title: why jmeter not stop thread at Duraion time
body: <p>In my test plan, I create a Thread Group configured as below:<br/>
  1. Action to be taken after a Sampler error: Continue<br/>
  2. Number of Threads(users):10000<br/>
  3. Ramp-up Period(in seconds):1<br/>
  4. Loop Count:1<br/>
  5. Duration(seconds):2<br/>
  6. Startup delay(seconds):10<br/>
  <a href="https://i.stack.imgur.com/0Qsli.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/0Qsli.jpg" alt="enter image description here"></a>
  <br/>
  There is an Http Request Sampler in Thread Group.<br/>
  <a href="https://i.stack.imgur.com/qL1zq.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/qL1zq.jpg" alt="enter image description here"></a>
  <br/>
  After run the test plan, in jmeter.log <br/></p>
  
  <pre><code>2019-04-30 15:46:01,558 INFO o.a.j.e.StandardJMeterEngine: Starting ThreadGroup: 1 : Thread Group-WB
  2019-04-30 15:46:01,558 INFO o.a.j.e.StandardJMeterEngine: Starting 10000 threads for group Thread Group-WB.
  2019-04-30 15:46:01,558 INFO o.a.j.e.StandardJMeterEngine: Thread will continue on error
  2019-04-30 15:46:01,559 INFO o.a.j.t.ThreadGroup: Starting thread group... number=1 threads=10000 ramp-up=1 delayedStart=false
  2019-04-30 15:46:06,549 INFO o.a.j.t.ThreadGroup: Started thread group number 1
  2019-04-30 15:46:06,549 INFO o.a.j.e.StandardJMeterEngine: All thread groups have been started
  2019-04-30 15:46:11,559 INFO o.a.j.t.JMeterThread: Thread started: Thread Group-WB 1-1
  2019-04-30 15:46:11,562 INFO o.a.j.t.JMeterThread: Thread started: Thread Group-WB 1-2
  2019-04-30 15:46:11,614 INFO o.a.j.t.JMeterThread: Thread started: Thread Group-WB 1-67
  ...
  2019-04-30 15:46:15,541 INFO o.a.j.t.JMeterThread: Thread started: Thread Group-WB 1-5884
  2019-04-30 15:46:15,541 INFO o.a.j.t.JMeterThread: Thread started: Thread Group-WB 1-5890
  2019-04-30 15:46:15,541 INFO o.a.j.t.JMeterThread: Thread started: Thread Group-WB 1-5891
  ...
  2019-04-30 15:46:15,367 INFO o.a.j.t.JMeterThread: Thread started: Thread Group-WB 1-7239
  ...
  2019-04-30 15:46:21,913 INFO o.a.j.t.JMeterThread: Thread is done: Thread Group-WB 1-8506
  2019-04-30 15:46:21,912 INFO o.a.j.t.JMeterThread: Thread finished: Thread Group-WB 1-8505
  ...
  2019-04-30 15:46:16,872 INFO o.a.j.t.JMeterThread: Thread started: Thread Group-WB 1-8042
  2019-04-30 15:46:16,872 INFO o.a.j.t.JMeterThread: Thread started: Thread Group-WB 1-8041
  2019-04-30 15:46:18,767 INFO o.a.j.t.JMeterThread: Stopping because end time detected by thread: Thread Group-WB 1-7239
  2019-04-30 15:46:18,767 INFO o.a.j.t.JMeterThread: Thread is done: Thread Group-WB 1-7239
  2019-04-30 15:46:18,767 INFO o.a.j.t.JMeterThread: Thread finished: Thread Group-WB 1-7239
  ...
  2019-04-30 15:47:35,716 INFO o.a.j.t.JMeterThread: Thread is done: Thread Group-WB 1-9783
  2019-04-30 15:47:35,716 INFO o.a.j.t.JMeterThread: Thread finished: Thread Group-WB 1-9783
  2019-04-30 15:47:36,941 INFO o.a.j.t.JMeterThread: Stopping because end time detected by thread: Thread Group-WB 1-1037
  2019-04-30 15:47:36,942 INFO o.a.j.t.JMeterThread: Thread is done: Thread Group-WB 1-1037
  2019-04-30 15:47:36,942 INFO o.a.j.t.JMeterThread: Thread finished: Thread Group-WB 1-1037
  2019-04-30 15:47:36,944 INFO o.a.j.e.StandardJMeterEngine: Notifying test listeners of end of test
  2019-04-30 15:47:36,945 INFO o.a.j.g.u.JMeterMenuBar: setRunning(false, *local*)
  </code></pre>
  
  <p><br/>
  The first Thread Group-wisebuy 1-1 start at 2019-04-30 15:46:11,559<br/>
  I set Ramp-up Period as 1 second,why Thread Group-wisebuy 1-5891 started at 2019-04-30 15:46:15,541 ?<br/>
  <br/>
   I set Duration as 2 seconds,why Thread Group-wisebuy 1-7239 stopping at 2019-04-30 15:46:18,767 ?<br/>
  <br/></p>