CentOS 7.4 安装 Apache Cassandra 3.7
近期公司提出利用Cassandra 做数据汇总分析，查阅一些文档，总结了一下安装过程
不妥之处，敬请赐教！
环境版本信息：
OS：CentOS Linux release 7.4.1708
cassandra：apache-cassandra-3.7
1.准备工作：
节点规划
计划部署一个4节点的cassandra集群
确认每个节点的hosts文件是否包含其他节点的信息：
[root@gp4 ~]# cat /etc/hosts
127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4
::1 localhost localhost.localdomain localhost6 localhost6.localdomain6
192.168.2.61 gp1
192.168.2.62 gp2
192.168.2.63 gp3
192.168.2.64 gp4
在每个节点上关闭并禁用防火墙：
systemctl status firewalld.service
systemctl stop firewalld.service
systemctl disable firewalld.service
禁用SELinux
sestatus
SELinux status: disabled
vim /etc/selinux/config
安装java运行环境
java -version
wget -c --header "Cookie: oraclelicense=accept-securebackup-cookie" \
http://download.oracle.com/otn-pub/java/jdk/8u131-b11/d54c1d3a095b4ff2b6607d096fa80163/jdk-8u131-linux-x64.rpm
rpm -ivh jdk-8u131-linux-x64.rpm
检查python 是否安装
python --version
Python 2.7.5
对于数据库集群来说，多节点的时间同步很重要：
[root@gp1 ~]# timedatectl status
Local time: Tue 2018-08-21 16:44:42 +08
Universal time: Tue 2018-08-21 08:44:42 UTC
RTC time: Tue 2018-08-21 08:44:43
Time zone: Asia/Shanghai (+08, +0800)
NTP enabled: yes
NTP synchronized: yes
RTC in local TZ: no
DST active: n/a
如果失去有差异，设置为相同时区：
[root@gp1 ~]# timedatectl set-timezone Asia/Shanghai
rm -f /etc/localtime && cp -f /usr/share/zoneinfo/Asia/Shanghai /etc/localtime
安装设置ntp，若没有安装，需手动安装：
[root@gp1 ~]# rpm -qa ntp*
ntp-4.2.6p5-28.el7.centos.x86_64
ntpdate-4.2.6p5-28.el7.centos.x86_64
手动与时间服务器同步时间：
ntpdate 0.us.pool.ntp.org
将时间同步设置为自启动
systemctl enable ntpd
[root@gp1 ~]# ps -ef |grep ntpd
ntp 684 1 0 May31 ? 00:00:04 /usr/sbin/ntpd -u ntp:ntp -g
开启ntpd:
systemctl start ntpd
timedatectl set-ntp yes
ntpq -p
2.为了发挥出数据库的最大性能，需要修改操作系统参数：
cat /etc/sysctl.conf
net.ipv4.tcp_syn_retries = 1
net.ipv4.ip_forward = 1
net.ipv4.tcp_synack_retries = 1
net.ipv4.tcp_keepalive_time = 600
net.ipv4.tcp_keepalive_probes = 3
net.ipv4.tcp_keepalive_intvl =15
net.ipv4.tcp_retries1 = 3
net.ipv4.tcp_retries2 = 5
net.ipv4.tcp_fin_timeout = 10
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_window_scaling = 1
net.ipv4.tcp_max_tw_buckets = 60000
net.ipv4.tcp_max_orphans = 32768
net.ipv4.tcp_max_syn_backlog = 16384
net.ipv4.tcp_mem = 94500000 915000000 927000000
net.ipv4.tcp_wmem = 4096 16384 13107200
net.ipv4.tcp_rmem = 4096 87380 17476000
net.ipv4.ip_local_port_range = 1024 65000
net.ipv4.route.gc_timeout = 100
net.core.somaxconn = 32768
net.core.netdev_max_backlog = 32768
vm.overcommit_memory = 1
vm.swappiness = 1
fs.file-max = 1024000
调整用户资源限制：
cat /etc/security/limits.conf
* soft nofile 1024000
* hard nofile 1024000
* soft nproc 1024000
* hard nproc 1024000
hive - nofile 1024000
hive - nproc 1024000
3.安装步骤
获取安装包：
wget https://archive.apache.org/dist/cassandra/3.7/apache-cassandra-3.7-bin.tar.gz
添加cassandra 组和用户
先检查用户是否存在
