package com.ibm.jmetertest;  import java.sql.*;    public class JMeterPopulator  {    public static void main(String[] args)    {      try      {        Class.forName("COM.ibm.db2.jdbc.app.DB2Driver");  	String dbName = "loaddb";  	String url = "jdbc:db2:" + dbName;  	String userName = "db2admin";  	String password = "db2admin";  	Connection con            = DriverManager.getConnection(url,userName, password);  	int numOfTestRecords = 30000;  	PreparedStatement statement            = con.prepareStatement("INSERT INTO LOADTABLE VALUES(?,?,?)");  	for (int i =0; i<numOfTestRecords; i++)  	{  	  statement.setString(1,"Col1Test-" + i);  	  statement.setString(2,"Col2Test-" + i);  	  statement.setString(3,"Col3Test-" + i);  	  statement.executeUpdate();  	  System.out.println(i);  	}      }      catch(Exception e)      {         System.out.println("An error has occurred: " + e.toString());         e.printStackTrace();      }    }  }    

• Columns to display: Choose the column(s) to display in graph.
• Rectangles color: Clic on right color rectangle open a popup dialog to choose a custom color for column.
• Foreground color Allow to change the value text color.
• Value font: Allow to define font settings for the text.
• Draw outlines bar? To draw or not the border line on bar chart
• Show number grouping? Show or not the number grouping in Y Axis labels.
• Value labels vertical? Change orientation for value label. (Default is horizontal)
• Column label selection: Filter by result label. A regular expression can be used, example: .*Transaction.* 
  Before display the graph, click on Apply filter button to refresh internal data.

18.3.15 BeanShell Listener

The BeanShell Listener allows the use of BeanShell for processing samples for saving etc.

For full details on using BeanShell, please see the BeanShell website.

The test element supports the ThreadListener and TestListener methods. These should be defined in the initialisation file. See the file BeanShellListeners.bshrc for example definitions.

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Parameters

Before invoking the script, some variables are set up in the BeanShell interpreter:

• log - (Logger) - can be used to write to the log file
• ctx - ( JMeterContext ) - gives access to the context
• vars - ( JMeterVariables ) - gives read/write access to variables: vars.get(key); vars.put(key,val); vars.putObject("OBJ1",new Object());
• props - (JMeterProperties - class java.util.Properties) - e.g. props.get("START.HMS"); props.put("PROP1","1234");
• sampleResult, prev - ( SampleResult ) - gives access to the previous SampleResult
• sampleEvent ( SampleEvent ) gives access to the current sample event

For details of all the methods available on each of the above variables, please check the Javadoc

If the property beanshell.listener.init is defined, this is used to load an initialisation file, which can be used to define methods etc for use in the BeanShell script.

18.3.18 BSF Listener

The BSF Listener allows BSF script code to be applied to sample results.

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Parameters

The script (or file) is processed using the BSFEngine.exec() method, which does not return a value.

Before invoking the script, some variables are set up. Note that these are BSF variables - i.e. they can be used directly in the script.

• log - (Logger) - can be used to write to the log file
• Label - the String Label
• Filename - the script file name (if any)
• Parameters - the parameters (as a String)
• args[] - the parameters as a String array (split on whitespace)
• ctx - ( JMeterContext ) - gives access to the context
• vars - ( JMeterVariables ) - gives read/write access to variables: vars.get(key); vars.put(key,val); vars.putObject("OBJ1",new Object()); vars.getObject("OBJ2");
• props - (JMeterProperties - class java.util.Properties) - e.g. props.get("START.HMS"); props.put("PROP1","1234");
• sampleResult, prev - ( SampleResult ) - gives access to the SampleResult
• sampleEvent - ( SampleEvent ) - gives access to the SampleEvent
• sampler - (Sampler)- gives access to the last sampler
• OUT - System.out - e.g. OUT.println("message")

For details of all the methods available on each of the above variables, please check the Javadoc

