title: JMeter load-testing : ClassNotFoundException: com.blazemeter.jmeter.threads.concurrency.ConcurrencyThreadGroup
body: <p>I'm trying non-GUI and distributed JMeter load-testing.</p>
  
  <p>Before I go distributed, I tested it locally. I installed JMeter on my laptop and setup a testplan targeting the system under test. I installed the plugin manager and install the concurrent thread plugin.
  I found my JMX file to be correct and working, so I decided to rollout the distributed setting.</p>
  
  <p>I setup three machines for load generation : load-1, load-2 and load-3. I installed JMeter as follow :
  <code>apt update ; apt upgrade</code> on all of them
  <code>apt install jmeter</code> on all of them
  copied the JARs located in /usr/share/jmeter/lib/ext of my laptop to all of them, in the same directory :</p>
  
  <pre><code>jmeter-plugins-casutg-2.1.jar
  jmeter-plugins-cmn-jmeter-0.3.jar
  jmeter-plugins-manager-0.11.jar
  </code></pre>
  
  <p>I started the JMeter server on two of them as follow :</p>
  
  <pre><code>export JMETER_HOME=/usr ; $JMETER_HOME/bin/jmeter-server -Djava.rmi.server.hostname=207.112.137.21
  export JMETER_HOME=/usr ; $JMETER_HOME/bin/jmeter-server -Djava.rmi.server.hostname=207.112.137.22
  </code></pre>
  
  <p>I use the third one to start the distributed testing as follow :</p>
  
  <pre><code>jmeter -n -t ~/JMeter_API_TestPlan.jmx -R207.112.137.21,207.112.137.22
  </code></pre>
  
  <p>The distrubuted setting seems to start correctly, but the thread start fail probably because of a class not being found :</p>
  
  <p>java.lang.ClassNotFoundException: com.blazemeter.jmeter.threads.concurrency.ConcurrencyThreadGroup (no security manager: RMI class loader disabled)</p>
  
