Cassandra入门

介绍:
百度一下，开源神器

安装
教程参考
下载 解压 运行 操作记录 中途升级了jdk到1.8
bin目录下并没有bin/cassandra-cli 这个文件。
所以只能研究cqlsh 就涉及到要python了。

  wget http://download.oracle.com/otn-pub/java/jdk/8u101-b13/jdk-8u101-linux-x64.tar.gz?AuthParam=1472798727_b12d21e489365bb3f451f4967df7d694

 jdk1.8 
http://www.oracle.com/technetwork/java/javase/downloads/index-jsp-138363.html

注意url是windows下点下载后复制的 

  288  ll
  289  mv jdk-8u101-linux-x64.tar.gz\?AuthParam\=1472798727_b12d21e489365bb3f451f4967df7d694  jdk.tar.gz
  290  ll
  291  tar -zxvf jdk.tar.gz  -C /usr/local/jdk8
  292  mkdir -p /usr/local/jdk8
  293  tar -zxvf jdk.tar.gz  -C /usr/local/jdk8
  294  cd /usr/local/jdk8/
  295  ll
  296  cd jdk1.8.0_101/
  297  pwd
  298  vim /etc/profile
  299  source /etc/profile
  300  java -version
  301  echo $JAVA_HOME
  302  java -version
  303  source /etc/profile
  304  java -version
  305  vim ~/.bashrc 
  306  reboot
  307  java -version
  308  su cassandra
  309  cd /data/cassandra/
  310  ll
  311  cd apache-cassandra-3.7
  312  ll
  313  cd bin/
  314  ll
  315  ./cqlsh
  316  ps -aux |grep cassandra 
  317  ps |grep cassandra
  318  reboot
  319  chown cassandra:cassandra /usr/local/cassandra-3.7/
  320  cd /usr/local/cassandra-3.7/
  321  ll
  322  chown cassandra:cassandra /usr/local/cassandra-3.7
  323  ll
  324  chown cassandra:cassandra /usr/local/cassandra-3.7
  325  ll
  326  chown -R  cassandra:cassandra /usr/local/cassandra-3.7
  327  ll
  328  chmod -R 777 /usr/local/cassandra-3.7
  329  ll
  330  bin/cassandra-cli --host localhost
  331  cd bin/
  332  ll
  333  ./cassandra -cli --host localhost
  334  ./nodetool status
  335  ./cqlsh

启动

[root@template bin]# ./cassandra
Running Cassandra as root user or group is not recommended - please start Cassandra using a different system user.
If you really want to force running Cassandra as root, use -R command line option.
这里要新建个用户运行
 270  useradd -d /usr/cassandra -m cassandra
 271  passwd cassandra
[root@template bin]# su cassandra
[cassandra@template bin]$ ./cassandra

运行测试的时候
bin/cqlsh localhost
提示
No appropriate python interpreter found.
centos6上需要安装python环境
参考此篇
安装教程
参考此篇

安装完成后测试 bin/cqlsh

[root@template cassandra-3.7]# pwd
/usr/local/cassandra-3.7
[root@template cassandra-3.7]# bin/cqlsh localhost
Connection error: ('Unable to connect to any servers', {'localhost': error(111, "Tried connecting to [('::1', 9042, 0, 0), ('127.0.0.1', 9042)]. Last error: Connection refused")})

原来是之前前台运行的 那个窗口超时自动关闭了
重新启动了下
再试

[root@template cassandra-3.7]# bin/cqlsh localhost
Connected to Test Cluster at localhost:9042.
[cqlsh 5.0.1 | Cassandra 3.7 | CQL spec 3.4.2 | Native protocol v4]
Use HELP for help.
cqlsh> 

哟霍，成功了！cqlsh终于能用了！
来试试查询

cqlsh> SELECT cluster_name, listen_address FROM system.local;

 cluster_name | listen_address
--------------+----------------
 Test Cluster |      127.0.0.1

(1 rows)
cqlsh> 

查了下cql的语法
参考此篇
sql cql
部分摘抄

//显示keyspace
cqlsh> describe keyspaces;
//创建keyspace
cqlsh> CREATE KEYSPACE IF NOT EXISTS myCas WITH REPLICATION = {'class': 'SimpleStrategy','replication_factor':1};
创建名字为mycas的keyspace.我们使用刚创建的keyspace:

//选择keyspace
cqlsh> use mycas
   ... ;
cqlsh:mycas> create table user(
         ... id int,
         ... user_name varchar,
         ... primary key(id) );
cqlsh:mycas> 
//向表中添加数据
cqlsh> use mycas;
cqlsh:mycas> INSERT INTO users (id,user_name) VALUES (1,'zhangsan');
cqlsh:mycas> select * from users;

 id | user_name
----+-----------
  1 |  zhangsan

插入数据的时候报错了

cqlsh:mycas> INSERT INTO users (id,user_name) VALUES (1,'root');    
InvalidRequest: code=2200 [Invalid query] message="unconfigured table users"

