LoadRunner interview questions

1.       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.

2.       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.

3.       Did u use LoadRunner? What version? - Yes. Version 7.2.

4.       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 scrīpts 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, scrīpts, 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 scrīpt. 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.

5.       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.

6.       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.

7.       What Component of LoadRunner would you use to record a scrīpt? - The Virtual User Generator (VuGen) component is used to record a scrīpt. It enables you to develop Vuser scrīpts for a variety of application types and communication protocols.

8.       What Component of LoadRunner would you use to play Back the scrīpt in multi user mode? - The Controller component is used to playback the scrīpt in multi-user mode. This is done during a scenario run where a vuser scrīpt is executed by a number of vusers in a group.

9.       What is a rendezvous point? - You insert rendezvous points into Vuser scrīpts 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.

10.   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.

11.   Explain the recording mode for web Vuser scrīpt? - We use VuGen to develop a Vuser scrīpt by recording a user performing typical business processes on a client application. VuGen creates the scrīpt 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 scrīpt.

12.   Why do you create parameters? - Parameters are like scrīpt 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 scrīpt is run. Better simulate the usage model for more accurate testing from the Controller; one scrīpt can emulate many different users on the system.

13.   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 scrīpt 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.

14.   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 scrīpts 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 scrīpt. I did using scan for correlation.

15.   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 scrīpt 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.

16.   What is a function to capture dynamic values in the web Vuser scrīpt? - Web_reg_save_param function saves dynamic data information to a parameter.

17.   When do you disable log in Virtual User Generator, When do you choose standard and extended logs? - Once we debug our scrīpt and verify that it is functional, we can enable logging for errors only. When we add a scrīpt 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 scrīpt execution to use for debugging. Disable this option for large load testing scenarios. When you copy a scrīpt 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 scrīpt 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.

18.   How do you debug a LoadRunner scrīpt? - VuGen contains two options to help debug Vuser scrīpts-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 scrīpt using the lr_set_debug_message function. This is useful if we want to receive debug information about a small section of the scrīpt only.

19.   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* <function name>(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.

20.   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.

21.   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.

22.   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.

23.   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’

24.   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.

25.   If you want to stop the execution of your scrīpt on error, how do you do that? - The lr_abort function aborts the execution of a Vuser scrīpt. 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 scrīpt execution as a result of a specific error condition. When you end a scrīpt 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.  

26.   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.

27.   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.

28.   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.

29.   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.

30.   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.

31.   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

32.   Explain all the web recording options?

33.   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.

34.   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.

35.   What does vuser_init action contain? - Vuser_init action contains procedures to login to a server.

36.   What does vuser_end action contain? - Vuser_end section contains log off procedures.  

37.   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.

38.   What is the difference between standard log and extended log? - The standard log sends a subset of functions and messages sent during scrīpt execution to a log. The subset depends on the Vuser type Extended log sends a detailed scrīpt 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.

39.   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.

40.   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. 

41.   Types of Goals in Goal-Oriented Scenario -  Load Runner provides you with five different types of goals in a goal oriented scenario:

o    The number of concurrent Vusers

o    The number of hits per second

o    The number of transactions per second

o    The number of pages per minute

o    The transaction response time that you want your scenario

42.   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.

43.   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 scrīpt 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.

44.   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 scrīpt 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.

45.   What is a function to capture dynamic values in the web vuser scrīpt? - Web_reg_save_param function saves dynamic data information to a parameter.

 

Loadrunner中参数设置详细分析

相信对大家会有用的，这个版本是基于7.8的。
做负载或者压力测试时，很多人选择使用了Loadrunner测试工具。该工具的基本流程是先将用户的实际操作录制成脚本，然后产生数千个虚拟用户运行脚本（虚拟用户可以分布在局域网中不同的PC机上），最后生成相关的报告以及分析图。但是在录制脚本的过程中会遇到很多实际的问题，比如不同的用户有不同的使用数据，这就牵涉到参数的设置问题。本文就Loadrunner中参数的设置进行说明，希望对大家有所帮助。
    在录制程序运行的过程中，VuGen（脚本生成器） 自动生成了包含录制过程中实际用到的数值的脚本。如果你企图在录制的脚本中使用不同的数值执行脚本的活动（如查询、提交等等），那么你必须用参数值取代录制的数值。这个过程称为参数化脚本。
    本文主要包括如下内容：理解参数的局限性、建立参数、定义参数的属性、理解参数的类型、为局部数据类型设置参数的属性、为数据文件设置参数的属性、从已经存在的数据库中引入数据。
    除了GUI，以下的内容适合于各种类型的用户脚本。
一、关于参数的定义
    在你录制程序运行的过程中，脚本生成器自动生成由函数组成的用户脚本。函数中参数的值就是在录制过程中输入的实际值。
    例如，你录制了一个Web应用程序的脚本。脚本生成器生成了一个声明，该声明搜索名称为“UNIX”的图书的数据库。当你用多个虚拟用户和迭代回放脚本时，也许你不想重复使用相同的值“UNIX”。那么，你就可以用参数来取代这个常量。结果就是你可以用指定的数据源的数值来取代参数值。数据源可以是一个文件，也可以是内部产生的变量。
    用参数表示用户的脚本有两个优点：
① 可以使脚本的长度变短。
② 可以使用不同的数值来测试你的脚本。例如，如果你企图搜索不同名称的图书，你仅仅需要写提交函数一次。在回放的过程中，你可以使用不同的参数值，而不只搜索一个特定名称的值。
    参数化包含以下两项任务：
① 在脚本中用参数取代常量值。
② 设置参数的属性以及数据源。
    参数化仅可以用于一个函数中的参量。你不能用参数表示非函数参数的字符串。另外，不是所有的函数都可以参数化的。