id cassandra
id: cassandra: no such user
添加组和用户
groupadd cassandra && useradd -d /home/cassandra -g cassandra cassandra
passwd cassandra
解压安装Cassandra:
tar -zxvf apache-cassandra-3.7-bin.tar.gz -C /usr/local
chown -R cassandra:cassandra /usr/local/apache-cassandra-3.7
切换到cassandra 用户
su - cassandra
修改环境变量：
vi /home/cassandra/.bash_profile
PATH=$PATH:$HOME/.local/bin:$HOME/bin:/usr/local/apache-cassandra-3.7/bin
export CQLSH_NO_BUNDLED=TRUE
export PATH
让环境变量生效
source /home/cassandra/.bash_profile
创建数据和日志目录：
cd /home/cassandra
mkdir ./{commitlog,data,saved_caches}
准备配置文件，主要修改有三个配置文件
cassandra.yaml 里面的参数，都要顶格写，参数前面不能有空格，并且参数名称后面的冒号和参数取值之间必须有空格
cd /usr/local/apache-cassandra-3.7/conf/
vi cassandra.yaml
##需要关注的是以下参数，其他参数可以保持默认值
cluster_name: 'cluster01'
authenticator: PasswordAuthenticator
authorizer: CassandraAuthorizer
roles_validity_in_ms: 600000
roles_update_interval_in_ms: 50000
permissions_validity_in_ms: 600000
permissions_update_interval_in_ms: 50000
credentials_validity_in_ms: 600000
credentials_update_interval_in_ms: 50000
data_file_directories:
- /home/cassandra/data
commitlog_directory: /home/cassandra/commitlog
row_cache_size_in_mb: 1024
saved_caches_directory: /home/cassandra/saved_cache
seed_provider:
# Addresses of hosts that are deemed contact points.
# Cassandra nodes use this list of hosts to find each other and learn
# the topology of the ring. You must change this if you are running
# multiple nodes!
- class_name: org.apache.cassandra.locator.SimpleSeedProvider
parameters:
# seeds is actually a comma-delimited list of addresses.
# Ex: "<ip1>,<ip2>,<ip3>"
- seeds: "192.168.2.61,192.168.2.62,192.168.2.63,192.168.2.64"
disk_optimization_strategy: ssd
memtable_allocation_type: offheap_buffers
listen_address: <host_ip>
broadcast_address: <host_ip>
rpc_address: <host_ip>
broadcast_rpc_address: <host_ip>
endpoint_snitch: GossipingPropertyFileSnitch
batch_size_warn_threshold_in_kb: 20
batch_size_fail_threshold_in_kb: 200
##设置DC 数据中心和 Rack 机架信息
vi cassandra-rackdc.properties
dc1
rack1 <or rack2>
##cassandra基于JIAVA开发，需要为JVM 参数，重点是内存要分配充分。
vi jvm.options
启动Cassandra，
-f 选项将所有引导日志都输出到前台。在首次启动时，可以使用该选项来检查 Cassandra 启动期间的错误。
su - cassandra
cassandra -f
查看集群状态
IP 地址前面的 UN 字母表示节点在正常 (N) 运行 (U)
nodetool status
Datacenter: dc1
===============
Status=Up/Down
|/ State=Normal/Leaving/Joining/Moving
-- Address Load Tokens Owns (effective) Host ID Rack
UN 192.168.2.61 69.33 KiB 256 48.6% d3e764be-43a8-4c03-a562-55a7cf9f8a41 rack1
UN 192.168.2.62 69.34 KiB 256 50.8% fccc7ad7-e6e6-4ee0-a438-3c728b6aaac1 rack2
UN 192.168.2.63 86.77 KiB 256 51.8% a8dd6a51-dcd4-4341-af75-16aee2358c40 rack1
UN 192.168.2.64 105.7 KiB 256 48.9% 769180fd-7d4c-4382-827d-22fdd4349572 rack2
连接登录Cassandra：
[cassandra@gp1 ~]$ cqlsh 192.168.2.61 -u cassandra -p cassandra
Connected to cluster01 at 192.168.2.61:9042.
