Cassandra - 每个切片的平均墓碑与每个切片的平均活细胞相同

Question

SSTable count: 2
    Space used (live): 66483
    Space used (total): 66483
    Space used by snapshots (total): 0
    Off heap memory used (total): 740
    SSTable Compression Ratio: 0.20385198102497917
    Number of partitions (estimate): 698
    Memtable cell count: 238
    Memtable data size: 124636
    Memtable off heap memory used: 0
    Memtable switch count: 1
    Local read count: 6360
    Local read latency: 0.049 ms
    Local write count: 679
    Local write latency: 0.015 ms
    Pending flushes: 0
    Percent repaired: 0.0
    Bloom filter false positives: 2
    Bloom filter false ratio: 0.00000
    Bloom filter space used: 608
    Bloom filter off heap memory used: 592
    Index summary off heap memory used: 100
    Compression metadata off heap memory used: 48
    Compacted partition minimum bytes: 216
    Compacted partition maximum bytes: 924
    Compacted partition mean bytes: 550
    Average live cells per slice (last five minutes): 1.0
    Maximum live cells per slice (last five minutes): 1
    Average tombstones per slice (last five minutes): 1.0
    Maximum tombstones per slice (last five minutes): 1
    Dropped Mutations: 0

即使没有墓碑（我使用sstablemetada和https://github.com/tolbertam/sstable-tools检查过它），它说它总是读取一块墓碑？

我插入时设置了数据。但是ttls是1年，刚开始服务。所以，它不能因为记录已过期。

是否有任何其他原因它总是读取一个墓碑。

注意：插入我使用的记录（如果不存在）。不确定是否与任何事情有关。

编辑：添加我的架构定义

CREATE TABLE items(
id bigint PRIMARY KEY,
data blob,
) WITH compaction = {
'compaction_window_size': '1',
'compaction_window_unit': 'DAYS',
'class': 
'org.apache.cassandra.db.compaction.TimeWindowCompactionStrategy'
};