 

二、参数的创建
    可以指定名称和类型来创建参数。不存在对脚本中参数个数的限制。在Web程序的用户脚本中，你可以使用如下过程在基于文本的脚本视图中创建参数。或者，也可以在基于图标的树形视图中创建参数。
    在基于文本的脚本视图中创建一个参数：
1、 将光标定位在要参数化的字符上，点击右键。打开弹出菜单。
2、 在弹出菜单中，选择“Replace with a Parameter”。选择或者创建参数的对话框弹出。
3、 在“Parameter name”中输入参数的名称，或者选择一个在参数列表中已经存在的参数。
4、 在“Parameter type”下拉列表中选择参数类型。
5、 点击“OK”，关闭该对话框。脚本生成器便会用参数中的值来取代脚本中被参数化的字符，参数用一对“{}”括住。
    注意：在参数化CORBA或者General-Java 用户脚本的时候，必须参数化整个字符串，而不是其中的部分。另外注意：除了Web或者WAP，缺省的参数括号对于任何脚本都是 “{}”。你可以在“General Options”对话框中的“Parameterization”标签（Tools>General Options）中定义参数括号种类。
6、 用同样的参数替换字符的其余情况，选中参数，点击右键，弹出菜单。从弹出的菜单中，选择“Replace More Occurrences”。搜索和替换对话框弹出。“Find What”中显示了你企图替换的值。“Replace With”中显示了括号中参数的名称。选择适当的检验框来匹配整个字符或者大小写。如果要搜索规则的表达式（.，!，?等等），选中“Regular Expression”检验框，然后点击“Replace”或者“Replace All”。
    注意：小心使用“Replace All”，尤其替换数字字符串的时候。脚本生成器将会替换字符出现的所有情况。
7、 如果想用以前定义过的参数来替换常量字符串的话，选中该字符串，点击右键，然后选择“Use Existing Parameter”，子菜单“Use Existing Parameters”弹出。从子菜单“Use Existing Parameters”选择参数，或者用“Select from Parameter List”来打开参数列表对话框。
    注意：如果用以前定义过的参数来替换常量字符串的话，那么，使用“Parameter List”非常方便。同时，还可以查看和修改该参数的属性。
8、 对于已经用参数替换过的地方，如果想取回原来的值，那么，就在参数上点击右键，然后选择“Restore Original value”。
    在Web用户脚本的树形视图中创建参数：
1、将光标定位在企图参数化的地方，点击右键，从弹出的菜单中选择“Properties”。则相关的属性对话框打开。
2、点击在要参数化的参量的旁边的“ABC”形状的图标。“Select or Create Parameter”对话框打开。
3、在“Parameter name”中输入参数的名称，或者从列表中选择一个已经存在的参数。
4、在“Parameter type”中输入参数的类型。
5、点击“OK”关闭该对话框。用户脚本生成器会用参数来替换最初的字符串常量，并用一个表格形状的图标替换“ABC”形状的图标。
6、要恢复参数化以前的值，点击图标，然后从弹出的菜单中选择“Undo Parameter”，则以前的值便会重现。

 

