在某些rac情况下需要,需要对数据库默认的db_name对应的服务名进行修改,实现优先节点访问的效果.分析了下在默认值情况下,db_name影响到db_unique_name,然后决定了数据库的service_names.现有库的db_name无法修改,那就只能在db_unique_name上做手脚(只是修改service_names,对应的db_unique_name还是会创建默认服务,这样该服务依旧可以连接).但是在rac环境中db_unique_name记录到了crs资源之中,无法直接在数据库级别修改(修改会报ORA-32017 ORA-65500错误)

SQL> alter system set db_unique_name='nxifenfei' sid='*' scope=spfile;
alter system set db_unique_name='nxifenfei' sid='*' scope=spfile
*
ERROR at line 1:
ORA-32017: failure in updating SPFILE
ORA-65500: could not modify DB_UNIQUE_NAME, resource exists

只能先删除crs中关于db的资源,然后再进行修改服务名,再增加db资源

[oracle@xffdb1 ~]$ srvctl remove database -d xifenfei  -f

SQL> alter system set db_unique_name='nxifenfei' sid='*' scope=spfile;

[oracle@xffdb1 ~]$ srvctl add database -d nxifenfei -o /u01/app/oracle/product/19c/db_1 -p \
  +DATADG/XIFENFEI/PARAMETERFILE/spfile.271.1174153165 -pwfile +DATADG/XIFENFEI/PASSWORD/pwdxifenfei.256.1174152463
[oracle@xffdb1 ~]$ srvctl add instance -d nxifenfei -i xifenfei1 -n xffdb1
[oracle@xffdb1 ~]$ srvctl add instance -d nxifenfei -i xifenfei2 -n xffdb2
[oracle@xffdb1 ~]$ srvctl add instance -d nxifenfei -i xifenfei3 -n xffdb3

创建新服务(和db_name同名,和现在的db_unique_name不同名)

[oracle@xffdb1 ~]$ srvctl add service -db nxifenfei -service xifenfei -r xifenfei2 -a xifenfei1,xifenfei3 \
  -failovertype SESSION -failovermethod BASIC -failoverdelay 10 -failoverretry 3 -failback YES
[oracle@xffdb1 ~]$ srvctl start service -db nxifenfei -service xifenfei

[oracle@xffdb1 ~]$ srvctl config service -d nxifenfei -service xifenfei
Service name: xifenfei
Server pool:
Cardinality: 1
Service role: PRIMARY
Management policy: AUTOMATIC
DTP transaction: false
AQ HA notifications: false
Global: false
Commit Outcome: false
Failover type: SESSION
Failover method: BASIC
Failover retries: 3
Failover delay: 10
Failover restore: NONE
Connection Load Balancing Goal: LONG
Runtime Load Balancing Goal: NONE
TAF policy specification: NONE
Edition:
Pluggable database name:
Hub service:
Maximum lag time: ANY
SQL Translation Profile:
Retention: 86400 seconds
Failback :  yes
Replay Initiation Time: 300 seconds
Drain timeout:
Stop option:
Session State Consistency: DYNAMIC
GSM Flags: 0
Service is enabled
Preferred instances: xifenfei2
Available instances: xifenfei1,xifenfei3
CSS critical: no
Service uses Java: false
[grid@xffdb1 ~]$

服务的其他操作

--调整服务的优先节点
srvctl modify service -db nxifenfei -service xifenfei -modifyconfig -preferred "xifenfei1" -available "xifenfei2,xifenfei3"
srvctl stop service -db nxifenfei -service xifenfei 
srvctl start service -db nxifenfei -service xifenfei 

--切换服务所在节点
srvctl relocate service -db nxifenfei -service xifenfei -oldinst xifenfei2 -newinst xifenfei1

--删除服务
srvctl stop service -db nxifenfei -service xifenfei
srvctl remove service -db nxifenfei -service xifenfei