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NoSpamLogger.java Maximum memory usage reached Cassandra

in cassandra Maximum memory usage reached (536870912 bytes), cannot allocate chunk of 1048576 bytes

但是他们并没有问同样的事情。我要彻底了解此消息的含义？目前看来，这并没有影响我的等待时间。

我做了一个nodetool cfstats

            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

延迟对我来说看起来不错。

我也做了直方图

百分位SSTables WriteLatency ReadLatency PartitionSize 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

统计数据对我来说不错！那卡桑德拉在抱怨什么呢？

Answer 1

此jira中的评论有一个解释：https://issues.apache.org/jira/browse/CASSANDRA-12221

报价：

邓伟添加了一条评论-16年7月18日05:01

请参阅CASSANDRA-5661。这是一个限制RandomAccessReader使用的堆外内存量的上限，如果需要，您可以在cassandra.yaml中通过file_cache_size_in_mb更改限制。

Cassandra-达到最大内存使用量（128.000MiB）无法分配1.000 MiB的块，这是什么意思？

1 个答案: