Postgres-XL集群安装部署

一、集群的规划 

注:角色都可以根据自己的需求来划分，可灵活的调整

二、创建用户并装备环境，以下操作无特殊说明，每个节点都需要进行操作
1、创建postgres用户,并且创建ssh免密登陆的目录，授予权限

useradd postgres 
 passwd postgres
 su - postgres
 mkdir ~/.ssh
 chmod 700 ~/.ssh

2、关闭防火墙和selinux 

systemctl stop firewalld
 systemctl disable firewalld   #重启不会启动
 systemctl status firewalld    #查看一下状态，确定一下
 关闭selinux,编辑/etc/selinux/config文件
 将SELINUX的值设置为disabled

3、进行域名解析，配置/etc/hosts,在末尾添加如下内容 

192.168.1.1 gtm
192.168.1.5 datanode1
192.168.1.6 datanode2
192.168.1.7 backupnode1
192.168.1.8 backupnode2

4、配置gtm到其他节点免密ssh登陆，在gtm节点操作 

su – postgres
 ssh-keygen -t rsa    #这里一定要一直按回车，不要输入任何字符
 cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys 
 chmod 600 ~/.ssh/authorized_keys 
 scp ~/.ssh/authorized_keys postgres@datanode1:~/.ssh/authorized_keys
 scp ~/.ssh/authorized_keys postgres@datanode2:~/.ssh/authorized_keys
 scp ~/.ssh/authorized_keys postgres@backupnode1:~/.ssh/authorized_keys
 scp ~/.ssh/authorized_keys postgres@backupnode2:~/.ssh/authorized_keys

tar -zxvf postgres-xl-9.5r1.6.tar.gz
cd postgres-xl
./configure --prefix=/home/postgres/pgxl/
make
make install
cd contrib/
make
make install

4、配置环境变量，在每个节点操作，需切换到postgres用户 

su – postgres
# vi ~/.bashrc
export PGHOME=/usr/local/pgsql
export LD_LIBRARY_PATH=$PGHOME/lib:$LD_LIBRARY_PATH
export PATH=$PGHOME/bin:$PATH
# source ~/.bashrc

注：可以用echo $PGHOME查看变量是否生效
5、每个节点目录权限设置，切换为root用户 su root

# chown -R postgres:postgres /usr/local/pgsql

6、配置集群配置文件，仅在gtm上配置，先生成一份模板，在修改其中内容，然后同步到其他设备， 

gxc_ctl              ---忽略错误提示
PGXC prepare         ---该命令会生成一份模板配置文件
PGXC ^C

编辑/home/postgres/pgxc_ctl/pgxc_ctl.conf 

#---- GTM Master -----------------------------------------------

#---- Overall ----
gtmName=gtm
gtmMasterServer=gtm
gtmMasterPort=6666
gtmMasterDir=$HOME/pgxc/nodes/gtm

#---- Configuration ---
gtmExtraConfig=none                     # Will be added gtm.conf for both Master and Slave (done at initilization only)
gtmMasterSpecificExtraConfig=none       # Will be added to Master's gtm.conf (done at initialization only)

#---- GTM Slave -----------------------------------------------

# Because GTM is a key component to maintain database consistency, you may want to configure GTM slave
# for backup.

#---- Overall ------
gtmSlave=y                                      # Specify y if you configure GTM Slave.   Otherwise, GTM slave will not be configured and
                                                        # all the following variables will be reset.
gtmSlaveName=gtm_slaver
gtmSlaveServer=backupnode1              # value none means GTM slave is not available.  Give none if you don't configure GTM Slave.
gtmSlavePort=20001                      # Not used if you don't configure GTM slave.
gtmSlaveDir=$HOME/pgxc/nodes/gtm        # Not used if you don't configure GTM slave.
# Please note that when you have GTM failover, then there will be no slave available until you configure the slave
# again. (pgxc_add_gtm_slave function will handle it)

#---- Configuration ----
gtmSlaveSpecificExtraConfig=none # Will be added to Slave's gtm.conf (done at initialization only)

注：我只贴出部分配置，每个模块都一样，根据自己的规划图来配置

四、初始化集群并且启动集群，在gtm上初始化，操作会自动初始化（配置）各个节点。

pgxc_ctl  init all      #会初始化其他节点
pgxc_ctl  monitor all   #查看节点是否运行

五、测试集群
可以在任意节点上输入以下命令，查看除gtm以外的所有节点的配置情况： 

select * from pgxc_node;

简单的测试，在datanode1节点上创建一个数据库test，并创建一个表test，插入数据： 

psql -p 20004 -U postgres 
CREATE DATABASE test;
\c test
CREATE TABLE test(id int);
INSERT INTO test VALUES(1);
SELECT * FROM test;
\q

在datanode2节点上查看刚刚在datanode1节点的更改： 

psql -p 20004 -U postgres  
\c test
SELECT * FROM test;
\q

测试是有数据，至此我们的pg_xl集群搭建完毕！