Introduction
What is Cassandra?
The Apache Cassandra database is the right choice when you need scalability(伸缩) and high availability without compromising performance. Linear scalability and proven fault-tolerance(容错系统)on commodity hardware or cloud infrastructure make it the perfect platform for mission-critical data.Cassandra's support for replicating across multiple datacenters is best-in-class, providing lower latency for your users and the peace of mind of knowing that you can survive（生存） regional outages.
Prerequisites
CentOS release 6.5 (Final)
系统参数配置
[root@sht-sgmhadoopdn-02 ~]# vim /etc/security/limits.conf
tnuser soft memlock unlimited
tnuser hard memlock unlimited
[root@sht-sgmhadoopdn-02 ~]# sysctl -w vm.max_map_count=131072
[root@sht-sgmhadoopdn-02 ~]# echo "vm.max_map_count=131072" >> /etc/sysctl.conf
[root@sht-sgmhadoopdn-02 ~]#vim /etc/security/limits.d/90-nproc.conf
* soft nproc 1024
改为：
* soft nproc 10240
[root@sht-sgmhadoopdn-02 ~]# swapoff -a
软件准备:cassandra,jdk,python
[root@sht-sgmhadoopdn-02 softwore]# ll
total 218276
-rw-r--r-- 1 dhchen Corp_User 25288340 Aug 14 14:44 apache-cassandra-2.1.18-bin.tar.gz
-rw-r--r-- 1 dhchen Corp_User 181442359 Aug 14 14:43 jdk-8u111-linux-x64.tar.gz
-rw-r--r-- 1 dhchen Corp_User 16768806 Aug 14 14:44 Python-2.7.10.tgz
创建用户组和用户
[root@sht-sgmhadoopdn-02 softwore]# groupadd appuser
[root@sht-sgmhadoopdn-02 softwore]#useradd -g appuser -G root -d /usr/local/cassandra tnuser
安装JAVA
[root@sht-sgmhadoopdn-02 softwore]# tar xf jdk-8u111-linux-x64.tar.gz -C /usr/local/
[root@sht-sgmhadoopdn-02 local]# ln -s /usr/local/jdk1.8.0_111 /usr/local/java
[root@sht-sgmhadoopdn-02 local]# chown -R tnuser:appuser /usr/local/java
[root@sht-sgmhadoopdn-02 local]# /usr/local/java/bin/java -version
java version "1.8.0_111"
Java(TM) SE Runtime Environment (build 1.8.0_111-b14)
Java HotSpot(TM) 64-Bit Server VM (build 25.111-b14, mixed mode)
安装python
[root@sht-sgmhadoopdn-02 local]# tar xf Python-2.7.10.tgz -C /usr/local
[root@sht-sgmhadoopdn-02 local]# cd Python-2.7.10
[root@sht-sgmhadoopdn-02 Python-2.7.10]# ./configure --prefix=/usr/local/python
[root@sht-sgmhadoopdn-02 Python-2.7.10]#make && make install
[root@sht-sgmhadoopdn-02 local]# chown -R tnuser:appuser /usr/local/python
[root@sht-sgmhadoopdn-02 local]# /usr/local/python/bin/python --version
Python 2.7.10
安装cassandra
[root@sht-sgmhadoopdn-02 local]# tar xf /opt/softwore/apache-cassandra-2.1.18-bin.tar.gz -C /usr/local/
[root@sht-sgmhadoopdn-02 local]# ln -s /usr/local/apache-cassandra-2.1.18 /usr/local/cassandra
[root@sht-sgmhadoopdn-02 local]# chown -R tnuser:appuser /usr/local/apache-cassandra-2.1.18
[root@sht-sgmhadoopdn-02 local]# chown -R tnuser:appuser /usr/local/cassandra
#加入自启动（可以不做这一步）
[root@sht-sgmhadoopdn-02 local]# vim /etc/rc.local
su - tnuser -c "cd /usr/local/cassandra/bin/ && nohup ./cassandra "
设置环境变量
[root@sht-sgmhadoopdn-02 local]# su - tnuser
[tnuser@sht-sgmhadoopdn-02 ~]$ cat ~/.bash_profile
export CASSANDRA_HOME=/usr/local/cassandra
export JAVA_HOME=/usr/local/java
export PYTHON_HOME=/usr/local/python
PATH=$PYTHON_HOME/bin:$JAVA_HOME/bin:$CASSANDRA_HOME/bin:$CASSANDRA_HOME/tools/bin:$PATH:$HOME/bin:/usr/local/bin
export PATH
set umask to 022
umask 022
PS1=`uname -n`":"'$USER'":"'$PWD'":>"; export PS1
