[TOC]
概述
新安装的greenplum集群只有primary节点，没有mirror。高可用性没得到保证。所以就需要为集群添加mirror节点
注意：数据量过大时添加mirror，会有较大的磁盘压力，因为后台会一直同步数据，这一点线上系统需要注意
添加前情况
初始化的时候只有primary
20190326:00:48:33:005423 gpinitsystem:gw_mdw1:gpadmin-[INFO]:-Greenplum Primary Segment Configuration
20190326:00:48:33:005423 gpinitsystem:gw_mdw1:gpadmin-[INFO]:----------------------------------------
20190326:00:48:33:005423 gpinitsystem:gw_mdw1:gpadmin-[INFO]:-gw_sdw1 /data/primary/gpseg0 40000 2 0
20190326:00:48:33:005423 gpinitsystem:gw_mdw1:gpadmin-[INFO]:-gw_sdw1 /data/primary/gpseg1 40001 3 1
20190326:00:48:33:005423 gpinitsystem:gw_mdw1:gpadmin-[INFO]:-gw_sdw1 /data/primary/gpseg2 40002 4 2
20190326:00:48:33:005423 gpinitsystem:gw_mdw1:gpadmin-[INFO]:-gw_sdw1 /data/primary/gpseg3 40003 5 3
20190326:00:48:33:005423 gpinitsystem:gw_mdw1:gpadmin-[INFO]:-gw_sdw2 /data/primary/gpseg4 40000 6 4
20190326:00:48:33:005423 gpinitsystem:gw_mdw1:gpadmin-[INFO]:-gw_sdw2 /data/primary/gpseg5 40001 7 5
20190326:00:48:33:005423 gpinitsystem:gw_mdw1:gpadmin-[INFO]:-gw_sdw2 /data/primary/gpseg6 40002 8 6
20190326:00:48:33:005423 gpinitsystem:gw_mdw1:gpadmin-[INFO]:-gw_sdw2 /data/primary/gpseg7 40003 9 7
Continue with Greenplum creation Yy/Nn>查看系统配置表，发现只有primary节点
postgres=# SELECT * from gp_segment_configuration ;
dbid | content | role | preferred_role | mode | status | port | hostname | address | replication_port | san_mounts
------+---------+------+----------------+------+--------+-------+----------+---------+------------------+------------
1 | -1 | p | p | s | u | 5432 | gw_mdw1 | gw_mdw1 | |
2 | 0 | p | p | s | u | 40000 | gw_sdw1 | gw_sdw1 | |
6 | 4 | p | p | s | u | 40000 | gw_sdw2 | gw_sdw2 | |
3 | 1 | p | p | s | u | 40001 | gw_sdw1 | gw_sdw1 | |
7 | 5 | p | p | s | u | 40001 | gw_sdw2 | gw_sdw2 | |
4 | 2 | p | p | s | u | 40002 | gw_sdw1 | gw_sdw1 | |
8 | 6 | p | p | s | u | 40002 | gw_sdw2 | gw_sdw2 | |
5 | 3 | p | p | s | u | 40003 | gw_sdw1 | gw_sdw1 | |
9 | 7 | p | p | s | u | 40003 | gw_sdw2 | gw_sdw2 | |
(9 rows)
添加步骤
在所有需要添加mirror的主机，创建存放mirror的数据目录
可以使用gpssh命令
gpssh -f seg_hosts -e 'mkdir -p /data/mirror'生成addmirror文件
执行gpaddmirrors 命令，键入存放mirror节点的日志，生成配置文件
[gpadmin@gw_mdw1 ~]$ gpaddmirrors -o ./addmirror
20190326:00:56:21:030831 gpaddmirrors:gw_mdw1:gpadmin-[INFO]:-Starting gpaddmirrors with args: -o ./addmirror
20190326:00:56:21:030831 gpaddmirrors:gw_mdw1:gpadmin-[INFO]:-local Greenplum Version: 'postgres (Greenplum Database) 4.3.1.0 build 6'
20190326:00:56:21:030831 gpaddmirrors:gw_mdw1:gpadmin-[INFO]:-master Greenplum Version: 'PostgreSQL 8.2.15 (Greenplum Database 4.3.1.0 build 6) on x86_64-unknown-linux-gnu, compiled by GCC gcc (GCC) 4.4.2 compiled on Jun 11 2014 17:23:40'
20190326:00:56:21:030831 gpaddmirrors:gw_mdw1:gpadmin-[INFO]:-Obtaining Segment details from master...
