CODEWITHSUNDEEP
cassandra
chicchoc88
chicchoc88

Reputation: 61

Apache Cassandra : nodetool-h localhost-p 7199 cfstats

I start with cassandra and I want to know the size on disk of my column family. I search and I found the command : nodetool-h localhost-p 7199 cfstats

    Column Family: client
    SSTable count: 3
    Space used (live): 281774148
    Space used (total): 281774148
    Number of Keys (estimate): 1010176
    Memtable Columns Count: 0
    Memtable Data Size: 0
    Memtable Switch Count: 0
    Read Count: 0
    Read Latency: NaN ms.
    Write Count: 0
    Write Latency: NaN ms.
    Pending Tasks: 0
    Bloom Filter False Postives: 0
    Bloom Filter False Ratio: 0,00000
    Bloom Filter Space Used: 3752864
    Key cache capacity: 200000
    Key cache size: 0
    Key cache hit rate: NaN
    Row cache: disabled
    Compacted row minimum size: 216
    Compacted row maximum size: 310
    Compacted row mean size: 310

but I don't understand the result, so can you help me ?

Upvotes: 1

Views: 1486

Answers (1)

Richard
Richard

Reputation: 11110

The actual amount of space being used is 'Space used (total)'. This is measured in bytes.

The value of 'Space used (live)' is just for the files (SSTables) being used. It may be less than 'Space used (total)' because, during compaction, there will be unused parts of files being merged that can't be deleted yet. When a compaction finishes, it will be able to delete these duplicates and then 'Space used (total)' will decrease.

Note all these numbers are per node. If you want total usage then sum the numbers up for the cfstats output on each node.

Upvotes: 3

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