: A Test Plan includes Heading, Revision History, Table of Contents, Introduction, Scope, Approach, Overview, different types of testing that will be carried out, what software and hardware will be required, issues, risks, assumptions and sign off section.
4. Have you written Test Cases? Answer: Yes.
What is a Test Case? What does it include?
Answer: A Test Case is a document that describes step-by-step process how to test the application. A Test Case includes Test Case ID, Steps Description, Expected Output, Actual Output, Pass/Fail, and Remarks. (Remember, this is NOT a part of Test Plan. It is a separate document written using Excel. In some companies, they use Rational TestManager or TestDirector. But for companies, who do not have these tools, use Excel sheet. In t he example below, it is in the Excel sheet)
Did you use any tools to write Test Cases?
Answer: Yes. I have used TestDirector (now called QualityCenter) and Rational TestManager to write Test Cases. However, in most of the companies, I used Excel sheet.
How many Test Cases did you write in your last project?
Answer: I wrote about 1100 Test Cases in my last project. (The reasonable number of Test Cases varies from 500 to thousands. The number 1100 test cases can be completed in 6-month project duration).
What document did you refer to write the Test Cases?
Answer: Requirement document. (NOTE: It can also be Use Cases, or Design Document. It depends company to company. In some company, they use Use Cases. In some companies, they use Requirement Documents and in companies, they use Design Document. However, in practical scenario, most of the companies have requirement document at least).
5. Did you have a situation where you did not have any documents (no requirement document, no Use Cases, or no Design Document) and you had to write the Test Cases? How did you write the Test Cases in this situation?
Answer: Yes. I have been to that kind of scenarios several times. There were companies where they had no documents at all. In that case, I had to discuss the application scenario and functionalities with the Business Analysts or developer. On the basis of that discussion, I prepared a document in consultation with Business Analysts and Developers and then started writing Plans and Test Cases.
6. What you worked with Use Cases before?
Answer: Yes. I have written Test Cases using Use Cases.
Can you tell me what a Use Case is?
Answer: A use case is a document that describes the user action and system response for a particular functionality.
7. What is SDLC (Software Development Life Cycle)?
Answer: SDLC (Software Development Life Cycle) is the process of developing software through business needs, analysis, design, implementation and maintenance. Software has to go through various phases before it is born which are as follows:
(i)Generating a Concept – A concept comes from the users of the software. For example, a Pizza Hut may need software to sell pizza. An Indian store may need software to sell its newly arrived movies or grocery. The owner of the company feels that he needs software that would help him in tracking his expenses and income as well as enhance the selling process. This is how the concept is generated. The owner will specifically tell the software company what kind of software he would need. In other words, he will specify his requirements.
(ii) Requirements analysis – After the owner (user) knows his requirements, then it is given to a software team (company) who will analyze the requirement and prepare requirement document that will explain every functionality that are needed by the owner. The requirement document will be the main document for developers, testers and database administrators. In other words, this is the main document that will be referred by everyone. After the requirement documents, other detailed documents many be needed. For example, the architectural design which is a blueprint for the design with the necessary specifications for the hardware, software, people and data resources.
(iii) Development: After the detailed requirement documents (some companies have design documents instead of requirement documents), the developers start writing their code (program) for their modules. On the other hand, the testers in the QA (Quality Assurance) Department start writing Test Plans (one module=1 test plan), test cases and get ready for testing.
(iv) Testing: Once the code (programs) are ready, they are compiled together and to make a build. This build is now tested by the software testers (QA Testers)
(v) Production: After testing, the application (software) goes into production (meaning, it will be handed over to the owner).
(vi) End: And one day, the owner will have say bye to the software either because the business grows and this software does not meet the demand or for some reason, the he does not need the software. That’s the end of it.
8. What is Business Requirement Document (BRD)?
Answer: It is a document that describes the details of the application functionalities which is required by the user. This document is written by the Business Analysts.
