AssertionError: Concurrent test failed
....


E         ===== Using optimized driver!!! =====
E         Connected to cluster: test, max pending requests per connection null, max connections per host 8
E         Datatacenter: datacenter1; Host: /127.0.65.1; Rack: rack1
E         Datatacenter: datacenter1; Host: /127.0.65.2; Rack: rack1
E         Created keyspaces. Sleeping 1s for propagation.
E         Sleeping 2s...
E         Warming up WRITE with 50000 iterations...
E         com.datastax.driver.core.exceptions.TransportException: [127.0.65.2/127.0.65.2:9042] Connection has been closed
E         	at com.datastax.driver.core.exceptions.TransportException.copy(TransportException.java:38)
E         	at com.datastax.driver.core.exceptions.TransportException.copy(TransportException.java:24)
E         	at com.datastax.driver.core.DriverThrowables.propagateCause(DriverThrowables.java:35)
E         	at com.datastax.driver.core.AbstractSession.prepare(AbstractSession.java:86)
E         	at org.apache.cassandra.stress.util.JavaDriverClient.prepare(JavaDriverClient.java:123)
E         	at org.apache.cassandra.stress.operations.predefined.CqlOperation$JavaDriverWrapper.createPreparedStatement(CqlOperation.java:318)
E         	at org.apache.cassandra.stress.operations.predefined.CqlOperation.run(CqlOperation.java:77)
E         	at org.apache.cassandra.stress.operations.predefined.CqlOperation.run(CqlOperation.java:109)
E         	at org.apache.cassandra.stress.operations.predefined.CqlOperation.run(CqlOperation.java:264)
E         	at org.apache.cassandra.stress.StressAction$Consumer.run(StressAction.java:473)
E         Caused by: com.datastax.driver.core.exceptions.TransportException: [127.0.65.2/127.0.65.2:9042] Connection has been closed
E         	at com.datastax.driver.core.Connection$ConnectionCloseFuture.force(Connection.java:1737)
E         	at com.datastax.driver.core.Connection$ConnectionCloseFuture.force(Connection.java:1718)
E         	at com.datastax.driver.core.Connection.defunct(Connection.java:815)
E         	at com.datastax.driver.core.Connection$Dispatcher.exceptionCaught(Connection.java:1631)
E         	at com.datastax.shaded.netty.channel.AbstractChannelHandlerContext.invokeExceptionCaught(AbstractChannelHandlerContext.java:302)
E         	at com.datastax.shaded.netty.channel.AbstractChannelHandlerContext.invokeExceptionCaught(AbstractChannelHandlerContext.java:281)
E         	at com.datastax.shaded.netty.channel.AbstractChannelHandlerContext.fireExceptionCaught(AbstractChannelHandlerContext.java:273)
E         	at com.datastax.shaded.netty.channel.DefaultChannelPipeline$HeadContext.exceptionCaught(DefaultChannelPipeline.java:1377)
E         	at com.datastax.shaded.netty.channel.AbstractChannelHandlerContext.invokeExceptionCaught(AbstractChannelHandlerContext.java:302)
E         	at com.datastax.shaded.netty.channel.AbstractChannelHandlerContext.invokeExceptionCaught(AbstractChannelHandlerContext.java:281)
E         	at com.datastax.shaded.netty.channel.DefaultChannelPipeline.fireExceptionCaught(DefaultChannelPipeline.java:907)
E         	at com.datastax.shaded.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.handleReadException(AbstractNioByteChannel.java:125)
E         	at com.datastax.shaded.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:177)
E         	at com.datastax.shaded.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:722)
E         	at com.datastax.shaded.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:658)
E         	at com.datastax.shaded.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:584)
E         	at com.datastax.shaded.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:496)
E         	at com.datastax.shaded.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:986)
E         	at com.datastax.shaded.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
E         	at com.datastax.shaded.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
E         	at java.base/java.lang.Thread.run(Thread.java:829)
E         ; 
E         stderr: java.lang.RuntimeException: Failed to execute warmup
E         	at org.apache.cassandra.stress.StressAction.warmup(StressAction.java:128)
E         	at org.apache.cassandra.stress.StressAction.run(StressAction.java:71)
E         	at org.apache.cassandra.stress.Stress.run(Stress.java:143)
E         	at org.apache.cassandra.stress.Stress.main(Stress.java:62)
E         
E                                                     [restart                                                                                                             ]
E         
E       assert not True
E        +  where True = <nodetool_additional_test.TestNodetool object at 0x7f3fbb4df1d0>.concurrent_test_fail

nodetool_additional_test.py:1984: AssertionError