CentOS7安装cassandra(单机模式)

新建cassandra用户并修改密码

[k8s-g2@k8s2 ~]$ sudo useradd cassandra
[k8s-g2@k8s2 ~]$ sudo passwd cassandra

配置用户

用户给cassandra用户增加权限

[k8s-g2@k8s2 home]$ sudo vim /etc/sudoers

切换用户

[k8s-g2@k8s2 ~]$ su - cassandra

安装java环境

[cassandra@k8s2 ~]$ sudo yum -y install java-1.8.0-openjdk*   

yum安装的java的默认安装路径在 /usr/lib/jvm,配置环境变量

[cassandra@k8s2 ~]$ vim .bashrc 

export  JAVA_HOME=/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.272.b10-1.el8_2.x86_64
:wq

让配置生效

[cassandra@k8s2 ~]$ source ~/.bashrc

如果想全体用户都可以使用java的话，需要修改/etc/profile文件，添加JAVA_HOME

vi /etc/profile

#set java environment  
export JAVA_HOME=/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.191.b12-0.el7_5.x86_64
export CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar:$JAVA_HOME/jre/lib/rt.jar
export PATH=$PATH:$JAVA_HOME/bin
:wq

. /etc/profile    //使配置生效

验证java是否安装成功

• 验证JAVA_HOME

[cassandra@k8s2 ~]$ echo $JAVA_HOME

• 验证java安装是否成功

[cassandra@k8s2 ~]$ java -version
openjdk version "1.8.0_272"
OpenJDK Runtime Environment (build 1.8.0_272-b10)
OpenJDK 64-Bit Server VM (build 25.272-b10, mixed mode)

• 验证jdk是否安装成功

[cassandra@k8s2 ~]$ javac
用法: javac <options> <source files>

下载安装cassandra

下载cassandra忽略证书检查

wget https://mirrors.cnnic.cn/apache/cassandra/3.11.9/apache-cassandra-3.11.9-bin.tar.gz --no-check-certificate

解压缩cassandra

[cassandra@k8s2 ~]$ tar -zxvf apache-cassandra-3.11.9-bin.tar.gz 

到指定的位置创建文件夹，这里使用的是/

[cassandra@k8s2 /]$ sudo mkdir cassandra
[cassandra@k8s2 /]$ sudo mv apache-cassandra-3.11.9/* /cassandra.

配置cassandra.yaml及环境变量

[cassandra@k8s2 cassandra]$ cd conf/

修改cassandra.yaml文件。验证以下配置。 默认情况下，这些值将设置为指定的目录。

• data_file_directories “/var/ lib/cassandra/data”
• commitlog_directory “/var/lib/cassandra/commitlog”
• saved_caches_directory “/var/lib/cassandra/saved_caches”

确保这些目录存在并且可以写入，如下所示。

[root@linux cassandra]# mkdir /var/lib/cassandra
[root@linux cassandra]# mkdir /var/log/cassandra
[root@linux /]# chmod 777 /var/lib/cassandra
[root@linux /]# chmod 777 /var/log/cassandra

本次测试建立另一个目录保存

[cassandra@k8s2 /]$ sudo mkdir data
[cassandra@k8s2 /]$ sudo mkdir data/{data,commitlog,saved_caches} -p  
[cassandra@k8s2 /]$ sudo chmod 777 -R data/

因此目录对应关系如下：

• data_file_directories “/data/data”
• commitlog_directory “/data/commitlog”
• saved_caches_directory “/data/saved_caches”
  按照此对应修改cassandra.yaml文件

配置环境变量

[cassandra@k8s2 ~]$ vim .bashrc 

export CASSANDRA_HOME=/cassandra
export PATH=$PATH:$CASSANDRA_HOME/bin

 [cassandra@k8s2 ~]$ source ~/.bashrc
 [cassandra@k8s2 ~]$ echo $CASSANDRA_HOME
/cassandra

启动cassandra

[cassandra@k8s2 bin]$ ./cassandra -f

本次启动报错

OpenJDK 64-Bit Server VM warning: Cannot open file /cassandra/logs/gc.log due to No such file or directory

于是手工建立一个logs这个目录

[cassandra@k8s2 cassandra]$ sudo mkdir logs
[cassandra@k8s2 cassandra]$ sudo chown cassandra:cassandra logs

再次启动，报错

ERROR [main] 2020-11-25 14:47:55,403 CassandraDaemon.java:803 - Local host name unknown: java.net.UnknownHostException: bogon: bogon: 未知的名称或服务

修改hostname,host,网卡中指定hostname

再次启动，报错

ERROR [main] 2020-11-25 15:21:46,387 CassandraDaemon.java:803 - Has no permission to create directory /cassandra/data/hints

手工建立相关目录,再次启动,成功
正常启动

[cassandra@k8s2 bin]$ ./cassandra -f
[cassandra@k8s2 network-scripts]$ netstat -tpln
(Not all processes could be identified, non-owned process info
 will not be shown, you would have to be root to see it all.)
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name    
tcp        0      0 127.0.0.1:46253         0.0.0.0:*               LISTEN      12781/java          
tcp        0      0 0.0.0.0:111             0.0.0.0:*               LISTEN      -                   
tcp        0      0 192.168.56.102:9042     0.0.0.0:*               LISTEN      12781/java          
tcp        0      0 192.168.122.1:53        0.0.0.0:*               LISTEN      -                   
tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      -                   
tcp        0      0 127.0.0.1:631           0.0.0.0:*               LISTEN      -                   
tcp        0      0 192.168.56.102:7000     0.0.0.0:*               LISTEN      12781/java          
tcp        0      0 127.0.0.1:6010          0.0.0.0:*               LISTEN      -                   
tcp        0      0 127.0.0.1:6011          0.0.0.0:*               LISTEN      -                   
tcp        0      0 127.0.0.1:7199          0.0.0.0:*               LISTEN      12781/java          
tcp        0      0 0.0.0.0:5355            0.0.0.0:*               LISTEN      -                   
tcp6       0      0 :::111                  :::*                    LISTEN      -                   
tcp6       0      0 :::22                   :::*                    LISTEN      -                   
tcp6       0      0 ::1:631                 :::*                    LISTEN      -                   
tcp6       0      0 ::1:6010                :::*                    LISTEN      -                   
tcp6       0      0 ::1:6011                :::*                    LISTEN      -                   
tcp6       0      0 :::5355                 :::*                    LISTEN      -   

在命令行窗口执行命令bin/cassandra -f，按“Control-C” 停止Cassandra.
如果是通过命令行bin/cassandra后台启动Cassandra，那么必须调用kill pid or pkill -f CassandraDaemon 来停止Cassandra, 其中pid是Cassandra的进程id, 此pid能够通过执行pgrep -f CassandraDaemon得到。