Exception in thread "node2_MemtablePostFlush:1" java.util.concurrent.RejectedExecutionException: PerDiskMemtableFlushWriter_0 has shut down
	at org.apache.cassandra.concurrent.ThreadPoolExecutorBase.lambda$static$0(ThreadPoolExecutorBase.java:49)
	at org.apache.cassandra.concurrent.ThreadPoolExecutorJMXAdapter.lambda$rejectedExecutionHandler$0(ThreadPoolExecutorJMXAdapter.java:238)
	at java.base/java.util.concurrent.ThreadPoolExecutor.reject(ThreadPoolExecutor.java:833)
	at java.base/java.util.concurrent.ThreadPoolExecutor.execute(ThreadPoolExecutor.java:1365)
	at org.apache.cassandra.concurrent.ThreadPoolExecutorPlus.addTask(ThreadPoolExecutorPlus.java:50)
	at org.apache.cassandra.concurrent.ThreadPoolExecutorPlus.submit(ThreadPoolExecutorPlus.java:81)
	at org.apache.cassandra.db.ColumnFamilyStore$Flush.flushMemtable(ColumnFamilyStore.java:1309)
	at org.apache.cassandra.db.ColumnFamilyStore$Flush.run(ColumnFamilyStore.java:1260)
	at org.apache.cassandra.concurrent.ExecutionFailure$1.run(ExecutionFailure.java:133)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
	at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	at java.base/java.lang.Thread.run(Thread.java:840)
Exception in thread "node4_MemtablePostFlush:1" java.util.concurrent.RejectedExecutionException: MemtableReclaimMemory has shut down
	at org.apache.cassandra.concurrent.ThreadPoolExecutorBase.lambda$static$0(ThreadPoolExecutorBase.java:49)
	at org.apache.cassandra.concurrent.ThreadPoolExecutorJMXAdapter.lambda$rejectedExecutionHandler$0(ThreadPoolExecutorJMXAdapter.java:238)
	at java.base/java.util.concurrent.ThreadPoolExecutor.reject(ThreadPoolExecutor.java:833)
	at java.base/java.util.concurrent.ThreadPoolExecutor.execute(ThreadPoolExecutor.java:1365)
	at org.apache.cassandra.concurrent.ThreadPoolExecutorPlus.addTask(ThreadPoolExecutorPlus.java:50)
	at org.apache.cassandra.concurrent.ThreadPoolExecutorPlus.execute(ThreadPoolExecutorPlus.java:57)
	at org.apache.cassandra.utils.concurrent.ListenerList.safeExecute(ListenerList.java:166)
	at org.apache.cassandra.utils.concurrent.ListenerList.notifyListener(ListenerList.java:157)
	at org.apache.cassandra.utils.concurrent.ListenerList$RunnableWithExecutor.notifySelf(ListenerList.java:345)
	at org.apache.cassandra.utils.concurrent.ListenerList.lambda$notifyExclusive$0(ListenerList.java:124)
	at org.apache.cassandra.utils.concurrent.IntrusiveStack.forEach(IntrusiveStack.java:195)
	at org.apache.cassandra.utils.concurrent.ListenerList.notifyExclusive(ListenerList.java:124)
	at org.apache.cassandra.utils.concurrent.ListenerList.notify(ListenerList.java:96)
	at org.apache.cassandra.utils.concurrent.AsyncFuture.trySet(AsyncFuture.java:104)
	at org.apache.cassandra.utils.concurrent.AbstractFuture.trySuccess(AbstractFuture.java:143)
	at org.apache.cassandra.concurrent.FutureTask.run(FutureTask.java:71)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
	at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	at java.base/java.lang.Thread.run(Thread.java:840)