Unable to compute when histogram overflowed

[haydenxia]

After I deployed the mcac monitor(for 4 nodes cassandra cluster),I find cassandra system.log output warning information as follow frequently：
WARN [insights-6-1] 2022-02-15 10:48:29,236 UnixSocketClient.java:629 - Error reporting:
java.lang.IllegalStateException: Unable to compute when histogram overflowed
at org.apache.cassandra.metrics.DecayingEstimatedHistogramReservoir$EstimatedHistogramReservoirSnapshot.getMean(DecayingEstimatedHistogramReservoir.java:585)
at com.datastax.mcac.UnixSocketClient.writeMetric(UnixSocketClient.java:835)
at com.datastax.mcac.UnixSocketClient.access$500(UnixSocketClient.java:67)
at com.datastax.mcac.UnixSocketClient$2.lambda$onHistogramAdded$2(UnixSocketClient.java:531)
at com.datastax.mcac.UnixSocketClient.writeGroup(UnixSocketClient.java:618)
at com.datastax.mcac.UnixSocketClient.lambda$restartMetricReporting$1(UnixSocketClient.java:597)
at io.netty.util.concurrent.PromiseTask.runTask(PromiseTask.java:98)
at io.netty.util.concurrent.ScheduledFutureTask.run(ScheduledFutureTask.java:176)
at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:164)
at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:472)
at io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:384)
at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989)
at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
at java.lang.Thread.run(Thread.java:748)
Why?
Thank you for your help in advance.