Enter mirror segment data directory location 1 of 4 >
/data/mirror
Enter mirror segment data directory location 2 of 4 >
/data/mirror
Enter mirror segment data directory location 3 of 4 >
/data/mirror
Enter mirror segment data directory location 4 of 4 >
/data/mirror
20190326:00:57:15:030831 gpaddmirrors:gw_mdw1:gpadmin-[INFO]:-Configuration file output to ./addmirror successfully.查看文件内容如下
[gpadmin@gw_mdw1 ~]$ cat addmirror
filespaceOrder=
mirror0=0:gw_sdw2:41000:42000:43000:/data/mirror/gpseg0
mirror1=1:gw_sdw2:41001:42001:43001:/data/mirror/gpseg1
mirror2=2:gw_sdw2:41002:42002:43002:/data/mirror/gpseg2
mirror3=3:gw_sdw2:41003:42003:43003:/data/mirror/gpseg3
mirror4=4:gw_sdw1:41000:42000:43000:/data/mirror/gpseg4
mirror5=5:gw_sdw1:41001:42001:43001:/data/mirror/gpseg5
mirror6=6:gw_sdw1:41002:42002:43002:/data/mirror/gpseg6
mirror7=7:gw_sdw1:41003:42003:43003:/data/mirror/gpseg7执行添加命令
[gpadmin@gw_mdw1 ~]$ gpaddmirrors -i addmirror
20190326:01:08:45:031106 gpaddmirrors:gw_mdw1:gpadmin-[INFO]:-Starting gpaddmirrors with args: -i addmirror
20190326:01:08:45:031106 gpaddmirrors:gw_mdw1:gpadmin-[INFO]:-local Greenplum Version: 'postgres (Greenplum Database) 4.3.1.0 build 6'
20190326:01:08:45:031106 gpaddmirrors:gw_mdw1:gpadmin-[INFO]:-master Greenplum Version: 'PostgreSQL 8.2.15 (Greenplum Database 4.3.1.0 build 6) on x86_64-unknown-linux-gnu, compiled by GCC gcc (GCC) 4.4.2 compiled on Jun 11 2014 17:23:40'命令没有报错，查看mirror节点的情况
使用gpstate -m查看，发现所有的mirror正在同步数据，因为我的集群新建，很快就同步完成了，此时再执行gpstate -m就可以看到Data Status的状态是Synchronized（已同步的）
[gpadmin@gw_mdw1 ~]$ gpstate -m
20190326:01:09:51:031359 gpstate:gw_mdw1:gpadmin-[INFO]:-Starting gpstate with args: -m
20190326:01:09:51:031359 gpstate:gw_mdw1:gpadmin-[INFO]:-local Greenplum Version: 'postgres (Greenplum Database) 4.3.1.0 build 6'
20190326:01:09:51:031359 gpstate:gw_mdw1:gpadmin-[INFO]:-master Greenplum Version: 'PostgreSQL 8.2.15 (Greenplum Database 4.3.1.0 build 6) on x86_64-unknown-linux-gnu, compiled by GCC gcc (GCC) 4.4.2 compiled on Jun 11 2014 17:23:40'
20190326:01:09:51:031359 gpstate:gw_mdw1:gpadmin-[INFO]:-Obtaining Segment details from master...
