Cassandra-已达到最大内存使用量（128.000MiB）无法分配1.000MiB块，这意味着什么？

还有另外两个相关职位

但他们的要求并不完全相同。我要求彻底理解这个信息的含义是什么？目前它似乎没有影响我的延迟

我做了一个

nodetoolcfstats

            SSTable count: 5
            Space used (live): 1182782029
            Space used (total): 1182782029
            Space used by snapshots (total): 0
            Off heap memory used (total): 802011
            SSTable Compression Ratio: 0.17875764458149868
            Number of keys (estimate): 34
            Memtable cell count: 33607
            Memtable data size: 5590408
            Memtable off heap memory used: 0
            Memtable switch count: 902
            Local read count: 4689
            Local read latency: NaN ms
            Local write count: 51592342
            Local write latency: 0.035 ms
            Pending flushes: 0
            Percent repaired: 0.0
            Bloom filter false positives: 0
            Bloom filter false ratio: 0.00000
            Bloom filter space used: 120
            Bloom filter off heap memory used: 80
            Index summary off heap memory used: 291
            Compression metadata off heap memory used: 801640
            Compacted partition minimum bytes: 447
            Compacted partition maximum bytes: 2874382626
            Compacted partition mean bytes: 164195240
            Average live cells per slice (last five minutes): NaN
            Maximum live cells per slice (last five minutes): 0
            Average tombstones per slice (last five minutes): NaN
            Maximum tombstones per slice (last five minutes): 0
            Dropped Mutations: 0

对我来说，延迟看起来很好

我还做了柱状图

• 百分位SSTables写相关性ReadLatency分区大小CellCount
• 50%0.00 35.43 0.00 1629722 35425
• 75%0.00 42.51 0.00 129557750 2346799
• 95%0.00 61.21 0.00 668489532 14530764
• 98%0.00 73.46 0.00 2874382626 52066354
• 99%0.00 88.15 0.00 2874382626 52066354
• 最低0.00 11.87 0.00 447 11
• 最大0.00 785.94 0.00 2874382626 52066354

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这些数据在我看来很好！那么卡桑德拉在抱怨什么呢？

这篇文章中的评论有一个解释：

引述：

邓伟补充了一条评论-18/Jul/16 05:01

见CASSANDRA-5661。这是一个限制RandomAccessReader使用的堆外内存量的上限，如果需要，可以通过cassandra.yaml中的文件\u cache\u size\u in_mb来更改限制