18.3.20 Comparison Assertion Visualizer

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Parameters

18.3.11 Distribution Graph (alpha)

The distribution graph will display a bar for every unique response time. Since the granularity of System.currentTimeMillis() is 10 milliseconds, the 90% threshold should be within the width of the graph. The graph will draw two threshold lines: 50% and 90%. What this means is 50% of the response times finished between 0 and the line. The same is true of 90% line. Several tests with Tomcat were performed using 30 threads for 600K requests. The graph was able to display the distribution without any problems and both the 50% and 90% line were within the width of the graph. A performant application will generally produce results that clump together. A poorly written application that has memory leaks may result in wild fluctuations. In those situations, the threshold lines may be beyond the width of the graph. The recommended solution to this specific problem is fix the webapp so it performs well. If your test plan produces distribution graphs with no apparent clumping or pattern, it may indicate a memory leak. The only way to know for sure is to use a profiling tool.

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18.3.13 Response Time Graph

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The figure below shows an example of settings to draw this graph.

 

Response time graph settings

 

 

Please note: All this parameters aren't saved in JMeter jmx script.

Parameters

18.3.9 Simple Data Writer

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18.3.4 Spline Visualizer

The Spline Visualizer provides a view of all sample times from the start of the test till the end, regardless of how many samples have been taken. The spline has 10 points, each representing 10% of the samples, and connected using spline logic to show a single continuous line.

The graph is automatically scaled to fit within the window. This needs to be borne in mind when comparing graphs.

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8.3.16 Summary Report

The thoughput is calculated from the point of view of the sampler target (e.g. the remote server in the case of HTTP samples). JMeter takes into account the total time over which the requests have been generated. If other samplers and timers are in the same thread, these will increase the total time, and therefore reduce the throughput value. So two identical samplers with different names will have half the throughput of two samplers with the same name. It is important to choose the sampler labels correctly to get the best results from the Report.

• Label - The label of the sample. If "Include group name in label?" is selected, then the name of the thread group is added as a prefix. This allows identical labels from different thread groups to be collated separately if required.
• # Samples - The number of samples with the same label
• Average - The average elapsed time of a set of results
• Min - The lowest elapsed time for the samples with the same label
• Max - The longest elapsed time for the samples with the same label
• Std. Dev. - the Standard Deviation of the sample elapsed time
• Error % - Percent of requests with errors
• Throughput - the Throughput is measured in requests per second/minute/hour. The time unit is chosen so that the displayed rate is at least 1.0. When the throughput is saved to a CSV file, it is expressed in requests/second, i.e. 30.0 requests/minute is saved as 0.5.
• Kb/sec - The throughput measured in Kilobytes per second
• Avg. Bytes - average size of the sample response in bytes. (in JMeter 2.2 it wrongly showed the value in kB)

Times are in milliseconds.

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The figure below shows an example of selecting the "Include group name" checkbox.

 

Sample "Include group name" display

 

 

18.3.17 Save Responses to a file

This test element can be placed anywhere in the test plan. For each sample in its scope, it will create a file of the response Data. The primary use for this is in creating functional tests, but it can also be useful where the response is too large to be displayed in the View Results Tree Listener. The file name is created from the specified prefix, plus a number (unless this is disabled, see below). The file extension is created from the document type, if known. If not known, the file extension is set to 'unknown'. If numbering is disabled, and adding a suffix is disabled, then the file prefix is taken as the entire file name. This allows a fixed file name to be generated if required. The generated file name is stored in the sample response, and can be saved in the test log output file if required.

The current sample is saved first, followed by any sub-samples (child samples). If a variable name is provided, then the names of the files are saved in the order that the sub-samples appear. See below.

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Parameters

18.3.3 Graph Results

The Graph Results listener generates a simple graph that plots all sample times. Along the bottom of the graph, the current sample (black), the current average of all samples(blue), the current standard deviation (red), and the current throughput rate (green) are displayed in milliseconds.