9. What is Business Design Document?
Answer: It is the document that describes the application functionalities of the user in detail. This document has the further details of the Business Requirement Document. This is a very crucial step in Software Development Life Cycle (SDLC). Sometimes the Business Requirement Document and Business Design Document can be lumped together to make only one Business Requirement Document.
10. What is a Module?
Answer: A ‘Module’ is a software component that has a specific task. It can be a ‘link’, which can go inside to its component detail. (This is NOT a very common question for the interview. This is just for your knowledge, if you don’t know what a module is)
http://www.portnov.com/data/Prakash_Nepal_interview_questions.html
Thursday, February 24, 2011
Tuesday, February 22, 2011
Web Service Interview Questions and Answers
What is a Web service?
Many people and companies have debated the exact definition of Web services. At a minimum, however, a Web service is any piece of software that makes itself available over the Internet and uses a standardized XML messaging system.
XML is used to encode all communications to a Web service. For example, a client invokes a Web service by sending an XML message, then waits for a corresponding XML response. Because all communication is in XML, Web services are not tied to any one operating system or programming language--Java can talk with Perl; Windows applications can talk with Unix applications.
Beyond this basic definition, a Web service may also have two additional (and desirable) properties:
First, a Web service can have a public interface, defined in a common XML grammar. The interface describes all the methods available to clients and specifies the signature for each method. Currently, interface definition is accomplished via the Web Service Description Language (WSDL). (See FAQ number 7.)
Second, if you create a Web service, there should be some relatively simple mechanism for you to publish this fact. Likewise, there should be some simple mechanism for interested parties to locate the service and locate its public interface. The most prominent directory of Web services is currently available via UDDI, or Universal Description, Discovery, and Integration. (See FAQ number 8.)
Web services currently run a wide gamut from news syndication and stock-market data to weather reports and package-tracking systems. For a quick look at the range of Web services currently available, check out the XMethods directory of Web services.
What is new about Web services?
People have been using Remote Procedure Calls (RPC) for some time now, and they long ago discovered how to send such calls over HTTP.
So, what is really new about Web services? The answer is XML.
XML lies at the core of Web services, and provides a common language for describing Remote Procedure Calls, Web services, and Web service directories.
Prior to XML, one could share data among different applications, but XML makes this so much easier to do. In the same vein, one can share services and code without Web services, but XML makes it easier to do these as well.
By standardizing on XML, different applications can more easily talk to one another, and this makes software a whole lot more interesting.
I keep reading about Web services, but I have never actually seen one. Can you show me a real Web service in action?
If you want a more intuitive feel for Web services, try out the IBM Web Services Browser, available on the IBM Alphaworks site. The browser provides a series of Web services demonstrations. Behind the scenes, it ties together SOAP, WSDL, and UDDI to provide a simple plug-and-play interface for finding and invoking Web services. For example, you can find a stock-quote service, a traffic-report service, and a weather service. Each service is independent, and you can stack services like building blocks. You can, therefore, create a single page that displays multiple services--where the end result looks like a stripped-down version of my.yahoo or my.excite.
What is the Web service protocol stack?
The Web service protocol stack is an evolving set of protocols used to define, discover, and implement Web services. The core protocol stack consists of four layers:
Service Transport: This layer is responsible for transporting messages between applications. Currently, this includes HTTP, SMTP, FTP, and newer protocols, such as Blocks Extensible Exchange Protocol (BEEP).
XML Messaging: This layer is responsible for encoding messages in a common XML format so that messages can be understood at either end. Currently, this includes XML-RPC and SOAP.
Service Description: This layer is responsible for describing the public interface to a specific Web service. Currently, service description is handled via the WSDL.
Service Discovery: This layer is responsible for centralizing services into a common registry, and providing easy publish/find functionality. Currently, service discovery is handled via the UDDI.
Beyond the essentials of XML-RPC, SOAP, WSDL, and UDDI, the Web service protocol stack includes a whole zoo of newer, evolving protocols. These include WSFL (Web Services Flow Language), SOAP-DSIG (SOAP Security Extensions: Digital Signature), and USML (UDDI Search Markup Language). For an overview of these protocols, check out Pavel Kulchenko's article, Web Services Acronyms, Demystified, on XML.com.
Fortunately, you do not need to understand the full protocol stack to get started with Web services. Assuming you already know the basics of HTTP, it is best to start at the XML Messaging layer and work your way up.
What is XML-RPC?
XML-RPC is a protocol that uses XML messages to perform Remote Procedure Calls. Requests are encoded in XML and sent via HTTP POST; XML responses are embedded in the body of the HTTP response.
More succinctly, XML-RPC = HTTP + XML + Remote Procedure Calls.
Because XML-RPC is platform independent, diverse applications can communicate with one another. For example, a Java client can speak XML-RPC to a Perl server.
To get a quick sense of XML-RPC, here is a sample XML-RPC request to a weather service (with the HTTP Headers omitted):
The request consists of a simple element, which specifies the method name (getWeather) and any method parameters (zip code).
Here is a sample XML-RPC response from the weather service:
The response consists of a single element, which specifies the return value (the current temperature). In this case, the return value is specified as an integer.
In many ways, XML-RPC is much simpler than SOAP, and therefore represents the easiest way to get started with Web services.
The official XML-RPC specification is available at XML-RPC.com. Dozens of XML-RPC implementations are available in Perl, Python, Java, and Ruby. See the XML-RPC home page for a complete list of implementations.
What is SOAP?
SOAP is an XML-based protocol for exchanging information between computers. Although SOAP can be used in a variety of messaging systems and can be delivered via a variety of transport protocols, the main focus of SOAP is Remote Procedure Calls (RPC) transported via HTTP. Like XML-RPC, SOAP is platform independent, and therefore enables diverse applications to communicate with one another.
To get a quick sense of SOAP, here is a sample SOAP request to a weather service (with the HTTP Headers omitted):
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xsd="http://www.w3.org/2001/XMLSchema">
SOAP-ENV:encodingStyle=" http://www.w3.org/2001/09/soap-encoding
As you can see, the request is slightly more complicated than XML-RPC and makes use of both XML namespaces and XML Schemas. Much like XML-RPC, however, the body of the request specifies both a method name (getWeather), and a list of parameters (zipcode).
Here is a sample SOAP response from the weather service:
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xsd="http://www.w3.org/2001/XMLSchema">
SOAP-ENV:encodingStyle="http://www.w3.org/2001/09/soap-encoding">
The response indicates a single integer return value (the current temperature).
The World Wide Web Consortium (W3C) is in the process of creating a SOAP standard. The latest working draft is designated as SOAP 1.2, and the specification is now broken into two parts. Part 1 describes the SOAP messaging framework and envelope specification. Part 2 describes the SOAP encoding rules, the SOAP-RPC convention, and HTTP binding details.
What is WSDL?
The Web Services Description Language (WSDL) currently represents the service description layer within the Web service protocol stack.
In a nutshell, WSDL is an XML grammar for specifying a public interface for a Web service. This public interface can include the following:
Information on all publicly available functions.
Data type information for all XML messages.
Binding information about the specific transport protocol to be used.
Address information for locating the specified service.
WSDL is not necessarily tied to a specific XML messaging system, but it does include built-in extensions for describing SOAP services.
Below is a sample WSDL file. This file describes the public interface for the weather service used in the SOAP example above. Obviously, there are many details to understanding the example. For now, just consider two points.
First, the
xmlns="http://schemas.xmlsoap.org/wsdl/"
xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/"
xmlns:tns="http://www.ecerami.com/wsdl/WeatherService.wsdl"
xmlns:xsd="http://www.w3.org/2001/XMLSchema">
namespace="urn:examples:weatherservice"
use="encoded"/>
Using WSDL, a client can locate a Web service, and invoke any of the publicly available functions. With WSDL-aware tools, this process can be entirely automated, enabling applications to easily integrate new services with little or no manual code. For example, check out the GLUE platform from the Mind Electric.
WSDL has been submitted to the W3C, but it currently has no official status within the W3C. See this W3C page for the latest draft.