表名错了 user 非users

[root@template bin]# ./cqlsh localhost
Connected to Test Cluster at localhost:9042.
[cqlsh 5.0.1 | Cassandra 3.7 | CQL spec 3.4.2 | Native protocol v4]
Use HELP for help.
cqlsh> SELECT cluster_name, listen_address FROM system.local;

 cluster_name | listen_address
--------------+----------------
 Test Cluster |      127.0.0.1

(1 rows)
cqlsh> select * from mycas.user;

 id | user_name
----+-----------

(0 rows)
cqlsh> use mycas;
cqlsh:mycas> insert into user(id,user_name) values (1,'root');
cqlsh:mycas> select * from user;

 id | user_name
----+-----------
  1 |      root

(1 rows)
cqlsh:mycas> 
cqlsh:mycas> select * from mycas.user;

 id | user_name
----+-----------
  1 |      root

(1 rows)
cqlsh:mycas> 

没有使用keyspace时查询的时候要加keyspace点表名

—————–2017年6月8日16:55:05—————–
在高性能计算机上安装遇到过的坑记录

配置环境变量时 等号两边不要有空格

报错信息
INFO  [main] 2017-06-08 16:40:35,888 YamlConfigurationLoader.java:89 - Configuration location: file:/data02/home/zwh/cassandra/170cassandra/apache-cassandra-3.10/conf/cassandra.yaml
Exception (org.apache.cassandra.exceptions.ConfigurationException) encountered during startup: Invalid yaml: file:/data02/home/zwh/cassandra/170cassandra/apache-cassandra-3.10/conf/cassandra.yaml
 Error: null; Can't construct a java object for tag:yaml.org,2002:org.apache.cassandra.config.Config; exception=Cannot create property=data_file_directories for JavaBean=org.apache.cassandra.config.Config@16267862; No single argument constructor found for class [Ljava.lang.String;;  in 'reader', line 10, column 1:
    cluster_name: 'Test Cluster'
    ^
Invalid yaml: file:/data02/home/zwh/cassandra/170cassandra/apache-cassandra-3.10/conf/cassandra.yaml
 Error: null; Can't construct a java object for tag:yaml.org,2002:org.apache.cassandra.config.Config; exception=Cannot create property=data_file_directories for JavaBean=org.apache.cassandra.config.Config@16267862; No single argument constructor found for class [Ljava.lang.String;;  in 'reader', line 10, column 1:
    cluster_name: 'Test Cluster'
    ^
ERROR [main] 2017-06-08 16:40:36,340 CassandraDaemon.java:752 - Exception encountered during startup: Invalid yaml: file:/data02/home/zwh/cassandra/170cassandra/apache-cassandra-3.10/conf/cassandra.yaml
 Error: null; Can't construct a java object for tag:yaml.org,2002:org.apache.cassandra.config.Config; exception=Cannot create property=data_file_directories for JavaBean=org.apache.cassandra.config.Config@16267862; No single argument constructor found for class [Ljava.lang.String;;  in 'reader', line 10, column 1:
    cluster_name: 'Test Cluster'
    ^

开始以为配置文件前面不能有空格删掉空格还是报错。折腾了一下发现data_file_directories 配置的时候要按注释的格式

# Directories where Cassandra should store data on disk.  Cassandra
# will spread data evenly across them, subject to the granularity of
# the configured compaction strategy.
# If not set, the default directory is $CASSANDRA_HOME/data/data.
# data_file_directories:
#     - /var/lib/cassandra/data

data_file_directories:
     - /data02/home/zwh/cassandra/170cassandra/data
     - 
原因 配置应该按注释的格式 值要换一行 且前面要加一个 -  

折腾完启动还是报错

com.sun.jna.LastErrorException: [22] h¶<@
    at org.apache.cassandra.utils.CLibrary.fsync(Native Method) ~[apache-cassandra-3.10.jar:3.10]
    at org.apache.cassandra.utils.CLibrary.trySync(CLibrary.java:308) ~[apache-cassandra-3.10.jar:3.10]
    at org.apache.cassandra.utils.SyncUtil.trySync(SyncUtil.java:179) [apache-cassandra-3.10.jar:3.10]
    at org.apache.cassandra.hints.HintsCatalog.fsyncDirectory(HintsCatalog.java:136) [apache-cassandra-3.10.jar:3.10]
    at org.apache.cassandra.hints.HintsWriteExecutor$FsyncWritersTask.run(HintsWriteExecutor.java:189) [apache-cassandra-3.10.jar:3.10]
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [na:1.8.0_131]
    at java.util.concurrent.FutureTask.run(FutureTask.java:266) [na:1.8.0_131]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_131]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_131]
    at org.apache.cassandra.concurrent.NamedThreadFactory.lambda$threadLocalDeallocator$0(NamedThreadFactory.java:79) [apache-cassandra-3.10.jar:3.10]
    at java.lang.Thread.run(Thread.java:748) ~[na:1.8.0_131]

网上资料很少，我也很绝望啊！

v2 adds support for crappy old jna versions