我已将具有2个节点的DSE群集从5.0.7升级到6.7.3。使用nodetool状态升级后，显示两个节点均为“ UP NORMAL”，每个节点上的负载约为75 GB，并且群集适用于具有读写功能的应用程序。但在期间出现错误
每10秒钟观察一次system.log文件中的异常
WARN [OptionalTasks:1] 2019-07-18 08:20:14,495 CassandraRoleManager.java:386 - CassandraRoleManager skipped default role setup: some nodes were not ready
INFO [OptionalTasks:1] 2019-07-18 08:20:14,495 CassandraRoleManager.java:432 - Setup task failed with error, rescheduling
org.apache.cassandra.exceptions.UnavailableException: Cannot achieve consistency level ONE
at org.apache.cassandra.db.ConsistencyLevel.assureSufficientLiveNodes(ConsistencyLevel.java:392)
at org.apache.cassandra.service.AbstractReadExecutor.getReadExecutor(AbstractReadExecutor.java:214)
at org.apache.cassandra.service.AbstractReadExecutor.getReadExecutor(AbstractReadExecutor.java:190)
at org.apache.cassandra.service.StorageProxy$SinglePartitionReadLifecycle.<init>(StorageProxy.java:1541)
at org.apache.cassandra.service.StorageProxy.fetchRows(StorageProxy.java:1524)
at org.apache.cassandra.service.StorageProxy.readRegular(StorageProxy.java:1447)
at org.apache.cassandra.service.StorageProxy.read(StorageProxy.java:1325)
at org.apache.cassandra.db.SinglePartitionReadCommand$Group.execute(SinglePartitionReadCommand.java:1274)
at org.apache.cassandra.cql3.statements.SelectStatement.execute(SelectStatement.java:366)
at org.apache.cassandra.cql3.statements.SelectStatement.execute(SelectStatement.java:574)
at org.apache.cassandra.cql3.statements.SelectStatement.execute(SelectStatement.java:307)
at org.apache.cassandra.cql3.QueryProcessor.lambda$processStatement$4(QueryProcessor.java:256)
at io.reactivex.internal.operators.single.SingleDefer.subscribeActual(SingleDefer.java:36)
at io.reactivex.Single.subscribe(Single.java:2700)
at io.reactivex.internal.operators.single.SingleMap.subscribeActual(SingleMap.java:34)
at io.reactivex.Single.subscribe(Single.java:2700)
at io.reactivex.Single.blockingGet(Single.java:2153)
at org.apache.cassandra.concurrent.TPCUtils.blockingGet(TPCUtils.java:75)
at org.apache.cassandra.cql3.QueryProcessor.processBlocking(QueryProcessor.java:352)
at org.apache.cassandra.auth.CassandraRoleManager.hasExistingRoles(CassandraRoleManager.java:396)
at org.apache.cassandra.auth.CassandraRoleManager.setupDefaultRole(CassandraRoleManager.java:370)
at org.apache.cassandra.auth.CassandraRoleManager.doSetupDefaultRole(CassandraRoleManager.java:428)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at org.apache.cassandra.concurrent.NamedThreadFactory.lambda$threadLocalDeallocator$0(NamedThreadFactory.java:79)
at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
at java.lang.Thread.run(Thread.java:748)