What is UDDI?
UDDI (Universal Description, Discovery, and Integration) currently represents the discovery layer within the Web services protocol stack.
UDDI was originally created by Microsoft, IBM, and Ariba, and represents a technical specification for publishing and finding businesses and Web services.
At its core, UDDI consists of two parts.
First, UDDI is a technical specification for building a distributed directory of businesses and Web services. Data is stored within a specific XML format, and the UDDI specification includes API details for searching existing data and publishing new data.
Second, the UDDI Business Registry is a fully operational implementation of the UDDI specification. Launched in May 2001 by Microsoft and IBM, the UDDI registry now enables anyone to search existing UDDI data. It also enables any company to register themselves and their services.
The data captured within UDDI is divided into three main categories:
White Pages: This includes general information about a specific company. For example, business name, business description, and address.
Yellow Pages: This includes general classification data for either the company or the service offered. For example, this data may include industry, product, or geographic codes based on standard taxonomies.
Green Pages: This includes technical information about a Web service. Generally, this includes a pointer to an external specification, and an address for invoking the Web service.
You can view the Microsoft UDDI site, or the IBM UDDI site. The complete UDDI specification is available at uddi.org.
Beta versions of UDDI Version 2 are available at:
Hewlett Packard
IBM
Microsoft
SAP
How do I get started with Web Services?
The easiest way to get started with Web services is to learn XML-RPC. Check out the XML-RPC specification or read my book, Web Services Essentials. O'Reilly has also recently released a book on Programming Web Services with XML-RPC by Simon St.Laurent, Joe Johnston, and Edd Dumbill.
Once you have learned the basics of XML-RPC, move onto SOAP, WSDL, and UDDI. These topics are also covered in Web Services Essentials. For a comprehensive treatment of SOAP, check out O'Reilly's Programming Web Services with SOAP, by Doug Tidwell, James Snell, and Pavel Kulchenko.
Does the W3C support any Web service standards?
The World Wide Web Consortium (W3C) is actively pursuing standardization of Web service protocols. In September 2000, the W3C established an XML Protocol Activity. The goal of the group is to establish a formal standard for SOAP. A draft version of SOAP 1.2 is currently under review, and progressing through the official W3C recommendation process.
On January 25, 2002, the W3C also announced the formation of a Web Service Activity. This new activity will include the current SOAP work as well as two new groups. The first new group is the Web Services Description Working Group, which will take up work on WSDL. The second new group is the Web Services Architecture Working Group, which will attempt to create a cohesive framework for Web service protocols.
Performance/ LoadRunner Interview Questions
- What is load testing? - Load testing is to test that if the application works fine with the loads that result from large number of simultaneous users, transactions and to determine weather it can handle peak usage periods.
- What is Performance testing? - Timing for both read and update transactions should be gathered to determine whether system functions are being performed in an acceptable timeframe. This should be done standalone and then in a multi user environment to determine the effect of multiple transactions on the timing of a single transaction.
- Did u use LoadRunner? What version? - Yes. Version 7.2.
- Explain the Load testing process? -
Step 1: Planning the test. Here, we develop a clearly defined test plan to ensure the test scenarios we develop will accomplish load-testing objectives. Step 2: Creating Vusers. Here, we create Vuser scripts that contain tasks performed by each Vuser, tasks performed by Vusers as a whole, and tasks measured as transactions. Step 3: Creating the scenario. A scenario describes the events that occur during a testing session. It includes a list of machines, scripts, and Vusers that run during the scenario. We create scenarios using LoadRunner Controller. We can create manual scenarios as well as goal-oriented scenarios. In manual scenarios, we define the number of Vusers, the load generator machines, and percentage of Vusers to be assigned to each script. For web tests, we may create a goal-oriented scenario where we define the goal that our test has to achieve. LoadRunner automatically builds a scenario for us. Step 4: Running the scenario.
We emulate load on the server by instructing multiple Vusers to perform tasks simultaneously. Before the testing, we set the scenario configuration and scheduling. We can run the entire scenario, Vuser groups, or individual Vusers. Step 5: Monitoring the scenario.