  <p>A I missing a JAR or a configuration parameter ?</p>
  
  <p>The jmeter.log shows the following :</p>
  
  <pre><code>2017/06/23 09:34:33 INFO  - jmeter.util.JMeterUtils: Setting Locale to en_US 
  2017/06/23 09:34:33 INFO  - jmeter.JMeter: Loading user properties from: /usr/share/jmeter/bin/user.properties 
  2017/06/23 09:34:33 INFO  - jmeter.JMeter: Loading system properties from: /usr/share/jmeter/bin/system.properties 
  2017/06/23 09:34:33 INFO  - jmeter.JMeter: Copyright (c) 1998-2014 The Apache Software Foundation 
  2017/06/23 09:34:33 INFO  - jmeter.JMeter: Version 2.11.20151206 
  2017/06/23 09:34:33 INFO  - jmeter.JMeter: java.version=1.8.0_131 
  2017/06/23 09:34:33 INFO  - jmeter.JMeter: java.vm.name=OpenJDK 64-Bit Server VM 
  2017/06/23 09:34:33 INFO  - jmeter.JMeter: os.name=Linux 
  2017/06/23 09:34:33 INFO  - jmeter.JMeter: os.arch=amd64 
  2017/06/23 09:34:33 INFO  - jmeter.JMeter: os.version=4.4.0-64-generic 
  2017/06/23 09:34:33 INFO  - jmeter.JMeter: file.encoding=ANSI_X3.4-1968 
  2017/06/23 09:34:33 INFO  - jmeter.JMeter: Default Locale=English (United States) 
  2017/06/23 09:34:33 INFO  - jmeter.JMeter: JMeter  Locale=English (United States) 
  2017/06/23 09:34:33 INFO  - jmeter.JMeter: JMeterHome=/usr/share/jmeter 
  2017/06/23 09:34:33 INFO  - jmeter.JMeter: user.dir  =/usr/share/jmeter/lib/ext 
  2017/06/23 09:34:33 INFO  - jmeter.JMeter: PWD       =/usr/share/jmeter/lib/ext 
  2017/06/23 09:34:33 INFO  - jmeter.JMeter: IP: 127.0.1.1 Name: load-srv-1 FullName: load-srv-1.localdomain 
  2017/06/23 09:34:33 INFO  - jmeter.services.FileServer: Default base='/usr/share/jmeter/lib/ext' 
  2017/06/23 09:34:33 INFO  - jmeter.services.FileServer: Set new base='/home/ubuntu' 
  2017/06/23 09:34:33 INFO  - jmeter.JMeter: Loading file: /home/ubuntu/JMeter_API_TestPlan.jmx 
  2017/06/23 09:34:33 INFO  - jmeter.save.SaveService: Testplan (JMX) version: 2.2. Testlog (JTL) version: 2.2 
  2017/06/23 09:34:33 INFO  - jmeter.save.SaveService: Using SaveService properties file encoding UTF-8 
  2017/06/23 09:34:33 INFO  - jmeter.save.SaveService: Using SaveService properties version 2.6 
  2017/06/23 09:34:33 INFO  - jmeter.save.SaveService: Using SaveService properties file version 1554411 
  2017/06/23 09:34:33 INFO  - jmeter.save.SaveService: All converter versions present and correct 
  2017/06/23 09:34:33 INFO  - jmeter.protocol.http.control.CookieManager: Settings: Delete null: true Check: true Allow variable: true Save: false Prefix: COOKIE_ 
  2017/06/23 09:34:33 INFO  - jmeter.protocol.http.sampler.HTTPSamplerBase: Cannot find .className property for htmlParser, using default 
  2017/06/23 09:34:33 INFO  - jmeter.protocol.http.sampler.HTTPSamplerBase: Parser for text/html is  
  2017/06/23 09:34:33 INFO  - jmeter.protocol.http.sampler.HTTPSamplerBase: Parser for application/xhtml+xml is  
  2017/06/23 09:34:33 INFO  - jmeter.protocol.http.sampler.HTTPSamplerBase: Parser for application/xml is  
  2017/06/23 09:34:33 INFO  - jmeter.protocol.http.sampler.HTTPSamplerBase: Parser for text/xml is  
  2017/06/23 09:34:33 INFO  - jmeter.protocol.http.sampler.HTTPSamplerBase: Parser for text/vnd.wap.wml is org.apache.jmeter.protocol.http.parser.RegexpHTMLParser 
  2017/06/23 09:34:33 INFO  - jmeter.JMeter: Creating summariser &lt;summary&gt; 
  Creating summariser &lt;summary&gt;
  Created the tree successfully using /home/ubuntu/JMeter_API_TestPlan.jmx
  Configuring remote engine for 207.112.137.21
  2017/06/23 09:34:33 INFO  - jmeter.JMeter: Configuring remote engine for 207.112.137.21
  Using remote object: UnicastRef [liveRef: [endpoint:[207.112.137.21:33454](remote),objID:[-48d954a6:15cd4392e27:-7fff, 7098811430065264906]]]
  Configuring remote engine for 207.112.137.22
  2017/06/23 09:34:33 INFO  - jmeter.JMeter: Configuring remote engine for 207.112.137.22
  Using remote object: UnicastRef [liveRef: [endpoint:[207.112.137.22:39449](remote),objID:[-238f015b:15cd4393abf:-7fff, 6897427020325789391]]]
  Starting remote engines
  2017/06/23 09:34:33 INFO  - jmeter.JMeter: Starting remote engines 
  Starting the test @ Fri Jun 23 09:34:33 UTC 2017 (1498210473781)
  2017/06/23 09:34:33 INFO  - jmeter.engine.ClientJMeterEngine: running clientengine run method 
  2017/06/23 09:34:33 INFO  - jmeter.engine.util.CompoundVariable: Note: Function class names must contain the string: '.functions.' 
  2017/06/23 09:34:33 INFO  - jmeter.engine.util.CompoundVariable: Note: Function class names must not contain the string: '.gui.' 
  2017/06/23 09:34:33 INFO  - jmeter.samplers.SampleEvent: List of sample_variables: [] 
  2017/06/23 09:34:33 INFO  - jmeter.samplers.BatchSampleSender: Using batching (client settings) for this run. Thresholds: num=100, time=60000 