The throughput number represents the actual number of requests/minute the server handled. This calculation includes any delays you added to your test and JMeter's own internal processing time. The advantage of doing the calculation like this is that this number represents something real - your server in fact handled that many requests per minute, and you can increase the number of threads and/or decrease the delays to discover your server's maximum throughput. Whereas if you made calculations that factored out delays and JMeter's processing, it would be unclear what you could conclude from that number.

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The following table briefly describes the items on the graph. Further details on the precise meaning of the statistical terms can be found on the web - e.g. Wikipedia - or by consulting a book on statistics.

• Data - plot the actual data values
• Average - plot the Average
• Median - plot the Median (midway value)
• Deviation - plot the Standard Deviation (a measure of the variation)
• Throughput - plot the number of samples per unit of time

The individual figures at the bottom of the display are the current values. "Latest Sample" is the current elapsed sample time, shown on the graph as "Data".

18.3.5 Assertion Results

The Assertion Results visualizer shows the Label of each sample taken. It also reports failures of any Assertions that are part of the test plan.

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See Also:

• Response Assertion

18.3.19 Generate Summary Results

# Define the following property to automatically start a summariser with that name # (applies to non-GUI mode only) #summariser.name=summary # # interval between summaries (in seconds) default 3 minutes #summariser.interval=180 # # Write messages to log file #summariser.log=true # # Write messages to System.out #summariser.out=true  

label +   171 in  20.3s =    8.4/s Avg:  1129 Min:  1000 Max:  1250 Err:     0 (0.00%) label +   263 in  31.3s =    8.4/s Avg:  1138 Min:  1000 Max:  1250 Err:     0 (0.00%) label =   434 in  50.4s =    8.6/s Avg:  1135 Min:  1000 Max:  1250 Err:     0 (0.00%) label +   263 in  31.0s =    8.5/s Avg:  1138 Min:  1000 Max:  1250 Err:     0 (0.00%) label =   697 in  80.3s =    8.7/s Avg:  1136 Min:  1000 Max:  1250 Err:     0 (0.00%) label +   109 in  12.4s =    8.8/s Avg:  1092 Min:    47 Max:  1250 Err:     0 (0.00%) label =   806 in  91.6s =    8.8/s Avg:  1130 Min:    47 Max:  1250 Err:     0 (0.00%)  

The label is used to group sample results together. So if you have multiple Thread Groups and want to summarize across them all, then use the same label - or add the summariser to the Test Plan (so all thread groups are in scope). Different summary groupings can be implemented by using suitable labels and adding the summarisers to appropriate parts of the test plan.

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Parameters

18.3.8 View Results in Table

By default, it only displays the main (parent) samples; it does not display the sub-samples (child samples). Versions of JMeter after 2.5.1 have a "Child Samples?" check-box. If this is selected, then the sub-samples are displayed instead of the main samples.

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18.3.10 Monitor Results

Monitor Results is a new Visualizer for displaying server status. It is designed for Tomcat 5, but any servlet container can port the status servlet and use this monitor. There are two primary tabs for the monitor. The first is the "Health" tab, which will show the status of one or more servers. The second tab labled "Performance" shows the performance for one server for the last 1000 samples. The equations used for the load calculation is included in the Visualizer.

Currently, the primary limitation of the monitor is system memory. A quick benchmark of memory usage indicates a buffer of 1000 data points for 100 servers would take roughly 10Mb of RAM. On a 1.4Ghz centrino laptop with 1Gb of ram, the monitor should be able to handle several hundred servers.

As a general rule, monitoring production systems should take care to set an appropriate interval. Intervals shorter than 5 seconds are too aggressive and have a potential of impacting the server. With a buffer of 1000 data points at 5 second intervals, the monitor would check the server status 12 times a minute or 720 times a hour. This means the buffer shows the performance history of each machine for the last hour.