We monitor scenario execution using the LoadRunner online runtime, transaction, system resource, Web resource, Web server resource, Web application server resource, database server resource, network delay, streaming media resource, firewall server resource, ERP server resource, and Java performance monitors. Step 6: Analyzing test results. During scenario execution, LoadRunner records the performance of the application under different loads. We use LoadRunner’s graphs and reports to analyze the application’s performance. - When do you do load and performance Testing? - We perform load testing once we are done with interface (GUI) testing. Modern system architectures are large and complex. Whereas single user testing primarily on functionality and user interface of a system component, application testing focuses on performance and reliability of an entire system. For example, a typical application-testing scenario might depict 1000 users logging in simultaneously to a system. This gives rise to issues such as what is the response time of the system, does it crash, will it go with different software applications and platforms, can it hold so many hundreds and thousands of users, etc. This is when we set do load and performance testing.
- What are the components of LoadRunner? - The components of LoadRunner are The Virtual User Generator, Controller, and the Agent process, LoadRunner Analysis and Monitoring, LoadRunner Books Online.
- What Component of LoadRunner would you use to record a Script? - The Virtual User Generator (VuGen) component is used to record a script. It enables you to develop Vuser scripts for a variety of application types and communication protocols.
- What Component of LoadRunner would you use to play Back the script in multi user mode? - The Controller component is used to playback the script in multi-user mode. This is done during a scenario run where a vuser script is executed by a number of vusers in a group.
- What is a rendezvous point? - You insert rendezvous points into Vuser scripts to emulate heavy user load on the server. 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. For example, to emulate peak load on the bank server, you can insert a rendezvous point instructing 100 Vusers to deposit cash into their accounts at the same time.
- What is a scenario? - A scenario defines the events that occur during each testing session. For example, a scenario defines and controls the number of users to emulate, the actions to be performed, and the machines on which the virtual users run their emulations.
- Explain the recording mode for web Vuser script? - We use VuGen to develop a Vuser script by recording a user performing typical business processes on a client application. VuGen creates the script by recording the activity between the client and the server. For example, in web based applications, VuGen monitors the client end of the database and traces all the requests sent to, and received from, the database server. We use VuGen to: Monitor the communication between the application and the server; Generate the required function calls; and Insert the generated function calls into a Vuser script.
- Why do you create parameters? - Parameters are like script variables. They are used to vary input to the server and to emulate real users. Different sets of data are sent to the server each time the script is run. Better simulate the usage model for more accurate testing from the Controller; one script can emulate many different users on the system.
- What is correlation? Explain the difference between automatic correlation and manual correlation? - Correlation is used to obtain data which are unique for each run of the script and which are generated by nested queries. Correlation provides the value to avoid errors arising out of duplicate values and also optimizing the code (to avoid nested queries). Automatic correlation is where we set some rules for correlation. It can be application server specific. Here values are replaced by data which are created by these rules. In manual correlation, the value we want to correlate is scanned and create correlation is used to correlate.
- How do you find out where correlation is required? Give few examples from your projects? - Two ways: First we can scan for correlations, and see the list of values which can be correlated. From this we can pick a value to be correlated. Secondly, we can record two scripts and compare them. We can look up the difference file to see for the values which needed to be correlated. In my project, there was a unique id developed for each customer, it was nothing but Insurance Number, it was generated automatically and it was sequential and this value was unique. I had to correlate this value, in order to avoid errors while running my script. I did using scan for correlation.
- Where do you set automatic correlation options? - Automatic correlation from web point of view can be set in recording options and correlation tab. Here we can enable correlation for the entire script and choose either issue online messages or offline actions, where we can define rules for that correlation. Automatic correlation for database can be done using show output window and scan for correlation and picking the correlate query tab and choose which query value we want to correlate. If we know the specific value to be correlated, we just do create correlation for the value and specify how the value to be created.
- What is a function to capture dynamic values in the web Vuser script? - Web_reg_save_param function saves dynamic data information to a parameter.