三、定义参数的属性
    创建参数完成后，就可以定义其属性了。参数的属性定义就是定义在脚本执行过程中，参数使用的数据源。在Web用户脚本中，你既可以在基于文本的脚本视图中定义参数属性，也可以在基于图标的树形视图中定义参数属性。下面的过程将教你如何在基于本文的脚本视图中定义参数属性。
    在基于文本的脚本视图中定义参数属性步骤：
1、 在参数上点击右键，有菜单弹出。
2、 在弹出的菜单中，选择“Parameter Properties”。参数属性对话框打开，显示和当前参数类型相关的属性。
3、 输入参数的属性值。
4、 点击“Close”关闭参数属性对话框。
    在Web用户脚本的树形视图中定义参数的属性：
1、 将关标定位在参数上，然后点击右键，选择“Properties”。属性对话框打开。
2、 点击要定义属性的参数旁边的表格形状按钮，点击右键，选择“Parameter Properties”。参数属性对话框打开，和参数类型相关的属性显示出来。
3、 输入参数的属性。
4、 点击“Close”关闭参数属性对话框。
    使用参数列表：
　　使用参数列表可以在任意时刻查看所有的参数，创建新的参数、删除参数，或者修改已经存在参数的属性。
1、 点击参数列表按钮或者用“Vuser>Parameter List”。参数列表对话框打开。
2、 要创建新的参数，点击“New”按钮。新的参数则被添加在参数树中，该参数有一个临时的名字，你可以给它重新命名，然后回车。设置参数的类型和属性，点击“OK”，关闭参数列表对话框。
    注意：不要将一个参数命名为“unique”，因为这个名称是用户脚本生成器本身的。用户脚本生成器创建新的参数，但是不会自动用该参数在脚本中替换任意选中的字符串。
3、 要删除已有的参数，那么，要先从参数树中选择该参数，点击“Delete”，然后确认你的行为即可。
4、 要修改已有参数，那么，要先从参数树中选择该参数，然后编辑参数的类型和属性。

四、理解参数的类型
　　在你定义参数属性的时候，要指定参数值的数据源。你可以指定下列数据源类型的任何一种：
Internal Data―― 虚拟用户内部产生的数据。
Data Files ――存在于文件中的数据。可能是已存在的文件或者是用脚本生成器新创建的。
User-Defined Functions―― 调用外部DLL函数生成的数据
　　Internal Data包括以下几种：
1、 Date/Time
　　Date/Time用当前的日期/时间替换参数。要指定一个Date/Time格式，你可以从菜单列表中选择格式，或者指定你自己的格式。这个格式应该和你脚本中录制的Date/Time格式保持一致。
2、 Group Name
　　Group Name 用虚拟用户组名称替换参数。在创建scenario的时候，你可以指定虚拟用户组的名称。当从用户脚本生成器运行脚本的时候，虚拟用户组名称总是None。
3、 Load Generator Name
　　Load Generator Name用脚本负载生成器的名称替换参数。负载生成器是虚拟用户在运行的计算机。
4. Iteration Number
　　Iteration Number用当前的迭代数目替换参数。
5、 Random Number
　　Random Number用一个随机数替换参数。通过指定最大值和最小值来设置随机数的范围。
6、 Unique Number
　　Unique Number用一个唯一的数字来替换参数。你可以指定一个起始数字和一个块的大小。
7、 Vuser ID
　　Vuser ID用分配给虚拟用户的ID替换参数，ID是由Loadrunner的控制器在scenario运行时生成的。如果你从脚本生成器运行脚本的话，虚拟用户的ID总是-1。

五、数据文件
　　数据文件包含着脚本执行过程中虚拟用户访问的数据。局部和全局文件中都可以存储数据。可以指定现有的ASCII文件、用脚本生成器创建一个新的文件或者引入一个数据库。在参数有很多已知值的时候数据文件非常有用。数据文件中的数据是以表的形式存储的。一个文件中可以包含很多参数值。每一列包含一个参数的数据。列之间用分隔符隔开，比如说，用逗号。
　　对数据文件设置参数属性
　　如果使用文件作为参数的数据源，必须指定以下内容：文件的名称和位置、包含数据的列、文件格式，包括列的分隔符、更新方法。
　　如果参数的类型是“File”，打开参数属性（Parameter Properties）对话框，设置文件属性如下：
1、 在“File path”中输入文件的位置，或者点击“Browse”指定一个已有文件的位置。缺省情况下，所有新的数据文件名都是“parameter_name.dat”，注意，已有的数据文件的后缀必须是.dat。
2、 点击“Edit”。记事本打开，里面第一行是参数的名称，第二行是参数的初始值。使用诸如逗号之类的分隔符将列隔开。对于每一新的表行开始一行新的数据。
　　注意：在没有启动记事本的情况下如果想添加列，就在参数属性对话框中点击“Add Col”，那么“Add new column”对话框就会弹出。输入新列的名称，点击“OK”。脚本生成器就会添加该列到表中，并显示该列的初始值。
3、 在“Select Column”部分，指明包含当前参数数据的列。你可以指定列名或者列号。列号是包含你所需要数据的列的索引。列名显示在每列的第一行（row 0）。
4、 在“Column delimiter”中输入列分隔符，你可以指定逗号、空格符等等。
5、 在“First data line”中，在脚本执行的时候选择第一行数据使用。列标题是第0行。若从列标题后面的第一行开始的话，那就在“First data line”中输入1。如果没有列标题，就输入0。
6、 在“Select next row”中输入更新方法，以说明虚拟用户在脚本执行的过程中如何选择表中的数据。方法可以是：连续的、随机的、唯一的、或者与其它参数表的相同行。
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