For a detailed description of how to use the monitor, please refer to Building a Monitor Test Plan

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8.3.7 Aggregate Report

The thoughput is calculated from the point of view of the sampler target (e.g. the remote server in the case of HTTP samples). JMeter takes into account the total time over which the requests have been generated. If other samplers and timers are in the same thread, these will increase the total time, and therefore reduce the throughput value. So two identical samplers with different names will have half the throughput of two samplers with the same name. It is important to choose the sampler names correctly to get the best results from the Aggregate Report.

Calculation of the Median and 90% Line (90 ^th percentile ) values requires additional memory. For JMeter 2.3.4 and earlier, details of each sample were saved separately, which meant a lot of memory was needed. JMeter now combines samples with the same elapsed time, so far less memory is used. However, for samples that take more than a few seconds, the probability is that fewer samples will have identical times, in which case more memory will be needed. See the Summary Report for a similar Listener that does not store individual samples and so needs constant memory.

• Label - The label of the sample. If "Include group name in label?" is selected, then the name of the thread group is added as a prefix. This allows identical labels from different thread groups to be collated separately if required.
• # Samples - The number of samples with the same label
• Average - The average time of a set of results
• Median - The median is the time in the middle of a set of results. 50% of the samples took no more than this time; the remainder took at least as long.
• 90% Line - 90% of the samples took no more than this time. The remaining samples at least as long as this. (90 ^th percentile )
• Min - The shortest time for the samples with the same label
• Max - The longest time for the samples with the same label
• Error % - Percent of requests with errors
• Throughput - the Throughput is measured in requests per second/minute/hour. The time unit is chosen so that the displayed rate is at least 1.0. When the throughput is saved to a CSV file, it is expressed in requests/second, i.e. 30.0 requests/minute is saved as 0.5.
• Kb/sec - The throughput measured in Kilobytes per second

Times are in milliseconds.

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The figure below shows an example of selecting the "Include group name" checkbox.

 

Sample "Include group name" display

 

 

18.3.14 Mailer Visualizer

The mailer visualizer can be set up to send email if a test run receives too many failed responses from the server.

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Parameters

• Parameters - string containing the parameters as a single variable
• bsh.args - String array containing parameters, split on white-space

18.5.10 BSF Assertion

The BSF Assertion allows BSF script code to be used to check the status of the previous sample.

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Parameters

The script (or file) is processed using the BSFEngine.exec() method, which does not return a value.

The following variables are set up for use by the script:

• log - (Logger) - can be used to write to the log file
• Label - the String Label
• Filename - the script file name (if any)
• Parameters - the parameters (as a String)
• args[] - the parameters as a String array (split on whitespace)
• ctx - ( JMeterContext ) - gives access to the context
• vars - ( JMeterVariables ) - gives read/write access to variables: vars.get(key); vars.put(key,val); vars.putObject("OBJ1",new Object()); vars.getObject("OBJ2");
• props - (JMeterProperties - class java.util.Properties) - e.g. props.get("START.HMS"); props.put("PROP1","1234");
• SampleResult, prev - ( SampleResult ) - gives access to the previous SampleResult (if any)
• sampler - (Sampler)- gives access to the current sampler
• OUT - System.out - e.g. OUT.println("message")
• AssertionResult - the assertion result

The script can check various aspects of the SampleResult . If an error is detected, the script should use AssertionResult.setFailureMessage("message") and AssertionResult.setFailure(true).

For futher details of all the methods available on each of the above variables, please check the Javadoc

8.5.12 Compare Assertion

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Parameters

8.5.7 HTML Assertion

The HTML Assertion allows the user to check the HTML syntax of the response data using JTidy.

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Parameters

18.5.3 Size Assertion

The Size Assertion tests that each response contains the right number of bytes in it. You can specify that the size be equal to, greater than, less than, or not equal to a given number of bytes.

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Parameters

18.5.13 SMIME Assertion

• bcmail-xxx.jar (BouncyCastle SMIME/CMS)
• bcprov-xxx.jar (BouncyCastle Provider)

If using the Mail Reader Sampler , please ensure that you select "Store the message using MIME (raw)" otherwise the Assertion won't be able to process the message correctly.