  2017/06/23 09:34:33 INFO  - jmeter.samplers.DataStrippingSampleSender: Using DataStrippingSampleSender for this run 
  2017/06/23 09:34:34 INFO  - jmeter.samplers.BatchSampleSender: Using batching (client settings) for this run. Thresholds: num=100, time=60000 
  2017/06/23 09:34:34 INFO  - jmeter.samplers.DataStrippingSampleSender: Using DataStrippingSampleSender for this run 
  2017/06/23 09:34:34 INFO  - jmeter.samplers.BatchSampleSender: Using batching (client settings) for this run. Thresholds: num=100, time=60000 
  2017/06/23 09:34:34 INFO  - jmeter.samplers.DataStrippingSampleSender: Using DataStrippingSampleSender for this run 
  2017/06/23 09:34:34 INFO  - jmeter.samplers.BatchSampleSender: Using batching (client settings) for this run. Thresholds: num=100, time=60000 
  2017/06/23 09:34:34 INFO  - jmeter.samplers.DataStrippingSampleSender: Using DataStrippingSampleSender for this run 
  2017/06/23 09:34:34 ERROR - jmeter.engine.ClientJMeterEngine: Error in rconfigure() method java.rmi.ServerException: RemoteException occurred in server thread; nested exception is: 
      java.rmi.UnmarshalException: error unmarshalling arguments; nested exception is: 
      java.lang.ClassNotFoundException: com.blazemeter.jmeter.threads.concurrency.ConcurrencyThreadGroup (no security manager: RMI class loader disabled) 
  2017/06/23 09:34:34 INFO  - jmeter.engine.ClientJMeterEngine: Interrupting RMI Reaper 
  Error in NonGUIDriver org.apache.jmeter.engine.JMeterEngineException: Error in rconfigure() method java.rmi.ServerException: RemoteException occurred in server thread; nested exception is: 
      java.rmi.UnmarshalException: error unmarshalling arguments; nested exception is: 
      java.lang.ClassNotFoundException: com.blazemeter.jmeter.threads.concurrency.ConcurrencyThreadGroup (no security manager: RMI class loader disabled)
  2017/06/23 09:34:34 ERROR - jmeter.JMeter: Error in NonGUIDriver org.apache.jmeter.engine.JMeterEngineException: Error in rconfigure() method java.rmi.ServerException: RemoteException occurred in server thread; nested exception is: 
      java.rmi.UnmarshalException: error unmarshalling arguments; nested exception is: 
      java.lang.ClassNotFoundException: com.blazemeter.jmeter.threads.concurrency.ConcurrencyThreadGroup (no security manager: RMI class loader disabled)
      at org.apache.jmeter.engine.ClientJMeterEngine.runTest(ClientJMeterEngine.java:156)
      at org.apache.jmeter.JMeter.runNonGui(JMeter.java:831)
      at org.apache.jmeter.JMeter.startNonGui(JMeter.java:733)
      at org.apache.jmeter.JMeter.start(JMeter.java:392)
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
      at java.lang.reflect.Method.invoke(Method.java:498)
      at org.apache.jmeter.NewDriver.main(NewDriver.java:259)
  Caused by: java.rmi.ServerException: RemoteException occurred in server thread; nested exception is: 
      java.rmi.UnmarshalException: error unmarshalling arguments; nested exception is: 
      java.lang.ClassNotFoundException: com.blazemeter.jmeter.threads.concurrency.ConcurrencyThreadGroup (no security manager: RMI class loader disabled)
      at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:377)
      at sun.rmi.transport.Transport$1.run(Transport.java:200)
      at sun.rmi.transport.Transport$1.run(Transport.java:197)
      at java.security.AccessController.doPrivileged(Native Method)
      at sun.rmi.transport.Transport.serviceCall(Transport.java:196)
      at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:568)
      at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:826)
      at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$0(TCPTransport.java:683)
      at java.security.AccessController.doPrivileged(Native Method)
      at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:682)
      at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
      at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
      at java.lang.Thread.run(Thread.java:748)
      at sun.rmi.transport.StreamRemoteCall.exceptionReceivedFromServer(StreamRemoteCall.java:276)
      at sun.rmi.transport.StreamRemoteCall.executeCall(StreamRemoteCall.java:253)
      at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:162)
      at org.apache.jmeter.engine.RemoteJMeterEngineImpl_Stub.rconfigure(Unknown Source)
      at org.apache.jmeter.engine.ClientJMeterEngine.runTest(ClientJMeterEngine.java:133)
      ... 8 more
  Caused by: java.rmi.UnmarshalException: error unmarshalling arguments; nested exception is: 
      java.lang.ClassNotFoundException: com.blazemeter.jmeter.threads.concurrency.ConcurrencyThreadGroup (no security manager: RMI class loader disabled)
      at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:337)
  </code></pre>
  
  <p>I'm running Ubuntu 16.04.2 LTS</p>