- When do you disable log in Virtual User Generator, When do you choose standard and extended logs? - Once we debug our script and verify that it is functional, we can enable logging for errors only. When we add a script to a scenario, logging is automatically disabled. Standard Log Option: When you select
Standard log, it creates a standard log of functions and messages sent during script execution to use for debugging. Disable this option for large load testing scenarios. When you copy a script to a scenario, logging is automatically disabled Extended Log Option: Select
extended log to create an extended log, including warnings and other messages. Disable this option for large load testing scenarios. When you copy a script to a scenario, logging is automatically disabled. We can specify which additional information should be added to the extended log using the Extended log options. - How do you debug a LoadRunner script? - VuGen contains two options to help debug Vuser scripts-the Run Step by Step command and breakpoints. The Debug settings in the Options dialog box allow us to determine the extent of the trace to be performed during scenario execution. The debug information is written to the Output window. We can manually set the message class within your script using the lr_set_debug_message function. This is useful if we want to receive debug information about a small section of the script only.
- How do you write user defined functions in LR? Give me few functions you wrote in your previous project? - Before we create the User Defined functions we need to create the external
library (DLL) with the function. We add this library to VuGen bin directory. Once the library is added then we assign user defined function as a parameter. The function should have the following format: __declspec (dllexport) char*(char*, char*)Examples of user defined functions are as follows:GetVersion, GetCurrentTime, GetPltform are some of the user defined functions used in my earlier project. - What are the changes you can make in run-time settings? - The Run Time Settings that we make are: a) Pacing - It has iteration count. b) Log - Under this we have Disable Logging Standard Log and c) Extended Think Time - In think time we have two options like Ignore think time and Replay think time. d) General - Under general tab we can set the vusers as process or as multithreading and whether each step as a transaction.
- Where do you set Iteration for Vuser testing? - We set Iterations in the Run Time Settings of the VuGen. The navigation for this is Run time settings, Pacing tab, set number of iterations.
- How do you perform functional testing under load? - Functionality under load can be tested by running several Vusers concurrently. By increasing the amount of Vusers, we can determine how much load the server can sustain.
- What is Ramp up? How do you set this? - This option is used to gradually increase the amount of Vusers/load on the server. An initial value is set and a value to wait between intervals can be
specified. To set Ramp Up, go to ‘Scenario Scheduling Options’ - What is the advantage of running the Vuser as thread? - VuGen provides the facility to use multithreading. This enables more Vusers to be run per
generator. If the Vuser is run as a process, the same driver program is loaded into memory for each Vuser, thus taking up a large amount of memory. This limits the number of Vusers that can be run on a single
generator. If the Vuser is run as a thread, only one instance of the driver program is loaded into memory for the given number of
Vusers (say 100). Each thread shares the memory of the parent driver program, thus enabling more Vusers to be run per generator. - If you want to stop the execution of your script on error, how do you do that? - The lr_abort function aborts the execution of a Vuser script. It instructs the Vuser to stop executing the Actions section, execute the vuser_end section and end the execution. This function is useful when you need to manually abort a script execution as a result of a specific error condition. When you end a script using this function, the Vuser is assigned the status "Stopped". For this to take effect, we have to first uncheck the “Continue on error†option in Run-Time Settings.
- What is the relation between Response Time and Throughput? - The Throughput graph shows the amount of data in bytes that the Vusers received from the server in a second. When we compare this with the transaction response time, we will notice that as throughput decreased, the response time also decreased. Similarly, the peak throughput and highest response time would occur approximately at the same time.
- Explain the Configuration of your systems? - The configuration of our systems refers to that of the client machines on which we run the Vusers. The configuration of any client machine includes its hardware settings, memory, operating system, software applications, development tools, etc. This system component configuration should match with the overall system configuration that would include the network infrastructure, the web server, the database server, and any other components that go with this larger system so as to achieve the load testing objectives.
- 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.
- If web server, database and Network are all fine where could be the problem? - The problem could be in the system itself or in the application server or in the code written for the application.