20190326:01:09:51:031359 gpstate:gw_mdw1:gpadmin-[INFO]:--------------------------------------------------------------
20190326:01:09:51:031359 gpstate:gw_mdw1:gpadmin-[INFO]:--Current GPDB mirror list and status
20190326:01:09:51:031359 gpstate:gw_mdw1:gpadmin-[INFO]:--Type = Group
20190326:01:09:51:031359 gpstate:gw_mdw1:gpadmin-[INFO]:--------------------------------------------------------------
20190326:01:09:51:031359 gpstate:gw_mdw1:gpadmin-[INFO]:- Mirror Datadir Port Status Data Status
20190326:01:09:51:031359 gpstate:gw_mdw1:gpadmin-[INFO]:- gw_sdw2 /data/mirror/gpseg0 41000 Passive Resynchronizing
20190326:01:09:51:031359 gpstate:gw_mdw1:gpadmin-[INFO]:- gw_sdw2 /data/mirror/gpseg1 41001 Passive Resynchronizing
20190326:01:09:51:031359 gpstate:gw_mdw1:gpadmin-[INFO]:- gw_sdw2 /data/mirror/gpseg2 41002 Passive Resynchronizing
20190326:01:09:51:031359 gpstate:gw_mdw1:gpadmin-[INFO]:- gw_sdw2 /data/mirror/gpseg3 41003 Passive Resynchronizing
20190326:01:09:51:031359 gpstate:gw_mdw1:gpadmin-[INFO]:- gw_sdw1 /data/mirror/gpseg4 41000 Passive Resynchronizing
20190326:01:09:51:031359 gpstate:gw_mdw1:gpadmin-[INFO]:- gw_sdw1 /data/mirror/gpseg5 41001 Passive Resynchronizing
20190326:01:09:51:031359 gpstate:gw_mdw1:gpadmin-[INFO]:- gw_sdw1 /data/mirror/gpseg6 41002 Passive Resynchronizing
20190326:01:09:51:031359 gpstate:gw_mdw1:gpadmin-[INFO]:- gw_sdw1 /data/mirror/gpseg7 41003 Passive Resynchronizing
20190326:01:09:51:031359 gpstate:gw_mdw1:gpadmin-[INFO]:--------------------------------------------------------------
查看节点状态
发现所有的mirror已经启动
postgres=# SELECT * from gp_segment_configuration ;
dbid | content | role | preferred_role | mode | status | port | hostname | address | replication_port | san_mounts
------+---------+------+----------------+------+--------+-------+----------+---------+------------------+------------
1 | -1 | p | p | s | u | 5432 | gw_mdw1 | gw_mdw1 | |
2 | 0 | p | p | s | u | 40000 | gw_sdw1 | gw_sdw1 | 43000 |
10 | 0 | m | m | s | u | 41000 | gw_sdw2 | gw_sdw2 | 42000 |
3 | 1 | p | p | s | u | 40001 | gw_sdw1 | gw_sdw1 | 43001 |
11 | 1 | m | m | s | u | 41001 | gw_sdw2 | gw_sdw2 | 42001 |
4 | 2 | p | p | s | u | 40002 | gw_sdw1 | gw_sdw1 | 43002 |
12 | 2 | m | m | s | u | 41002 | gw_sdw2 | gw_sdw2 | 42002 |
5 | 3 | p | p | s | u | 40003 | gw_sdw1 | gw_sdw1 | 43003 |
13 | 3 | m | m | s | u | 41003 | gw_sdw2 | gw_sdw2 | 42003 |
6 | 4 | p | p | s | u | 40000 | gw_sdw2 | gw_sdw2 | 43000 |
14 | 4 | m | m | s | u | 41000 | gw_sdw1 | gw_sdw1 | 42000 |
7 | 5 | p | p | s | u | 40001 | gw_sdw2 | gw_sdw2 | 43001 |
15 | 5 | m | m | s | u | 41001 | gw_sdw1 | gw_sdw1 | 42001 |
8 | 6 | p | p | s | u | 40002 | gw_sdw2 | gw_sdw2 | 43002 |
16 | 6 | m | m | s | u | 41002 | gw_sdw1 | gw_sdw1 | 42002 |
9 | 7 | p | p | s | u | 40003 | gw_sdw2 | gw_sdw2 | 43003 |
17 | 7 | m | m | s | u | 41003 | gw_sdw1 | gw_sdw1 | 42003 |
(17 rows)