Oracle-CDB容器数据库修改service_names踩坑
前言:
最近在对一套Oracle容器数据库进行迁移测试时,为了保持新环境与旧环境的服务名一致,需要在新环境添加旧环境的服务名,在CDB的根容器通过service_name参数添加旧环境的服务名之后,发现数据库PDB的服务名全部被注销,pdb容器也无法再正常的切换过去,因此,对容器数据库的服务名设置进行了测试,以下为测试的过程以及结果
测试环境信息:
测试环境为12.2版本,数据库唯一名为ora12,一个pdb为pdb12
SQL> show parameter unique
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
db_unique_name string ora12
SQL> show pdbs;
CON_ID CON_NAME OPEN MODE RESTRICTED
---------- ------------------------------ ---------- ----------
2 PDB$SEED READ ONLY NO
3 PDB12 READ WRITE NO
SQL>
没有手动设置过的service_names默认的服务名为ora12跟数据库的唯一名一致
SQL> show parameter service_name
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
service_names string ora12
select NAME,DISPLAY_VALUE,DEFAULT_VALUE,ISMODIFIED
from v$parameter
where name='service_names'
NAME DISPLAY_VALUE DEFAULT_VALUE ISMODIFIED
------------------------------ ------------------------------ ------------------------------ ----------
service_names ora12 NULL FALSE
此时,我们可以看到当前数据库的注册到监听的活跃服务名为cdb容器数据库的的ora12、ora12XDB以及pdb的pdb12服务
--当前我们可以看到注册的服务包括cdb的ora12以及pdb的pdb12
SQL> select con_name,name,network_name from v$active_services where NETWORK_NAME is not null;
CON_NAME NAME NETWORK_NAME
------------------------------ ------------------------------ --------------------------------------------------
CDB$ROOT ora12 ora12
CDB$ROOT ora12XDB ora12XDB
PDB12 pdb12 pdb12
[oracle@rac19a ~]$ lsnrctl status
Service "ora12" has 1 instance(s).
Instance "ora121", status READY, has 1 handler(s) for this service...
Service "ora12XDB" has 1 instance(s).
Instance "ora121", status READY, has 1 handler(s) for this service...
Service "pdb12" has 1 instance(s).
Instance "ora121", status READY, has 1 handler(s) for this service...
The command completed successfully
在容器数据库的根容器下手动设置service_names参数为ora12服务名
SQL> alter system set service_names=ora12 scope=both;
System altered.
SQL> show parameter service_names
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
service_names string ORA12
SQL>
SQL> select NAME,DISPLAY_VALUE,DEFAULT_VALUE,ISMODIFIED
2 from v$parameter
3 where name='service_names';
NAME DISPLAY_VALUE DEFAULT_VALUE ISMODIFIED
------------------------------ ------------------------------ ------------------------------ ----------
service_names ORA12 NULL SYSTEM_MOD
再次查看监听注册的服务,可以发现pdb下的pdb12服务被注销了
SQL> select con_name,name,network_name from v$active_services where NETWORK_NAME is not null;
CON_NAME NAME NETWORK_NAME
------------------------------ ------------------------------ --------------------------------------------------
CDB$ROOT ora12 ora12
CDB$ROOT ora12XDB ora12XDB
[oracle@rac19a ~]$ lsnrctl status
Service "ora12" has 1 instance(s).
Instance "ora121", status READY, has 1 handler(s) for this service...
Service "ora12XDB" has 1 instance(s).
Instance "ora121", status READY, has 1 handler(s) for this service...
The command completed successfully
这种情况下,会话手动切换到容器pdb12会出现报错ORA-44787: Service cannot be switched into,因为默认的服务为pdb容器,但由于pdb现在的默认服务pdb12被注销,所以无法正常切换过去
SQL> alter session set container=pdb12;
ERROR:ORA-44787: Service cannot be switched into.
可以通过指定CDB的根容器服务名切换过去
SQL> alter session set container=pdb12 service=ora12;
Session altered.
SQL>
SQL> show con_name
CON_NAME
------------------------------
PDB12
SQL>
那么,由于手动设置了service_names导致被注销的pdb服务名怎么恢复呢?
可以尝试通过以下四种方法进行恢复
方法一:通过在cdb根容器里面进行注册,需要将pdb12的服务名写入参数service_names进行服务注册
--在根容器下设置参数service_names,将pdb的服务名pdb12写入
SQL> alter system set service_names=ora12,pdb12 scope=both;
System altered.
--手动触发服务注册
SQL> alter system register;
System altered.
--可以看到pdb服务名重新被注册
SQL> select con_name,name,network_name from v$active_services where NETWORK_NAME is not null;
CON_NAME NAME NETWORK_NAME
------------------------------ ------------------------------ --------------------------------------------------
CDB$ROOT ora12 ora12
CDB$ROOT ora12XDB ora12XDB
PDB12 pdb12 pdb12
[oracle@rac19a ~]$ lsnrctl status
Service "ora12" has 1 instance(s).
