Postgres-XL集群搭建

Postgres-XL 是一个完全满足ACID的、开源的、可方便进行水平扩展的、多租户安全的。支持share-nothing;支持海量数据并行处理-MPP(Massively Parallel Processing)。是不是跟 greenplum很相似。

主机分配

3台主机，安装centos6.2。当然可以准备多台服务器；这个视场景而定合理安排（gtm为一台独立的主机；例外每台机器最好同时配置一个Coordinator和一个Datanode，这样既不用担心二者的负载均衡，而且可以降低网络流量）；

192.168.1.201 (gtm)

192.168.1.202 (coordinator,datanode)

192.168.1.203 (coordinator,datanode)

Postgres-XL下载安装

下载地址 -- http://www.postgres-xl.org/download/

下载包：--postgres-xl-v9.2-src.tar.gz

在每一个节点上安装依赖包；

yum install -y flex bison readline-devel zlib-devel openjade docbook-style-dsssl gcc

安装Postgres-XL

在每个节点执行

# tar -zxvf postgres-xl-v9.2-src.tar.gz

# cd postgres-xl1

# ./configure --prefix=/usr/local/pgxl-9.2 --安装目录；可以不带。

# make

# make install

在gtm主机；即192.168.1.201执行安装工具pgxc_ctl

# cd contrib/pgxc_ctl

# make

# make install

创建用户

# useradd postgres

# passwd postgres

配置环境变量

export PGUSER=postgres

export PGHOME=/usr/local/pgxl-9.2

export LD_LIBRARY_PATH=$PGHOME/lib:$LD_LIBRARY_PATH

export PATH=$HOME/bin:$PGHOME/bin:$PATH

在postgres家目录下的.bashrc文件添加上面内容；并source .bashrc使之生效!

配置ssh免密码登录for pgxc_ctl;

$ ssh-keygen -t rsa

$ cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys

$ chmod 600 ~/.ssh/authorized_keys

$ scp ~/.ssh/authorized_keys postgres@192.168.1.202:~/.ssh/

$ scp ~/.ssh/authorized_keys postgres@192.168.1.203:~/.ssh/

若其他服务器没有.ssh目录；可手动创建下 mkdir .ssh;chmod 700 .ssh

配置集群并使用pgxc_ctl初始化集群；

在gtm节点服务器操作；新建192.168.1.201服务器的/home/postgres/pgxc_ctl/pgxc_ctl.conf文件；添加如下内容

#user and path 
pgxcOwner=postgres
pgxcUser=$pgxcOwner
pgxcInstallDir=/usr/local/pgxl-9.2

#gtm and gtmproxy
gtmMasterDir=$HOME/pgxc/nodes/gtm
gtmMasterPort=6666
gtmMasterServer=192.168.1.201
gtmSlave=n

#gtm proxy
gtmProxy=n

#coordinator
coordMasterDir=$HOME/pgxc/nodes/coord
coordNames=(coord1 coord2)
coordPorts=(5432 5432)
poolerPorts=(6667 6668)
coordPgHbaEntries=(192.168.1.0/32)
coordMasterServers=(192.168.1.202 192.168.1.203)
coordMasterDirs=($coordMasterDir/coord1 $coordMasterDir/coord2)
coordMaxWALsernder=0
coordMaxWALSenders=($coordMaxWALsernder $coordMaxWALsernder)
coordSlave=n
coordSpecificExtraConfig=(none none none)
coordSpecificExtraPgHba=(none none none)

#datanode
datanodeNames=(datanode1 datanode2)
datanodePorts=(15432 15432)
datanodePoolerPorts=(6669 6670)
datanodePgHbaEntries=(192.168.1.0/32)
datanodeMasterServers=(192.168.1.202 192.168.1.203)
datanodeMasterDir=$HOME/pgxc/nodes/datanode
datanodeMasterDirs=($datanodeMasterDir/datanode1 $datanodeMasterDir/datanode2)
datanodeMaxWalSender=0
datanodeMaxWALSenders=($datanodeMaxWalSender $datanodeMaxWalSender)
datanodeSlave=n
primaryDatanode=datanode1

