摘要: java driver version: com.datastax.cassandra:cassandra-driver-core:3.1.2 概念 cassandra driver 与 cassandra cluster server 通过TCP协议进行异步通信。 首先,driver与cassan 阅读全文
posted @ 2016-12-08 14:58 RogerIs谭纶 阅读(203) 评论(0) 推荐(0) 编辑
摘要: Partitioner, which is a hash function to calculate the TOKEN() of row key. From cassandra 1.2, defaut partitioner is Murmur3Partitioner, of which the 阅读全文
posted @ 2016-12-02 10:03 RogerIs谭纶 阅读(139) 评论(0) 推荐(0) 编辑
摘要: modeling by query. secondary index is best on table that has many rows the contain fewer unique values (low cardinality). but, don't index on high-car 阅读全文
posted @ 2016-12-02 00:34 RogerIs谭纶 阅读(108) 评论(0) 推荐(0) 编辑
摘要: installation 推荐安装java native access提升casssandra内存的使用效率。 settings 修改所有节点的cassandra.yaml配置文件,位于/etc/cassandra, <install_location>/conf/ 修改cassandra-rack 阅读全文
posted @ 2016-11-21 11:19 RogerIs谭纶 阅读(133) 评论(0) 推荐(0) 编辑
摘要: 1. create keyspace 2. create table exchange, tick_date 两个字段作为row key / partition key; exchange, tick_date, symbol 3个字段作为(compound)primary key,复合主键,称之为 阅读全文
posted @ 2016-11-20 23:03 RogerIs谭纶 阅读(199) 评论(0) 推荐(0) 编辑
摘要: keyspace类似关系数据库的schema或database; cassandra可以支持column数量到2 billion; primary index 建立在primay key基础上。primary key有1个或多个column组成,但不管哪种情况,第一部分(通常用括号括起来)作为par 阅读全文
posted @ 2016-11-20 23:02 RogerIs谭纶 阅读(208) 评论(0) 推荐(0) 编辑
摘要: Series,一维数组,列表形式,例如: 阅读全文
posted @ 2016-11-06 16:57 RogerIs谭纶 阅读(73) 评论(0) 推荐(0) 编辑