cassandra初探

1 下载安装文件：http://cassandra.apache.org 目前的最新版本是1.0.8

2 设置cassandra_home环境变量：

右击我的电脑->高级->环境变量->新建->变量名输入：Cassandra_home变量值就将Cassandra 解压在目录复制到里面

3 启动cassandra服务器：bin目录下 cassandra.bat文件。

4 客户端连接服务器： bin 目录下 cassandra-cli.bat文件。双击该文件：

Starting Cassandra Client
Welcome to Cassandra CLI version 1.0.8

Type 'help;' or '?' for help.
Type 'quit;' or 'exit;' to quit.

[default@unknown] connect localhost/9160; （连接服务器） ----PAT：注意分号结尾，否则会一直出现 。。。而且不会去主动连接服务器
Connected to: "Test Cluster" on localhost/9160
[default@unknown] show cluster name; （显示集群名称）
Test Cluster
[default@unknown] show keyspaces; （显示keyspace）
Keyspace: system:
  Replication Strategy: org.apache.cassandra.locator.LocalStrategy
  Durable Writes: true
    Options: [replication_factor:1]
  Column Families:
    ColumnFamily: HintsColumnFamily (Super)
    "hinted handoff data"
      Key Validation Class: org.apache.cassandra.db.marshal.BytesType
      Default column value validator: org.apache.cassandra.db.marshal.BytesType
      Columns sorted by: org.apache.cassandra.db.marshal.BytesType/org.apache.ca
ssandra.db.marshal.BytesType
      Row cache size / save period in seconds / keys to save : 0.0/0/all
      Row Cache Provider: org.apache.cassandra.cache.ConcurrentLinkedHashCachePr
ovider
      Key cache size / save period in seconds: 0.01/0
      GC grace seconds: 0
      Compaction min/max thresholds: 4/32
      Read repair chance: 0.0
      Replicate on write: true
      Bloom Filter FP chance: default
      Built indexes: []
      Compaction Strategy: org.apache.cassandra.db.compaction.SizeTieredCompacti
onStrategy
    ColumnFamily: IndexInfo
    "indexes that have been completed"
      Key Validation Class: org.apache.cassandra.db.marshal.BytesType
      Default column value validator: org.apache.cassandra.db.marshal.BytesType
      Columns sorted by: org.apache.cassandra.db.marshal.UTF8Type
      Row cache size / save period in seconds / keys to save : 0.0/0/all
      Row Cache Provider: org.apache.cassandra.cache.ConcurrentLinkedHashCachePr
ovider
      Key cache size / save period in seconds: 0.01/0
      GC grace seconds: 0
      Compaction min/max thresholds: 4/32
      Read repair chance: 0.0
      Replicate on write: true
      Bloom Filter FP chance: default
      Built indexes: []
      Compaction Strategy: org.apache.cassandra.db.compaction.SizeTieredCompacti
onStrategy
    ColumnFamily: LocationInfo
    "persistent metadata for the local node"
      Key Validation Class: org.apache.cassandra.db.marshal.BytesType
      Default column value validator: org.apache.cassandra.db.marshal.BytesType
      Columns sorted by: org.apache.cassandra.db.marshal.BytesType
      Row cache size / save period in seconds / keys to save : 0.0/0/all
      Row Cache Provider: org.apache.cassandra.cache.ConcurrentLinkedHashCachePr
ovider
      Key cache size / save period in seconds: 0.01/0
      GC grace seconds: 0
      Compaction min/max thresholds: 4/32
      Read repair chance: 0.0
      Replicate on write: true
      Bloom Filter FP chance: default
      Built indexes: []
      Compaction Strategy: org.apache.cassandra.db.compaction.SizeTieredCompacti
onStrategy
    ColumnFamily: Migrations
    "individual schema mutations"
      Key Validation Class: org.apache.cassandra.db.marshal.BytesType
      Default column value validator: org.apache.cassandra.db.marshal.BytesType
      Columns sorted by: org.apache.cassandra.db.marshal.TimeUUIDType
      Row cache size / save period in seconds / keys to save : 0.0/0/all
      Row Cache Provider: org.apache.cassandra.cache.ConcurrentLinkedHashCachePr
ovider
      Key cache size / save period in seconds: 0.01/0
      GC grace seconds: 0
      Compaction min/max thresholds: 4/32
      Read repair chance: 0.0
      Replicate on write: true
      Bloom Filter FP chance: default
      Built indexes: []
      Compaction Strategy: org.apache.cassandra.db.compaction.SizeTieredCompacti
onStrategy
    ColumnFamily: NodeIdInfo
    "nodeId and their metadata"
      Key Validation Class: org.apache.cassandra.db.marshal.BytesType
      Default column value validator: org.apache.cassandra.db.marshal.BytesType
      Columns sorted by: org.apache.cassandra.db.marshal.TimeUUIDType
      Row cache size / save period in seconds / keys to save : 0.0/0/all
      Row Cache Provider: org.apache.cassandra.cache.ConcurrentLinkedHashCachePr
ovider
      Key cache size / save period in seconds: 0.01/0
      GC grace seconds: 0
      Compaction min/max thresholds: 4/32
      Read repair chance: 0.0
      Replicate on write: true
      Bloom Filter FP chance: default
      Built indexes: []
      Compaction Strategy: org.apache.cassandra.db.compaction.SizeTieredCompacti
onStrategy
    ColumnFamily: Schema
    "current state of the schema"
      Key Validation Class: org.apache.cassandra.db.marshal.BytesType
      Default column value validator: org.apache.cassandra.db.marshal.BytesType
      Columns sorted by: org.apache.cassandra.db.marshal.UTF8Type
      Row cache size / save period in seconds / keys to save : 0.0/0/all
      Row Cache Provider: org.apache.cassandra.cache.ConcurrentLinkedHashCachePr
ovider
      Key cache size / save period in seconds: 0.01/0
      GC grace seconds: 0
      Compaction min/max thresholds: 4/32
      Read repair chance: 0.0
      Replicate on write: true
      Bloom Filter FP chance: default
      Built indexes: []
      Compaction Strategy: org.apache.cassandra.db.compaction.SizeTieredCompacti
onStrategy
    ColumnFamily: Versions
    "server version information"
      Key Validation Class: org.apache.cassandra.db.marshal.UTF8Type
      Default column value validator: org.apache.cassandra.db.marshal.BytesType
      Columns sorted by: org.apache.cassandra.db.marshal.UTF8Type
      Row cache size / save period in seconds / keys to save : 0.0/0/all
      Row Cache Provider: org.apache.cassandra.cache.ConcurrentLinkedHashCachePr
ovider
      Key cache size / save period in seconds: 0.01/0
      GC grace seconds: 0
      Compaction min/max thresholds: 4/32
      Read repair chance: 0.0
      Replicate on write: true
      Bloom Filter FP chance: default
      Built indexes: []
      Column Metadata:
        Column Name: version
          Validation Class: org.apache.cassandra.db.marshal.UTF8Type
      Compaction Strategy: org.apache.cassandra.db.compaction.SizeTieredCompacti
onStrategy
[default@unknown] show api version;（显示API版本号）
19.20.0