初始化集群

pgxc_ctl -c /home/postgres/pgxc_ctl/pgxc_ctl.conf init all

启动/关闭集群

pgxc_ctl -c /home/postgres/pgxc_ctl/pgxc_ctl.conf start all

pgxc_ctl -c /home/postgres/pgxc_ctl/pgxc_ctl.conf stop all

配置集群信息

在coordinator，datanode节点操作

在服务器192.168.1.202，192.168.1.203操作进入psql目录下 psql -p 5432 -d postgres ,psql -p 15432 -d postgres其他node做对应的操作;本地node只坐修改即可；其他都要create node。

select * from pgxc_node;

create node coord1 with (type=coordinator,host='192.168.1.202', port=5432);

create node coord2 with (type=coordinator,host='192.168.1.203', port=5432);

alter node coord1 with (type=coordinator,host='192.168.1.202', port=5432);

alter node coord2 with (type=coordinator,host='192.168.1.203', port=5432);

create node datanode1 with (type=datanode, host='192.168.1.202',port=15432,primary=true);

create node datanode2 with (type=datanode, host='192.168.1.203',port=15432);

alter node datanode1 with (type=datanode, host='192.168.1.202',port=15432,primary=true);

alter node datanode2 with (type=datanode, host='192.168.1.203',port=15432);

select pgxc_pool_reload();

测试环境OK？

以上步骤做好了；开始测试操作

[postgres@localhost datanode1]$ psql -p 5432 postgres
psql (PGXL 9.2.0, based on PG 9.2.4 (Postgres-XL 9.2.0))
Type "help" for help.

postgres=# create role lottu nosuperuser login encrypted password 'li0924';  
CREATE ROLE
postgres=# create tablespace tbs_lottu owner postgres location '/home/postgres/data/lottu'; 
ERROR:  directory "/home/postgres/data/lottu" does not exist
postgres=# create tablespace tbs_lottu owner postgres location '/home/postgres/data/lottu'; 
CREATE TABLESPACE
postgres=# create database lottu owner lottu template template0 encoding 'UTF8' tablespace tbs_lottu; 
CREATE DATABASE

postgres=# \c lottu lottu

lottu=> create table lottu01 (id int primary key, name varchar(10));
NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index "lottu01_pkey" for table "lottu01"
CREATE TABLE

lottu=> insert into lottu01 select generate_series(1,1000),'lottu'||generate_series(1,1000);
INSERT 0 1000

[postgres@localhost datanode1]$ psql -p 5432 lottu lottu
psql (PGXL 9.2.0, based on PG 9.2.4 (Postgres-XL 9.2.0))
Type "help" for help.
lottu=> select count(*) from lottu01;
 count 
-------
  1000
(1 row)
lottu=> \q
[postgres@localhost datanode1]$ psql -p 15432 lottu lottu
psql (PGXL 9.2.0, based on PG 9.2.4 (Postgres-XL 9.2.0))
Type "help" for help.
lottu=> select count(*) from lottu01;
 count 
-------
   492
(1 row)
[postgres@localhost ~]$ psql -p 15432 lottu lottu
psql (PGXL 9.2.0, based on PG 9.2.4 (Postgres-XL 9.2.0))
Type "help" for help.

lottu=> select count(*) from lottu01;
 count 
-------
   508
(1 row)

【FAQ】

1. 在配置集群信息出现

“WARNING: can not connect to GTM: No route to host

WARNING: Xid is invalid.

ERROR: GTM error, could not obtain snapshot XID = 0”

分析原因：看提示“No route to host”跟网络路由有关；也可以能跟防火墙有关

解决方案：配置防火墙或者关闭防火墙

2. 在创建role时出现“ERROR: Failed to get pooled connections”

分析原因：

1.首先我查看了pool进程是否存在；

2.核对检查下pgxc_pool的配置是否OK；

3.执行psql -h 192.168.1.203 -p 5432 发现超时；这就跟pg_hba.conf文件有关。

解决方案：

添加host all all 192.168.1.0/32 trust

其中的32跟主机设置的netmask有关

参考文献

--https://ruihaijiang.wordpress.com/2015/09/17/postgres-xl-installation-example-on-linux/

来源：https://www.cnblogs.com/lottu/p/5646486.html

标签

postgres-xl

host