- How did you find web server related issues? - Using Web resource monitors we can find the performance of web servers. Using these monitors we can analyze throughput on the web server, number of hits per second that
occurred during scenario, the number of http responses per second, the number of downloaded pages per second. - How did you find database related issues? - By running “Database†monitor and help of “Data Resource Graph†we can find database related issues. E.g. You can specify the resource you want to measure on before running the controller and than you can see database related issues
- Explain all the web recording options?
- What is the difference between Overlay graph and Correlate graph? - Overlay Graph: It overlay the content of two graphs that shares a common x-axis. Left Y-axis on the merged graph show’s the current graph’s value & Right Y-axis show the value of Y-axis of the graph that was merged. Correlate Graph: Plot the Y-axis of two graphs against each other. The active graph’s Y-axis becomes X-axis of merged graph. Y-axis of the graph that was merged becomes merged graph’s Y-axis.
- How did you plan the Load? What are the Criteria? - Load test is planned to decide the number of users, what kind of machines we are going to use and from where they are run. It is based on 2 important documents, Task Distribution Diagram and Transaction profile. Task Distribution Diagram gives us the information on number of users for a particular transaction and the time of the load. The peak usage and off-usage are decided from this Diagram. Transaction profile gives us the information about the transactions name and their priority levels with regard to the scenario we are deciding.
- What does vuser_init action contain? - Vuser_init action contains procedures to login to a server.
- What does vuser_end action contain? - Vuser_end section contains log off procedures.
- What is think time? How do you change the threshold? - Think time is the time that a real user waits between actions. Example: When a user receives data from a server, the user may wait several seconds to review the data before responding. This delay is known as the think time. Changing the Threshold: Threshold level is the level below which the recorded think time will be ignored. The default value is five (5) seconds. We can change the think time threshold in the Recording options of the Vugen.
- What is the difference between standard log and extended log? - The standard log sends a subset of functions and messages sent during script execution to a log. The subset depends on the Vuser type Extended log sends a detailed script execution messages to the output log. This is mainly used during debugging when we want information about: Parameter substitution. Data returned by the server. Advanced trace.
- Explain the following functions: - lr_debug_message - The lr_debug_message function sends a debug message to the output log when the specified message class is set. lr_output_message - The lr_output_message function sends notifications to the Controller Output window and the Vuser log file. lr_error_message - The lr_error_message function sends an error message to the LoadRunner Output window. lrd_stmt - The lrd_stmt function associates a character string (usually a SQL statement) with a cursor. This function sets a SQL statement to be processed. lrd_fetch - The lrd_fetch function fetches the next row from the result set.
- Throughput - If the throughput scales upward as time progresses and the number of Vusers increase, this indicates that the bandwidth is sufficient. If the graph were to remain relatively flat as the number of Vusers increased, it would
be reasonable to conclude that the bandwidth is constraining the volume of
data delivered. - Types of Goals in Goal-Oriented Scenario - Load Runner provides you with five different types of goals in a goal oriented scenario:
- The number of concurrent Vusers
- The number of hits per second
- The number of transactions per second
- The number of pages per minute
- The transaction response time that you want your scenario
- Analysis Scenario (Bottlenecks): In Running Vuser graph correlated with the response time graph you can see that as the number of Vusers increases, the average response time of the check itinerary transaction very gradually increases. In other words, the average response time steadily increases as the load
increases. At 56 Vusers, there is a sudden, sharp increase in the average response
time. We say that the test broke the server. That is the mean time before failure (MTBF). The response time clearly began to degrade when there were more than 56 Vusers running simultaneously. - What is correlation? Explain the difference between automatic correlation and manual correlation? - Correlation is used to obtain data which are unique for each run of the script and which are generated by nested queries. Correlation provides the value to avoid errors arising out of duplicate values and also optimizing the code (to avoid nested queries). Automatic correlation is where we set some rules for correlation. It can be application server specific. Here values are replaced by data which are created by these rules. In manual correlation, the value we want to correlate is scanned and create correlation is used to correlate.