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Parameters

18.5.9 XML Schema Assertion

The XML Schema Assertion allows the user to validate a response against an XML Schema.

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Parameters

18.5.4 XML Assertion

The XML Assertion tests that the response data consists of a formally correct XML document. It does not validate the XML based on a DTD or schema or do any further validation.

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Parameters ¶

18.5.8 XPath Assertion

The XPath Assertion tests a document for well formedness, has the option of validating against a DTD, or putting the document through JTidy and testing for an XPath. If that XPath exists, the Assertion is true. Using "/" will match any well-formed document, and is the default XPath Expression. The assertion also supports boolean expressions, such as "count(//*error)=2". See http://www.w3.org/TR/xpath for more information on XPath.

• //title[text()='Text to match'] - matches <text>Text to match</text> anywhere in the response
• /title[text()='Text to match'] - matches <text>Text to match</text> at root level in the response

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Parameters

18.5.1 Response Assertion

The response assertion control panel lets you add pattern strings to be compared against various fields of the response. The pattern strings are:

• Contains, Matches: Perl5-style regular expressions
• Equals, Substring: plain text, case-sensitive

A summary of the pattern matching characters can be found at ORO Perl5 regular expressions.

You can also choose whether the strings will be expected to match the entire response, or if the response is only expected to contain the pattern. You can attach multiple assertions to any controller for additional flexibility.

Note that the pattern string should not include the enclosing delimiters, i.e. use Price: \d+ not /Price: \d+/ .

By default, the pattern is in multi-line mode, which means that the "." meta-character does not match newline. In multi-line mode, "^" and "$" match the start or end of any line anywhere within the string - not just the start and end of the entire string. Note that \s does match new-line. Case is also significant. To override these settings, one can use the extended regular expression syntax. For example:

    (?i) - ignore case     (?s) - treat target as single line, i.e. "." matches new-line     (?is) - both the above     These can be used anywhere within the expression and remain in effect until overriden.  e.g.     (?i)apple(?-i) Pie - matches "ApPLe Pie", but not "ApPLe pIe"     (?s)Apple.+?Pie - matches Apple followed by Pie, which may be on a subsequent line.     Apple(?s).+?Pie - same as above, but it's probably clearer to use the (?s) at the start.    

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Parameters

The pattern is a Perl5-style regular expression, but without the enclosing brackets.

Assertion Examples

 

Figure 14 - Test Plan

 

 

Figure 15 - Assertion Control Panel with Pattern

 

 

Figure 16 - Assertion Listener Results (Pass)

 

 

Figure 17 - Assertion Listener Results (Fail)

 

18.5.2 Duration Assertion

The Duration Assertion tests that each response was received within a given amount of time. Any response that takes longer than the given number of milliseconds (specified by the user) is marked as a failed response.

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Parameters

• Parameters - string containing the parameters as a single variable
• bsh.args - String array containing parameters, split on white-space

18.8.6 BSF PostProcessor

The BSF PostProcessor allows BSF script code to be applied after taking a sample.

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Parameters

The script (or file) is processed using the BSFEngine.exec() method, which does not return a value.

Before invoking the script, some variables are set up. Note that these are BSF variables - i.e. they can be used directly in the script.

• log - (Logger) - can be used to write to the log file
• Label - the String Label
• Filename - the script file name (if any)
• Parameters - the parameters (as a String)
• args[] - the parameters as a String array (split on whitespace)
• ctx - ( JMeterContext ) - gives access to the context
• vars - ( JMeterVariables ) - gives read/write access to variables: vars.get(key); vars.put(key,val); vars.putObject("OBJ1",new Object()); vars.getObject("OBJ2");
• props - (JMeterProperties - class java.util.Properties) - e.g. props.get("START.HMS"); props.put("PROP1","1234");
• prev - ( SampleResult ) - gives access to the previous SampleResult (if any)
• sampler - (Sampler)- gives access to the current sampler
• OUT - System.out - e.g. OUT.println("message")

For details of all the methods available on each of the above variables, please check the Javadoc

18.9.8 Debug PostProcessor

The Debug PostProcessor creates a subSample with the details of the previous Sampler properties, JMeter variables, properties and/or System Properties.