[tnuser@sht-sgmhadoopdn-02 ~]$ source .bash_profile
[tnuser@sht-sgmhadoopdn-02 ~]$ python -V
Python 2.7.10
[tnuser@sht-sgmhadoopdn-02 ~]$ java -version
java version "1.8.0_111"
Java(TM) SE Runtime Environment (build 1.8.0_111-b14)
Java HotSpot(TM) 64-Bit Server VM (build 25.111-b14, mixed mode)
创建相关目录
[tnuser@sht-sgmhadoopdn-02 cassandra]$ mkdir -p /usr/local/cassandra/{data,commitlog,log,saved_caches}
设置配置文件:cassadnra.yaml
[tnuser@sht-sgmhadoopdn-02 conf]$ vim /usr/local/cassandra/conf/cassandra.yaml
cluster_name: 'mycluster'
data_file_directories:
- /usr/local/cassandra/data
commitlog_directory: /usr/local/cassandra/commitlog
saved_caches_directory: /usr/local/cassandra/saved_caches
- seeds: "172.16.101.59"
# Ex: "<ip1>,<ip2>,<ip3>"
listen_address: 172.16.101.59
native_transport_port: 9042
start_rpc: true
rpc_address: 0.0.0.0
rpc_port: 9160
broadcast_rpc_address: 172.16.101.59
设置配置文件: logback.xml
[tnuser@sht-sgmhadoopdn-02 conf]$ vim /usr/local/cassandra/conf/logback.xml
<level>INFO</level>
</filter>
<file>/usr/local/cassandra/log/system.log</file>
启动cassandra
[tnuser@sht-sgmhadoopdn-02 cassandra]$cassandra
[tnuser@sht-sgmhadoopdn-02 cassandra]$ netstat -nltup |grep -e 9042 -e 9160
tcp 0 0 0.0.0.0:9042 0.0.0.0:* LISTEN 24286/java
tcp 0 0 0.0.0.0:9160 0.0.0.0:* LISTEN 24286/java
[tnuser@sht-sgmhadoopdn-02 cassandra]$ lsof -Pnl|grep -e 9042 -e 9160
java 24286 503 72u IPv4 35165833 0t0 TCP *:9042 (LISTEN)
java 24286 503 73u IPv4 35165834 0t0 TCP *:9160 (LISTEN)
[tnuser@sht-sgmhadoopdn-02 ~]$ ps -ef |grep cassandra
tnuser 24286 1 2 18:00 pts/4 00:00:29 /usr/local/java/bin/java -ea -javaagent:/usr/local/cassandra/lib/jamm-0.3.0.jar -XX:+CMSClassUnloadingEnabled -XX:+UseThreadPriorities -XX:ThreadPriorityPolicy=42 -Xms1463M -Xmx1463M -Xmn200M -XX:+HeapDumpOnOutOfMemoryError -Xss256k -XX:StringTableSize=1000003 -XX:+UseParNewGC -XX:+UseConcMarkSweepGC -XX:+CMSParallelRemarkEnabled -XX:SurvivorRatio=8 -XX:MaxTenuringThreshold=1 -XX:CMSInitiatingOccupancyFraction=75 -XX:+UseCMSInitiatingOccupancyOnly -XX:+UseTLAB -XX:CompileCommandFile=/usr/local/cassandra/conf/hotspot_compiler -XX:CMSWaitDuration=10000 -XX:+CMSParallelInitialMarkEnabled -XX:+CMSEdenChunksRecordAlways -XX:CMSWaitDuration=10000 -XX:+UseCondCardMark -Djava.net.preferIPv4Stack=true -Dcassandra.jmx.local.port=7199 -XX:+DisableExplicitGC -Dlogback.configurationFile=logback.xml -Dcassandra.logdir=/usr/local/cassandra/logs -Dcassandra.storagedir=/usr/local/cassandra/data -cp /usr/local/cassandra/conf:/usr/local/cassandra/build/classes/main:/usr/local/cassandra/build/classes/thrift:/usr/local/cassandra/lib/airline-0.6.jar:/usr/local/cassandra/lib/antlr-runtime-3.5.2.jar:/usr/local/cassandra/lib/apache-cassandra-2.1.18.jar:/usr/local/cassandra/lib/apache-cassandra-clientutil-2.1.18.jar:/usr/local/cassandra/lib/apache-cassandra-thrift-2.1.18.jar:/usr/local/cassandra/lib/commons-cli-1.1.jar:/usr/local/cassandra/lib/commons-codec-1.2.jar:/usr/local/cassandra/lib/commons-lang3-3.1.jar:/usr/local/cassandra/lib/commons-math3-3.2.jar:/usr/local/cassandra/lib/compress-lzf-0.8.4.jar:/usr/local/cassandra/lib/concurrentlinkedhashmap-lru-1.4.jar:/usr/local/cassandra/lib/disruptor-3.0.1.jar:/usr/local/cassandra/lib/guava-16.0.jar:/usr/local