Nodetool cfstats 中的 SStable 计数

Question

我最近开始向 cassandra 添加一些数据以进行性能测试，并查看 nodetool cfstats 并且即使插入大量数据后 sstable 计数仍然为 0。甚至 live 和 total 使用的空间仍然是 0。我错过了什么吗？

Keyspace: perftest
Read Count: 0
Read Latency: NaN ms.
Write Count: 126056
Write Latency: 0.028907025449006793 ms.
Pending Tasks: 0
    Column Family: items
    SSTable count: 0
    Space used (live): 0
    Space used (total): 0
    SSTable Compression Ratio: 0.0
    Number of Keys (estimate): 0
    Memtable Columns Count: 252112
    Memtable Data Size: 214612059
    Memtable Switch Count: 0
    Read Count: 0
    Read Latency: NaN ms.
    Write Count: 126056
    Write Latency: 0.029 ms.
    Pending Tasks: 0
    Bloom Filter False Positives: 0
    Bloom Filter False Ratio: 0.00000
    Bloom Filter Space Used: 0
    Compacted row minimum size: 0
    Compacted row maximum size: 0
    Compacted row mean size: 0
    Average live cells per slice (last five minutes): 0.0
    Average tombstones per slice (last five minutes): 0.0

Answer 1

您的 memtable 数据大小为 214612059 (214 MB)。这意味着数据还不足以导致它被刷新到磁盘。如果您插入更多，它将是，或者您可以使用nodetool flush.

列出的大小是磁盘上的大小，因此在刷新发生之前将为零。