The values can be seen in the View Results Tree Listener Response Data pane.

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Parameters

18.8.8 JDBC PostProcessor

The JDBC PostProcessor enables you to run some SQL statement just after a sample has run. This can be useful if your JDBC Sample changes some data and you want to reset state to what it was before the JDBC sample run.

---

See Also:

• Test Plan using JDBC Pre/Post Processor

 

In the linked test plan,"JDBC PostProcessor" JDBC PostProcessor calls a stored procedure to delete from Database the Price Cut-Off that was created by PreProcessor.

 

JDBC PostProcessor

 

 

8.8.4 Result Status Action Handler

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Parameters

18.8.3 XPath Extractor

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Parameters

To allow for use in a ForEach Controller, the following variables are set on return:

• refName - set to first (or only) match; if no match, then set to default
• refName_matchNr - set to number of matches (may be 0)
• refName_n - n=1,2,3 etc. Set to the 1st, 2nd 3rd match etc.

Note: The next refName_n variable is set to null - e.g. if there are 2 matches, then refName_3 is set to null, and if there are no matches, then refName_1 is set to null.

XPath is query language targeted primarily for XSLT transformations. However it is usefull as generic query language for structured data too. See XPath Reference or XPath specification for more information. Here are few examples:

/html/head/title

extracts title element from HTML response

/book/page[2]

extracts 2nd page from a book

/book/page

extracts all pages from a book

//form[@name='countryForm']//select[@name='country']/option[text()='Czech Republic'])/@value

extracts value attribute of option element that match text 'Czech Republic' inside of select element with name attribute 'country' inside of form with name attribute 'countryForm'

18.8.1 Regular Expression Extractor

Allows the user to extract values from a server response using a Perl-type regular expression. As a post-processor, this element will execute after each Sample request in its scope, applying the regular expression, extracting the requested values, generate the template string, and store the result into the given variable name.

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Parameters

If the match number is set to a non-negative number, and a match occurs, the variables are set as follows:

• refName - the value of the template
• refName_gn, where n=0,1,2 - the groups for the match
• refName_g - the number of groups in the Regex (excluding 0)

• refName_g0
• refName_g1
• refName_g

If the match number is set to a negative number, then all the possible matches in the sampler data are processed. The variables are set as follows:

• refName_matchNr - the number of matches found; could be 0
• refName_n, where n = 1,2,3 etc - the strings as generated by the template
• refName_n_gm, where m=0,1,2 - the groups for match n
• refName - always set to the default value
• refName_gn - not set

See also Response Assertion for some examples of how to specify modifiers, and for further information on JMeter regular expressions.

• Parameters - string containing the parameters as a single variable
• bsh.args - String array containing parameters, split on white-space

18.7.8 BSF PreProcessor

The BSF PreProcessor allows BSF script code to be applied before taking a sample.

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Parameters

The script (or file) is processed using the BSFEngine.exec() method, which does not return a value.

The following BSF variables are set up for use by the script:

• log - (Logger) - can be used to write to the log file
• Label - the String Label
• Filename - the script file name (if any)
• Parameters - the parameters (as a String)
• args[] - the parameters as a String array (split on whitespace)
• ctx - ( JMeterContext ) - gives access to the context
• vars - ( JMeterVariables ) - gives read/write access to variables: vars.get(key); vars.put(key,val); vars.putObject("OBJ1",new Object()); vars.getObject("OBJ2");
• props - (JMeterProperties - class java.util.Properties) - e.g. props.get("START.HMS"); props.put("PROP1","1234");
• sampler - (Sampler)- gives access to the current sampler
• OUT - System.out - e.g. OUT.println("message")

For details of all the methods available on each of the above variables, please check the Javadoc

18.7.3 HTML Parameter Mask (DEPRECATED)

The HTML Parameter Mask is used to generate unique values for HTML arguments. By specifying the name of the parameter, a value prefix and suffix, and counter parameters, this modifier will generate values of the form " name=prefixcountersuffix ". Any HTTP Request that it modifies, it will replace any parameter with the same name or add the appropriate parameter to the requests list of arguments.

