Cassandra カウンタを利用する方法

このドキュメントの内容は、以下の通りです。

• Counter Column Familyの作成
• インクリメントとデクリメント

Counter Column Familyの作成

create column family counterCF with default_validation_class=CounterColumnType and replicate_on_write=true and key_validation_class=UTF8Type;

インクリメントとデクリメント

[default@k1] incr counterCF ['access']['c1'];
Value incremented.
[default@k1] get counterCF ['access']['c1'];
=> (counter=c1, value=1)
Elapsed time: 132 msec(s).

[default@k1] get counterCF ['access']['c1'];
=> (counter=c1, value=1)
Elapsed time: 12 msec(s).
[default@k1] incr counterCF ['access']['c1'];
Value incremented.
[default@k1] get counterCF ['access']['c1'];
=> (counter=c1, value=2)
Elapsed time: 9 msec(s).
[default@k1] incr counterCF ['access']['c1'];
Value incremented.
[default@k1] get counterCF ['access']['c1'];
=> (counter=c1, value=3)
Elapsed time: 10 msec(s).

[default@k1] get counterCF ['access']['c1'];
=> (counter=c1, value=3)
Elapsed time: 10 msec(s).
[default@k1] incr counterCF ['access']['c1'] by 3;
Value incremented.
[default@k1] get counterCF ['access']['c1'];
=> (counter=c1, value=6)
Elapsed time: 8 msec(s).

[default@k1] incr counterCF ['access']['c2'] by 0;
Value incremented.
[default@k1] get counterCF ['access']['c2'] ;
=> (counter=c2, value=0)
Elapsed time: 9 msec(s).

[default@k1] get counterCF ['access']['c1'];
=> (counter=c1, value=6)
Elapsed time: 11 msec(s).
[default@k1] decr counterCF ['access']['c1'];
Value decremented.
[default@k1] get counterCF ['access']['c1'];
=> (counter=c1, value=5)
Elapsed time: 8 msec(s).