greenplum 單獨添加 standby
本文主要介紹如何爲沒有做Standby的Master節點添加Standby。（快速整理版）
舊版本gp集羣需要注意！！！！
在爲Master節點搭建Standby的過程中，GreenPlum會自動關閉數據庫，並以utility模式打開Master節點，然後修改gp_segment_configuration字典中增加Standby的信息，然後再關閉Master節點，將Master的數據拷貝到Standby節點，最後啓動數據庫，所以，在爲Master節點添加Standby時，需要在空閒時段進行，否則會影響業務。
添加新節點需要完成如下工作：
參考信息：
http://blog.51cto.com/michaelkang/2167195
1：新建gp 用戶，用戶id 與集羣節點保持一直；
2：新建數據目錄，chown gpadmin.gpadmin $DIR；
3：集羣所有主機(Master節點和所有Segment節點)的hosts文件均需要添加Standby主機的信息。
4：完成系統初始化（關閉防火牆，selinux ，sysctl.conf ,limits.conf ...），具體參考greenplum 集羣安裝初始化安裝步驟；
5：直接打通master節點 ssh 免密登陸新添加standby ；
6：standby節點 ssh 免密登陸集羣其它節點,通過gpssh工具測試；
7：安裝greenplum 軟件包
8：檢查新添加standby 節點安裝目錄權限，chown gpadmin.gpadmin $DIR
9：設置standby 節點gpadmin賬戶的環境變量，使之生效；
以上確認配置沒問題後：
10.在Master節點通過gpinitstandby命令添加Standby。 （gpadmin 用戶執行）
[gpadmin@mdw config]$ gpinitstandby -s standby-node操作實例：
[gpadmin@kangjianhua-6-16 ~]$ gpinitstandby -s kangjianhua-6-15.ptmind.com
gpadmin-[INFO]:-Validating environment and parameters for standby initialization...
gpadmin-[INFO]:-Checking for filespace directory /usr/local/gpdata/gpmaster/gpseg-1 on kangjianhua-6-15.ptmind.com
gpadmin-[INFO]:------------------------------------------------------
gpadmin-[INFO]:-Greenplum standby master initialization parameters
gpadmin-[INFO]:------------------------------------------------------
gpadmin-[INFO]:-Greenplum master hostname = kangjianhua-6-16.ptmind.com
gpadmin-[INFO]:-Greenplum master data directory = /usr/local/gpdata/gpmaster/gpseg-1
gpadmin-[INFO]:-Greenplum master port = 5432
gpadmin-[INFO]:-Greenplum standby master hostname = kangjianhua-6-15.ptmind.com
gpadmin-[INFO]:-Greenplum standby master port = 5432
gpadmin-[INFO]:-Greenplum standby master data directory = /usr/local/gpdata/gpmaster/gpseg-1
gpadmin-[INFO]:-Greenplum update system catalog = On
gpadmin-[INFO]:------------------------------------------------------
gpadmin-[INFO]:- Filespace locations
gpadmin-[INFO]:------------------------------------------------------
gpadmin-[INFO]:-pg_system -> /usr/local/gpdata/gpmaster/gpseg-1
Do you want to continue with standby master initialization? Yy|Nn (default=N):
> y
gpadmin-[INFO]:-Syncing Greenplum Database extensions to standby
gpadmin-[INFO]:-The packages on kangjianhua-6-15.ptmind.com are consistent.
gpadmin-[INFO]:-Adding standby master to catalog...
gpadmin-[INFO]:-Database catalog updated successfully.
gpadmin-[INFO]:-Updating pg_hba.conf file...
gpadmin-[INFO]:-pg_hba.conf files updated successfully.
gpadmin-[INFO]:-Updating filespace flat files...
gpadmin-[INFO]:-Filespace flat file updated successfully.
gpadmin-[INFO]:-Starting standby master
gpadmin-[INFO]:-Checking if standby master is running on host: kangjianhua-6-15.ptmind.com in directory: /usr/local/gpdata/gpmaster/gpseg-1
20181115:18:06:06:176421 gpinitstandby:kangjianhua-6-16:gpadmin-[WARNING]:-Unable to cleanup previously started standby:
20181115:18:06:07:176421 gpinitstandby:kangjianhua-6-16:gpadmin-[INFO]:-Cleaning up pg_hba.conf backup files...
20181115:18:06:08:176421 gpinitstandby:kangjianhua-6-16:gpadmin-[INFO]:-Backup files of pg_hba.conf cleaned up successfully.
20181115:18:06:08:176421 gpinitstandby:kangjianhua-6-16:gpadmin-[INFO]:-Successfully created standby master on kangjianhua-6-15.ptmind.comgpcc 問題處理：
greenplum master 節點遷移後，gpcc節點的配置要需要修改gpcc 連接節點的指向新的master地址：
gp 集羣master切換後，需要修改：
/usr/local/gpcc/greenplum-cc-web-4.3.1/conf
cp app.conf app.conf.bak
vim app.conf
[gpadmin@kangjianhua-6-16 conf]$ more app.conf
appname = gpccws
listentcp4 = true
runmode = prod
session = true
enablexsrf = true
xsrfexpire = 2592000
xsrfkey = 61oETzKXQAGaYdkLxxxxxxxxxxxxxx
rendertype = json
printallsqls = false
master_port = 5432
path = /usr/local/gpcc
display_name = gpcc
enable_kerberos = false
EnableHTTPS = false
EnableHTTP = true
httpport = 28080
rpc_port = 8899
master_host = kangjianhua-6-15.ptmind.com ==> kangjianhua-6-16.ptmind.com (新master) 《《《===修改內容
查看狀態：
gpcc status
啓動服務：
gpcc start
#查看服務進程：
ps -ef|grep ccagent
/usr/local/gpcc/greenplum-cc-web-4.3.1/bin/ccagent -udpport 9898 -rpcaddr kangjianhua-6-15.ptmind.com:8899
安裝參考：
http://blog.51cto.com/michaelkang/2170631