As an example, the username for a login script could be modified to send a series of values such as: 
user_1 
user_2 
user_3 
user_4, etc.

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Parameters

18.7.2 HTTP URL Re-writing Modifier

This modifier works similarly to the HTML Link Parser, except it has a specific purpose for which it is easier to use than the HTML Link Parser, and more efficient. For web applications that use URL Re-writing to store session ids instead of cookies, this element can be attached at the ThreadGroup level, much like the HTTP Cookie Manager . Simply give it the name of the session id parameter, and it will find it on the page and add the argument to every request of that ThreadGroup.

Alternatively, this modifier can be attached to select requests and it will modify only them. Clever users will even determine that this modifier can be used to grab values that elude the HTML Link Parser .

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Parameters

18.7.1 HTML Link Parser

This modifier parses HTML response from the server and extracts links and forms. A URL test sample that passes through this modifier will be examined to see if it "matches" any of the links or forms extracted from the immediately previous response. It would then replace the values in the URL test sample with appropriate values from the matching link or form. Perl-type regular expressions are used to find matches.

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Spidering Example

Consider a simple example: let's say you wanted JMeter to "spider" through your site, hitting link after link parsed from the HTML returned from your server (this is not actually the most useful thing to do, but it serves as a good example). You would create a Simple Controller , and add the "HTML Link Parser" to it. Then, create an HTTP Request, and set the domain to ".*", and the path likewise. This will cause your test sample to match with any link found on the returned pages. If you wanted to restrict the spidering to a particular domain, then change the domain value to the one you want. Then, only links to that domain will be followed.

Poll Example

A more useful example: given a web polling application, you might have a page with several poll options as radio buttons for the user to select. Let's say the values of the poll options are very dynamic - maybe user generated. If you wanted JMeter to test the poll, you could either create test samples with hardcoded values chosen, or you could let the HTML Link Parser parse the form, and insert a random poll option into your URL test sample. To do this, follow the above example, except, when configuring your Web Test controller's URL options, be sure to choose "POST" as the method. Put in hard-coded values for the domain, path, and any additional form parameters. Then, for the actual radio button parameter, put in the name (let's say it's called "poll_choice"), and then ".*" for the value of that parameter. When the modifier examines this URL test sample, it will find that it "matches" the poll form (and it shouldn't match any other form, given that you've specified all the other aspects of the URL test sample), and it will replace your form parameters with the matching parameters from the form. Since the regular expression ".*" will match with anything, the modifier will probably have a list of radio buttons to choose from. It will choose at random, and replace the value in your URL test sample. Each time through the test, a new random value will be chosen.

Figure 18 - Online Poll Example

18.7.9 JDBC PreProcessor

The JDBC PreProcessor enables you to run some SQL statement just before a sample runs. This can be useful if your JDBC Sample requires some data to be in DataBase and you cannot compute this in a setup Thread group. For details, see JDBC Request .

See the following Test plan:

See Also:

• Test Plan using JDBC Pre/Post Processor

In the linked test plan,"Create Price Cut-Off" JDBC PreProcessor calls a stored procedure to create a Price Cut-Off in Database, this one will be used by "Calculate Price cut off".

Create Price Cut-Off Preprocessor

18.4.14 User Defined Variables

The User Defined Variables element lets you define an initial set of variables , just as in the Test Plan . Note that all the UDV elements in a test plan - no matter where they are - are processed at the start. So you cannot reference variables which are defined as part of a test run, e.g. in a Post-Processor.

UDVs should not be used with functions that generate different results each time they are called. Only the result of the first function call will be saved in the variable. However, UDVs can be used with functions such as __P(), for example:

HOST      ${__P(host,localhost)}   

For defining variables during a test run, see User Parameters . UDVs are processed in the order they appear in the Plan, from top to bottom.