/cassandra/lib/high-scale-lib-1.0.6.jar:/usr/local/cassandra/lib/jackson-core-asl-1.9.2.jar:/usr/local/cassandra/lib/jackson-mapper-asl-1.9.2.jar:/usr/local/cassandra/lib/jamm-0.3.0.jar:/usr/local/cassandra/lib/javax.inject.jar:/usr/local/cassandra/lib/jbcrypt-0.3m.jar:/usr/local/cassandra/lib/jline-1.0.jar:/usr/local/cassandra/lib/jna-4.0.0.jar:/usr/local/cassandra/lib/json-simple-1.1.jar:/usr/local/cassandra/lib/libthrift-0.9.2.jar:/usr/local/cassandra/lib/logback-classic-1.1.2.jar:/usr/local/cassandra/lib/logback-core-1.1.2.jar:/usr/local/cassandra/lib/lz4-1.2.0.jar:/usr/local/cassandra/lib/metrics-core-2.2.0.jar:/usr/local/cassandra/lib/netty-all-4.0.44.Final.jar:/usr/local/cassandra/lib/reporter-config-2.1.0.jar:/usr/local/cassandra/lib/slf4j-api-1.7.2.jar:/usr/local/cassandra/lib/snakeyaml-1.11.jar:/usr/local/cassandra/lib/snappy-java-1.0.5.2.jar:/usr/local/cassandra/lib/ST4-4.0.8.jar:/usr/local/cassandra/lib/stream-2.5.2.jar:/usr/local/cassandra/lib/super-csv-2.1.0.jar:/usr/local/cassandra/lib/thrift-server-0.3.7.jar org.apache.cassandra.service.CassandraDaemon
登录方式
[tnuser@sht-sgmhadoopdn-02 cassandra]$ cqlsh
cqlsh>
停止cassandra服务
#先找到cassandra对应的进程号，然后kill
pgrep命令以名称为依据从运行进程队列中查找进程，并显示查找到的进程id。
-u Only match processes whose real user ID is listed. Either the numerical or symbolical value may be used.
-f The pattern is normally only matched against the process name. When -f is set, the full command line is used.
[tnuser@sht-sgmhadoopdn-02 ~]$ pgrep -l -u tnuser
24286 java
25586 bash
[tnuser@sht-sgmhadoopdn-02 ~]$ pgrep -u tnuser -f cassandra
24286
[tnuser@sht-sgmhadoopdn-02 ~]$ pgrep -u tnuser -f cassandra|xargs kill -9
Error
(1)在启动cassand时候报错：
[tnuser@sht-sgmhadoopdn-02 cassandra]$ cassandra
.......
ERROR:java.lang.RuntimeException: Unable to gossip with any seeds
.......
Solution:
修改配置文件
[tnuser@sht-sgmhadoopdn-02 cassandra]$ vim /usr/local/cassandra/conf/cassandra.yaml
- seeds: "127.0.0.1" 改为
- seeds: "172.16.101.59"
(2)在使用cqlsh登录的时候报错
Darren2:tnuser:/usr/local/cassandra:>cqlsh
Traceback (most recent call last):
File "/usr/local/cassandra/bin/cqlsh.py", line 168, in <module>
from cqlshlib import cql3handling, cqlhandling, pylexotron, sslhandling, cqlshhandling
File "/usr/local/cassandra/bin/../pylib/cqlshlib/sslhandling.py", line 20, in <module>
import ssl
File "/usr/local/python/lib/python2.7/ssl.py", line 97, in <module>
import _ssl # if we can't import it, let the error propagate
ImportError: No module named _ssl
原因：python中ssl模块无法正常调用
Darren2:tnuser:/usr/local:>python
Python 2.7.10 (default, Oct 18 2017, 21:17:45)
[GCC 4.4.7 20120313 (Red Hat 4.4.7-4)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import ssl
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/local/python/lib/python2.7/ssl.py", line 97, in <module>
import _ssl # if we can't import it, let the error propagate
[root@Darren2 local]# yum list installed | grep ssl
openssl.x86_64 1.0.1e-15.el6 @anaconda-CentOS-201311272149.x86_64/6.5
openssl098e.x86_64 0.9.8e-17.el6.centos.2
解决方法：
[root@Darren2 local]#yum install openssl-devel -y
重新安装python;
Darren2:tnuser:/usr/local/cassandra:>python
>>> import ssl;
>>> import _ssl
>>> quit();
本文转自 Darren_Chen 51CTO博客，原文链接：http://blog.51cto.com/darrenmemos/1980830，如需转载请自行联系原作者