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What it is

Thread group elements are the beginning points of any test plan. All controllers and samplers must be under a thread group. Other elements, e.g. Listeners, may be placed directly under the test plan, in which case they will apply to all the thread groups. As the name implies, the thread group element controls the number of threads JMeter will use to execute your test.

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1. Action to be taken after a Sampler error

• Continue (default)- ignore the error and continue with the test and run next sampler.

• Start Next Loop – ignore the error, start next loop and continue with the test

• Stop Thread – current thread exits

• Stop Test – the entire test is stopped at the end of any current samples. It means the pending samplers are still run until done.

• Stop Test Now – the entire test is stopped immediately. Any current samplers are interrupted if possible.

  
  

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2. Threads Properties:

• Set the Number of Threads (Users): Number of users to simulate.

• Set the Ramp-Up Period: The ramp-up period tells JMeter how long to take to “ramp-up” to the full number of threads chosen.If 10 threads are used, and the ramp-up period is 100 seconds, then JMeter will take 100 seconds to get all 10 threads up and running. Each thread will start 10 (100/10) seconds after the previous thread was begun. For example, the test started at 01:48:02, please see the illustration above:

• Set the Loop Count – the number of times to execute the test for each thread group. Alternatively, forever can be selected causing the test to run until manually stopped, or until meet the stop condition, such as stop test when has an error, or reach the End Time, run out of the Duration time, etc.If “Loop Forever” checkbox is checked, it means the request will be executed forever for each thread group, until the test has been stopped (by facing the error, reaching the End Time or Duration Time defined in Scheduler Configuration, see section below)By default, the thread group is configured to loop once through its elements.

• Delay Thread creation until needed: If selected, threads are created only when the appropriate proportion of the ramp-up time has elapsed. This is most appropriate for tests with a ramp-up time that is significantly longer than the time to execute a single thread. I.e. where earlier threads finish before later ones start.If not selected, all threads are created when the test starts (they then pause for the appropriate proportion of the ramp-up time). This is the original default and is appropriate for tests where threads are active throughout most of the test.

3. Scheduler Configuration

• Start Time: If the scheduler checkbox is selected, one can choose an absolute start time. When you start your test, JMeter will wait until the specified start time to begin testing. Note: the Startup Delay field over-rides this – see below.

• End Time: If the scheduler checkbox is selected, one can choose an absolute end time. When you start your test, JMeter will wait until the specified start time to begin testing, and it will stop at the specified end time. Note: the Duration field over-rides this – see below.

• Duration (seconds): If the scheduler checkbox is selected, one can choose a relative end time. JMeter will use this to calculate the End Time, and ignore the End Time value. When the test is run out of this time, it will stop and be using mode Stop Test as above.

• Startup delay (seconds): If the scheduler checkbox is selected, one can choose a relative startup delay. JMeter will use this to calculate the Start Time, and ignore the Start Time value.