（创建keyspace）-----PAT： 该命令为0.8以上的版本命令，和之前的略有不同，在使用的时候需要注意。

[default@unknown] create keyspace MyKeyspace with placement_strategy='org.apache
.cassandra.locator.SimpleStrategy' and strategy_options={replication_factor:1};
9c0b4b30-669d-11e1-0000-242d50cf1f9f
Waiting for schema agreement...
... schemas agree across the cluster

（进入新创建的keyspace）
[default@unknown] use MyKeyspace;
Authenticated to keyspace: MyKeyspace

 

（创建列族）

[default@MyKeyspace] create column family user
...     with comparator= UTF8Type
...      and key_validation_class=UTF8Type
...      and column_metadata = [
...     {column_name:fname,validation_class:UTF8Type}
...     {column_name:email,validation_class:UTF8Type}
...     ];
73ad74d0-66a5-11e1-0000-242d50cf1f9f
Waiting for schema agreement...
... schemas agree across the cluster

 

（向列族中写入数据）
[default@MyKeyspace] set user['ehewitt']['fname']='Eben';
Value inserted.
Elapsed time: 78 msec(s).
[default@MyKeyspace] set user['ehewitt']['email']='[email protected]';
Value inserted.
Elapsed time: 16 msec(s).

（计算插入的列数）
[default@MyKeyspace] count user['ehewitt'];
2 columns

（读取数据）
[default@MyKeyspace] get user['ehewitt'];
=> (column=email, [email protected], timestamp=1330939726609000)
=> (column=fname, value=Eben, timestamp=1330939699750000)
Returned 2 results.
Elapsed time: 47 msec(s).

（删除列）

[default@MyKeyspace] del user['ehewitt']['email'];
column removed.
[default@MyKeyspace] get user['ehewitt'];
=> (column=fname, value=Eben, timestamp=1330939699750000)
Returned 1 results.
Elapsed time: 0 msec(s).
[default@MyKeyspace]