apache cassandra 3.11.2，12个节点，在运行nodetool cleanup时在一个节点中出现以下错误：

ERROR [CompactionExecutor:4996] 2019-04-10 16:09:43,938 CassandraDaemon.java:228 - Exception in thread Thread[CompactionExecutor:4996,1,main]
java.lang.AssertionError: null
        at org.apache.cassandra.io.compress.CompressionMetadata$Chunk.<init>(CompressionMetadata.java:474) ~[apache-cassandra-3.11.2.jar:3.11.2]
        at org.apache.cassandra.io.compress.CompressionMetadata.chunkFor(CompressionMetadata.java:239) ~[apache-cassandra-3.11.2.jar:3.11.2]
        at org.apache.cassandra.io.util.MmappedRegions.updateState(MmappedRegions.java:163) ~[apache-cassandra-3.11.2.jar:3.11.2]
        at org.apache.cassandra.io.util.MmappedRegions.<init>(MmappedRegions.java:73) ~[apache-cassandra-3.11.2.jar:3.11.2]
        at org.apache.cassandra.io.util.MmappedRegions.<init>(MmappedRegions.java:61) ~[apache-cassandra-3.11.2.jar:3.11.2]
        at org.apache.cassandra.io.util.MmappedRegions.map(MmappedRegions.java:104) ~[apache-cassandra-3.11.2.jar:3.11.2]
        at org.apache.cassandra.io.util.FileHandle$Builder.complete(FileHandle.java:362) ~[apache-cassandra-3.11.2.jar:3.11.2]
        at org.apache.cassandra.io.sstable.format.big.BigTableWriter.openEarly(BigTableWriter.java:290) ~[apache-cassandra-3.11.2.jar:3.11.2]
        at org.apache.cassandra.io.sstable.SSTableRewriter.maybeReopenEarly(SSTableRewriter.java:179) ~[apache-cassandra-3.11.2.jar:3.11.2]
        at org.apache.cassandra.io.sstable.SSTableRewriter.append(SSTableRewriter.java:134) ~[apache-cassandra-3.11.2.jar:3.11.2]
        at org.apache.cassandra.db.compaction.CompactionManager.doCleanupOne(CompactionManager.java:1137) ~[apache-cassandra-3.11.2.jar:3.11.2]
        at org.apache.cassandra.db.compaction.CompactionManager.access$400(CompactionManager.java:86) ~[apache-cassandra-3.11.2.jar:3.11.2]
        at org.apache.cassandra.db.compaction.CompactionManager$6.execute(CompactionManager.java:475) ~[apache-cassandra-3.11.2.jar:3.11.2]
        at org.apache.cassandra.db.compaction.CompactionManager$2.call(CompactionManager.java:322) ~[apache-cassandra-3.11.2.jar:3.11.2]
        at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[na:1.8.0_191]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) ~[na:1.8.0_191]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_191]
        at org.apache.cassandra.concurrent.NamedThreadFactory.lambda$threadLocalDeallocator$0(NamedThreadFactory.java:81) [apache-cassandra-3.11.2.jar:3.11.2]
        at java.lang.Thread.run(Thread.java:748) ~[na:1.8.0_191]
ERROR [Reference-Reaper:1] 2019-04-10 16:10:01,613 Ref.java:224 - LEAK DETECTED: a reference (org.apache.cassandra.utils.concurrent.Ref$State@6bfdb59e) to class org.apache.cassandra.io.util.FileHandle$Cleanup@1698322065:/data/cassandra/data_files/path/mc-135-big-Index.db was not released before the reference was garbage collected
ERROR [Reference-Reaper:1] 2019-04-10 16:10:01,626 Ref.java:224 - LEAK DETECTED: a reference (org.apache.cassandra.utils.concurrent.Ref$State@6105deee) to class org.apache.cassandra.io.util.MmappedRegions$Tidier@604462250:/data/cassandra/data_files/path/mc-135-big-Data.db was not released before the reference was garbage collected
ERROR [Reference-Reaper:1] 2019-04-10 16:10:01,626 Ref.java:224 - LEAK DETECTED: a reference (org.apache.cassandra.utils.concurrent.Ref$State@22504cf1) to class org.apache.cassandra.utils.concurrent.WrappedSharedCloseable$Tidy@359209204:[Memory@[0..44), Memory@[0..4c8)] was not released before the reference was garbage collected
ERROR [Reference-Reaper:1] 2019-04-10 16:10:01,627 Ref.java:224 - LEAK DETECTED: a reference (org.apache.cassandra.utils.concurrent.Ref$State@5ad45619) to class org.apache.cassandra.io.util.SafeMemory$MemoryTidy@1143514085:Memory@[7eaa3bdf4000..7eaa3bdf7200) was not released before the reference was garbage collected

我们需要做什么？是否用新节点替换此节点？这个错误是什么意思？我们在所有节点中的nodetool修复成功完成后运行清理。