For simplicity, it is suggested that UDVs are placed only at the start of a Thread Group (or perhaps under the Test Plan itself).

Once the Test Plan and all UDVs have been processed, the resulting set of variables is copied to each thread to provide the initial set of variables.

If a runtime element such as a User Parameters Pre-Processor or Regular Expression Extractor defines a variable with the same name as one of the UDV variables, then this will replace the initial value, and all other test elements in the thread will see the updated value.

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Parameters

18.7.5 User Parameters

Allows the user to specify values for User Variables specific to individual threads.

User Variables can also be specified in the Test Plan but not specific to individual threads. This panel allows you to specify a series of values for any User Variable. For each thread, the variable will be assigned one of the values from the series in sequence. If there are more threads than values, the values get re-used. For example, this can be used to assign a distinct user id to be used by each thread. User variables can be referenced in any field of any jMeter Component.

The variable is specified by clicking the Add Variable button in the bottom of the panel and filling in the Variable name in the 'Name:' column. To add a new value to the series, click the 'Add User' button and fill in the desired value in the newly added column.

Values can be accessed in any test component in the same thread group, using the function syntax : ${variable}.

See also the CSV Data Set Config element, which is more suitable for large numbers of parameters

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Parameters

• Parameters - string containing the parameters as a single variable
• bsh.args - String array containing parameters, split on white-space

18.6.7 BSF Timer

The BSF Timer can be used to generate a delay using a BSF scripting language.

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Parameters

Before invoking the script, some variables are set up in the script interpreter:

• log - (Logger) - can be used to write to the log file
• ctx - ( JMeterContext ) - gives access to the context
• vars - ( JMeterVariables ) - gives read/write access to variables: vars.get(key); vars.put(key,val); vars.putObject("OBJ1",new Object());
• props - (JMeterProperties - class java.util.Properties) - e.g. props.get("START.HMS"); props.put("PROP1","1234");
• sampler - the current Sampler
• Label - the name of the Timer
• Filename - the file name (if any)
• OUT - System.out

For details of all the methods available on each of the above variables, please check the Javadoc

18.6.4 Constant Throughput Timer

This timer introduces variable pauses, calculated to keep the total throughput (in terms of samples per minute) as close as possible to a give figure. Of course the throughput will be lower if the server is not capable of handling it, or if other timers or time-consuming test elements prevent it.

N.B. although the Timer is called the Constant Throughput timer, the throughput value does not need to be constant. It can be defined in terms of a variable or function call, and the value can be changed during a test. The value can be changed in various ways:

• using a counter variable
• using a JavaScript or BeanShell function to provide a changing value
• using the remote BeanShell server to change a JMeter property

See Best Practices for further details. Note that the throughput value should not be changed too often during a test - it will take a while for the new value to take effect.

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18.6.9 Poisson Random Timer

This timer pauses each thread request for a random amount of time, with most of the time intervals ocurring near a particular value. The total delay is the sum of the Poisson distributed value, and the offset value.

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18.6.5 Synchronizing Timer

The purpose of the SyncTimer is to block threads until X number of threads have been blocked, and then they are all released at once. A SyncTimer can thus create large instant loads at various points of the test plan.

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18.6.3 Uniform Random Timer

This timer pauses each thread request for a random amount of time, with each time interval having the same probability of occurring. The total delay is the sum of the random value and the offset value.

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18.6.1 Constant Timer

If you want to have each thread pause for the same amount of time between requests, use this timer.

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Parameters

18.6.2 Gaussian Random Timer

This timer pauses each thread request for a random amount of time, with most of the time intervals ocurring near a particular value. The total delay is the sum of the Gaussian distributed value (with mean 0.0 and standard deviation 1.0) times the deviation value you specify, and the offset value. Another way to explain it, in Gaussian Random Timer, the variation around constant offset has a gaussian curve distribution.

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Parameters