例子：注意第一个线程的开始时间与第二个线程的开始时间，以及第一个和第二个线程的持续时间，最后留意从第三个线程开始，每个线程只执行了一次。

<?xml version="1.0" encoding="UTF-8"?>
<jmeterTestPlan version="1.2" properties="3.1" jmeter="3.1 r1770033">
  <hashTree>
    <TestPlan guiclass="TestPlanGui" testclass="TestPlan" testname="测试计划" enabled="true">
      <stringProp name="TestPlan.comments"></stringProp>
      <boolProp name="TestPlan.functional_mode">false</boolProp>
      <boolProp name="TestPlan.serialize_threadgroups">false</boolProp>
      <elementProp name="TestPlan.user_defined_variables" elementType="Arguments" guiclass="ArgumentsPanel" testclass="Arguments" testname="用户定义的变量" enabled="true">
        <collectionProp name="Arguments.arguments"/>
      </elementProp>
      <stringProp name="TestPlan.user_define_classpath"></stringProp>
    </TestPlan>
    <hashTree>
      <ThreadGroup guiclass="ThreadGroupGui" testclass="ThreadGroup" testname="线程组" enabled="true">
        <stringProp name="ThreadGroup.on_sample_error">continue</stringProp>
        <elementProp name="ThreadGroup.main_controller" elementType="LoopController" guiclass="LoopControlPanel" testclass="LoopController" testname="循环控制器" enabled="true">
          <boolProp name="LoopController.continue_forever">false</boolProp>
          <intProp name="LoopController.loops">-1</intProp>
        </elementProp>
        <stringProp name="ThreadGroup.num_threads">10</stringProp>
        <stringProp name="ThreadGroup.ramp_time">50</stringProp>
        <longProp name="ThreadGroup.start_time">1493024700000</longProp>
        <longProp name="ThreadGroup.end_time">1493024280000</longProp>
        <boolProp name="ThreadGroup.scheduler">true</boolProp>
        <stringProp name="ThreadGroup.duration">10</stringProp>
        <stringProp name="ThreadGroup.delay">5</stringProp>
      </ThreadGroup>
      <hashTree>
        <HTTPSamplerProxy guiclass="HttpTestSampleGui" testclass="HTTPSamplerProxy" testname="A" enabled="true">
          <elementProp name="HTTPsampler.Arguments" elementType="Arguments" guiclass="HTTPArgumentsPanel" testclass="Arguments" testname="用户定义的变量" enabled="true">
            <collectionProp name="Arguments.arguments"/>
          </elementProp>
          <stringProp name="HTTPSampler.domain">www.baidu.com</stringProp>
          <stringProp name="HTTPSampler.port"></stringProp>
          <stringProp name="HTTPSampler.connect_timeout"></stringProp>
          <stringProp name="HTTPSampler.response_timeout"></stringProp>
          <stringProp name="HTTPSampler.protocol"></stringProp>
          <stringProp name="HTTPSampler.contentEncoding"></stringProp>
          <stringProp name="HTTPSampler.path">/</stringProp>
          <stringProp name="HTTPSampler.method">GET</stringProp>
          <boolProp name="HTTPSampler.follow_redirects">true</boolProp>
          <boolProp name="HTTPSampler.auto_redirects">false</boolProp>
          <boolProp name="HTTPSampler.use_keepalive">true</boolProp>
          <boolProp name="HTTPSampler.DO_MULTIPART_POST">false</boolProp>
          <boolProp name="HTTPSampler.monitor">false</boolProp>
          <stringProp name="HTTPSampler.embedded_url_re"></stringProp>
        </HTTPSamplerProxy>
        <hashTree/>
        <HTTPSamplerProxy guiclass="HttpTestSampleGui" testclass="HTTPSamplerProxy" testname="B" enabled="false">
          <elementProp name="HTTPsampler.Arguments" elementType="Arguments" guiclass="HTTPArgumentsPanel" testclass="Arguments" testname="用户定义的变量" enabled="true">
            <collectionProp name="Arguments.arguments"/>
          </elementProp>
          <stringProp name="HTTPSampler.domain">www.zhibo8.cc</stringProp>
          <stringProp name="HTTPSampler.port"></stringProp>
          <stringProp name="HTTPSampler.connect_timeout"></stringProp>
          <stringProp name="HTTPSampler.response_timeout"></stringProp>
          <stringProp name="HTTPSampler.protocol"></stringProp>
          <stringProp name="HTTPSampler.contentEncoding"></stringProp>
          <stringProp name="HTTPSampler.path">/</stringProp>
          <stringProp name="HTTPSampler.method">GET</stringProp>
          <boolProp name="HTTPSampler.follow_redirects">true</boolProp>
          <boolProp name="HTTPSampler.auto_redirects">false</boolProp>
          <boolProp name="HTTPSampler.use_keepalive">true</boolProp>
          <boolProp name="HTTPSampler.DO_MULTIPART_POST">false</boolProp>
          <boolProp name="HTTPSampler.monitor">false</boolProp>
          <stringProp name="HTTPSampler.embedded_url_re"></stringProp>
        </HTTPSamplerProxy>
        <hashTree/>
        <HTTPSamplerProxy guiclass="HttpTestSampleGui" testclass="HTTPSamplerProxy" testname="C" enabled="false">
          <elementProp name="HTTPsampler.Arguments" elementType="Arguments" guiclass="HTTPArgumentsPanel" testclass="Arguments" testname="用户定义的变量" enabled="true">
            <collectionProp name="Arguments.arguments"/>
          </elementProp>
          <stringProp name="HTTPSampler.domain">jmeter.apache.org</stringProp>
          <stringProp name="HTTPSampler.port"></stringProp>
          <stringProp name="HTTPSampler.connect_timeout"></stringProp>
          <stringProp name="HTTPSampler.response_timeout"></stringProp>
          <stringProp name="HTTPSampler.protocol"></stringProp>
          <stringProp name="HTTPSampler.contentEncoding"></stringProp>
          <stringProp name="HTTPSampler.path">/</stringProp>
          <stringProp name="HTTPSampler.method">GET</stringProp>
          <boolProp name="HTTPSampler.follow_redirects">true</boolProp>
          <boolProp name="HTTPSampler.auto_redirects">false</boolProp>
          <boolProp name="HTTPSampler.use_keepalive">true</boolProp>
          <boolProp name="HTTPSampler.DO_MULTIPART_POST">false</boolProp>
          <boolProp name="HTTPSampler.monitor">false</boolProp>
          <stringProp name="HTTPSampler.embedded_url_re"></stringProp>
        </HTTPSamplerProxy>
        <hashTree/>
      </hashTree>
      <ResultCollector guiclass="ViewResultsFullVisualizer" testclass="ResultCollector" testname="察看结果树" enabled="true">
        <boolProp name="ResultCollector.error_logging">false</boolProp>
        <objProp>
          <name>saveConfig</name>
          <value class="SampleSaveConfiguration">
            <time>true</time>
            <latency>true</latency>
            <timestamp>true</timestamp>
            <success>true</success>
            <label>true</label>
            <code>true</code>
            <message>true</message>
            <threadName>true</threadName>
            <dataType>true</dataType>
            <encoding>false</encoding>
            <assertions>true</assertions>
            <subresults>true</subresults>
            <responseData>false</responseData>
            <samplerData>false</samplerData>
            <xml>true</xml>
            <fieldNames>true</fieldNames>
            <responseHeaders>false</responseHeaders>
            <requestHeaders>false</requestHeaders>
            <responseDataOnError>false</responseDataOnError>
            <saveAssertionResultsFailureMessage>true</saveAssertionResultsFailureMessage>
            <assertionsResultsToSave>0</assertionsResultsToSave>
            <bytes>true</bytes>
            <sentBytes>true</sentBytes>
            <threadCounts>true</threadCounts>
            <idleTime>true</idleTime>
            <connectTime>true</connectTime>
          </value>
        </objProp>
        <stringProp name="filename"></stringProp>
      </ResultCollector>
      <hashTree/>
    </hashTree>
  </hashTree>
</jmeterTestPlan>

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Validation Mode

This mode enables rapid validation of a Thread Group by running it with 1 thread, 1 iteration, no timers and no Startup delay set to 0.

The 3 first properties can be modified by setting in user.properties:

• testplan_validation.nb_threads_per_thread_group : Number of threads to use to validate a Thread Group, by default 1
• testplan_validation.ignore_timers : Ignore timers when validating the thread group of plan, by default 1
• testplan_validation.number_iterations : Number of iterations to use to validate a Thread Group