[cqlsh 5.0.1 | Cassandra 3.7 | CQL spec 3.4.2 | Native protocol v4]
Use HELP for help.
cassandra@cqlsh>
cassandra@cqlsh>
cassandra@cqlsh>
cassandra@cqlsh>
如果 cqlsh连不上库，提示如下：
Python Cassandra driver not installed, or not on PYTHONPATH.
You might try "pip install cassandra-driver".
需要安装驱动
sudo su -
curl https://bootstrap.pypa.io/get-pip.py -o get-pip.py && python get-pip.py && pip install cassandra-driver
su - cassandra
export CQLSH_NO_BUNDLED=TRUE
cqlsh -u cassandra -p cassandra
##安装完成后的准备工作
如果在配置文件中 authorizer 启用用户的授权
authorizer: CassandraAuthorizer
需要增加 system_auth 键空间复制因子，让该键空间在集群中有足够多的副本，用于用户连接授权，只需在一个节点执行：
alter KEYSPACE system_auth WITH replication = { 'class': 'NetworkTopologyStrategy', 'dc1': '3' } AND durable_writes = true;
常用命令：
#查看cluster信息：
cassandra@cqlsh> describe cluster;
Cluster: cluster01
Partitioner: Murmur3Partitioner
#创建 KEYSPACE,复制因子为4
cqlsh> CREATE KEYSPACE test_keyspace WITH replication = {'class': 'SimpleStrategy', 'replication_factor' : 4};
#查看所有keyspaces
cassandra@cqlsh> describe keyspaces;
test_keyspace system_schema system_auth system system_distributed system_traces
#查看keyspaces定义：
desc test_keyspace;
CREATE KEYSPACE test_keyspace WITH replication = {'class': 'SimpleStrategy', 'replication_factor': '4'} AND durable_writes = true;
#创建表
CREATE TABLE test_keyspace.tb01 (
user_id int,
id int,
date timeuuid,
details text,
PRIMARY KEY (user_id, id));
#查示所有表：
use knet ;
describe tables;
或
desc tables;
##插入数据
use test_keyspace;
INSERT INTO tb01 (user_id,id,date,details) values (1,1,now(),'first tb01 test_keyspace 1');
INSERT INTO tb01 (user_id,id,date,details) values (1,2,now(),'second tb01 test_keyspace 1');
INSERT INTO tb01 (user_id,id,date,details) values (2,1,now(),'first tb01 test_keyspace 2');
INSERT INTO tb01 (user_id,id,date,details) values (3,1,now(),'first tb01 test_keyspace 3');
#查询数据：
cqlsh:test_keyspace> select * from tb01 where user_id=1;
用户管理
#初始安装的cassandra默认只有一个用户，实际环境中需要创建应用账户并授予权限：
list users;
name | super
-----------+-------
cassandra | True
(1 rows)
#创建账户,在单个节点执行即可：
CREATE USER testuser_888 WITH PASSWORD 'test12345678' NOSUPERUSER ;
#新建的用户可以连接登入数据库，但是没有操作权限：
testuser_888@cqlsh:test_keyspace> select * from tb01;
Unauthorized: code=2100 [Unauthorized] message="User testuser_888 has no SELECT permission on <table test_keyspace.tb01> or any of its parents
#为用户授权：
GRANT select PERMISSION ON KEYSPACE test_keyspace TO testuser_888;
GRANT modify PERMISSION ON KEYSPACE test_keyspace TO testuser_888;
#查看用户权限：
LIST ALL PERMISSIONS OF testuser_888 NORECURSIVE;
#修改用户密码
alter user testuser_888 with password 'asd!@#456';
drop user cassandra;
list users;
注意：
只有SUPERUSER可以创建用户，创建的用户默认为NOSUPERUSER;
只有SUPERUSER可以删除用户，任何用户不能删除自己。