- Where do you set automatic correlation options? - Automatic correlation from web point of view, can be set in recording options and correlation tab. Here we can enable correlation for the entire script and choose either issue online messages or offline actions, where we can define rules for that correlation. Automatic correlation for database, can be done using show output window and scan for correlation and picking the correlate query tab and choose which query value we want to correlate. If we know the specific value to be correlated, we just do create correlation for the value and specify how the value to be created.
- What is a function to capture dynamic values in the web vuser script? - Web_reg_save_param function saves dynamic data information to a parameter.
Monday, February 21, 2011
What is User Acceptance Testing? What is UAT Testing?
What is User Acceptance Testing?
User Acceptance Testing is often the final step before rolling out the application.
Usually the end users who will be using the applications test the application before ‘accepting’ the application.
This type of testing gives the end users the confidence that the application being delivered to them meets their requirements.
This testing also helps nail bugs related to usability of the application.
User Acceptance Testing – Prerequisites:
Before the User Acceptance testing can be done the application is fully developed.
Various levels of testing (Unit, Integration and System) are already completed before User Acceptance Testing is done. As various levels of testing have been completed most of the technical bugs have already been fixed before UAT.
User Acceptance Testing – What to Test?
To ensure an effective User Acceptance Testing Test cases are created.
These Test cases can be created using various use cases identified during the Requirements definition stage.
The Test cases ensure proper coverage of all the scenarios during testing.
During this type of testing the specific focus is the exact real world usage of the application. The Testing is done in an environment that simulates the production environment.
The Test cases are written using real world scenarios for the application
User Acceptance Testing – How to Test?
The user acceptance testing is usually a black box type of testing. In other words, the focus is on the functionality and the usability of the application rather than the technical aspects. It is generally assumed that the application would have already undergone Unit, Integration and System Level Testing.
However, it is useful if the User acceptance Testing is carried out in an environment that closely resembles the real world or production environment.
The steps taken for User Acceptance Testing typically involve one or more of the following:
.......1) User Acceptance Test (UAT) Planning
.......2) Designing UA Test Cases
.......3) Selecting a Team that would execute the (UAT) Test Cases
.......4) Executing Test Cases
.......5) Documenting the Defects found during UAT
.......6) Resolving the issues/Bug Fixing
.......7) Sign Off
User Acceptance Test (UAT) Planning:
As always the Planning Process is the most important of all the steps. This affects the effectiveness of the Testing Process. The Planning process outlines the User Acceptance Testing Strategy. It also describes the key focus areas, entry and exit criteria.
Designing UA Test Cases:
The User Acceptance Test Cases help the Test Execution Team to test the application thoroughly. This also helps ensure that the UA Testing provides sufficient coverage of all the scenarios.
The Use Cases created during the Requirements definition phase may be used as inputs for creating Test Cases. The inputs from Business Analysts and Subject Matter Experts are also used for creating.
Each User Acceptance Test Case describes in a simple language the precise steps to be taken to test something.
The Business Analysts and the Project Team review the User Acceptance Test Cases.
Selecting a Team that would execute the (UAT) Test Cases:
Selecting a Team that would execute the UAT Test Cases is an important step.
The UAT Team is generally a good representation of the real world end users.
The Team thus comprises of the actual end users who will be using the application.
Executing Test Cases:
The Testing Team executes the Test Cases and may additional perform random Tests relevant to them
Documenting the Defects found during UAT:
The Team logs their comments and any defects or issues found during testing.
Resolving the issues/Bug Fixing:
The issues/defects found during Testing are discussed with the Project Team, Subject Matter Experts and Business Analysts. The issues are resolved as per the mutual consensus and to the satisfaction of the end users.
Sign Off:
Upon successful completion of the User Acceptance Testing and resolution of the issues the team generally indicates the acceptance of the application. This step is important in commercial software sales. Once the User “Accept” the Software delivered they indicate that the software meets their requirements.
The users now confident of the software solution delivered and the vendor can be paid for the same.
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