Instance "ora121", status READY, has 1 handler(s) for this service...
Service "ora12XDB" has 1 instance(s).
Instance "ora121", status READY, has 1 handler(s) for this service...
Service "pdb12" has 1 instance(s).
Instance "ora121", status READY, has 1 handler(s) for this service...
The command completed successfully
方法二:通过dbms_service包进行pdb服务名的启动,手动开启指定的pdb服务
注:dbms_service包是Oracle服务名的管理工具,可以创建,开启,关闭指定的服务名,断开或者终止指定服务名下的连接
--首先通过指定根容器层的服务名进入到指定的pdb容器
SQL> alter session set container=pdb12 service=ora12;
Session altered.
--在pdb里面开启服务名即可
exec dbms_service.start_service('pdb12');
--可以看到pdb12被重新注册
SQL> set linesize 400
SQL> set pagesize 400
SQL> col name for a30
SQL> col CON_NAME for a30
SQL> col network_name for a50
SQL> select con_name,name,network_name from v$active_services where NETWORK_NAME is not null;
CON_NAME NAME NETWORK_NAME
------------------------------ ------------------------------ --------------------------------------------------
PDB12 pdb12 pdb12
[oracle@rac19a ~]$ lsnrctl status
Service "ora12" has 1 instance(s).
Instance "ora121", status READY, has 1 handler(s) for this service...
Service "ora12XDB" has 1 instance(s).
Instance "ora121", status READY, has 1 handler(s) for this service...
Service "pdb12" has 1 instance(s).
Instance "ora121", status READY, has 1 handler(s) for this service...
The command completed successfully
方法三,通过配置静态监听服务的方式,GLOBAL_DBNAME为pdb服务名,SID_NAME为容器数据库的实例名称,对于RAC集群要在GRID_HOME下的listener.ora配置
注意:对于通过配置静态监听服务方式连接的,通过服务名可以正常的连接到数据库,但是由于不是动态注册的服务,所以如果不指定根容器的服务名依然无法通过alter session方式切换到pdb容器,还是会出现错误ORA-44787: Service cannot be switched into.
SID_LIST_listener=
(SID_LIST=
(SID_DESC=
(GLOBAL_DBNAME=pdb12)
(ORACLE_HOME=/u01/app/oracle/product/12.0.0/dbhome_1)
(SID_NAME=ora121)
)
)
方法四,通过命令alter system reset service_names scope=both重置回滚service_names参数,重新恢复默认配置,需要注意的是,执行命令reset之后,当前service_names显示的值会变为空并且数据库依然不会注册pdb服务到监听,需要重启pdb或者实例,数据库才会重新注册pdb服务到监听
总结
通过上述手动设置service_names参数以及恢复方法测试,我们可以发现如果pdb的数量较多,需要同时去配置多个pdb 服务名,服务名的操作管理变得繁琐复杂,并且需要留意的是SERVICE_NAMES这个参数从Oracle 19c开始已经废弃后续版本将不再支持,也就是说Oracle官方对于19c版本后也开始不建议通过service_name去配置服务名
所以对于后续12c,19c数据库新增服务名的方式特别是容器数据库下,通过设置SERVICE_NAMES参数去新增服务名的方式可能并不是一个最佳的选择
那么,我们还可以通过选择哪种方式进行服务名的添加呢?
如果是RAC集群,建议通过srvctl add service 的方式进行添加高可用服务,通过集群的高可用服务可以便捷的管理数据库的服务启动,关闭以及服务模式,实现集群的服务故障转移TAF以及19c的TAC功能,
注意,无法可以通过srvctl add service方式配置跟pdb容器名称一样的服务名,会出现PRCD-1278 : The service name pdb12 cannot be same as the pluggable database default service name pdb12
--非pdb服务名的添加
srvctl add service -d db -s dbsrv -r db1 -a db2 -failovertype select -failovermethod BASIC -failoverdelay 1 -failoverretry 10
srvctl enable service -d db -s dbsrv
srvctl start service -d db -s dbsrv
--pdb服务名的添加
srvctl add service -d ora12 -s pdb12 -pdb pdb12 -r ora121 -a ora122 -failovertype select -failovermethod BASIC -failoverdelay 1 -failoverretry 10
srvctl enable service -d ora12 -s pdb12
srvctl start service -d ora12 -s pdb12
如果是单机实例,可以通过dbms_service方式进行添加,service_name表示服务名,network_name表示服务在存储在数据字典里面的网络名称,单个库里面service_name和network_name都是唯一的,不能创建重复的名称
注意:
1 非PDB的重启数据库之后,服务不会自己启动,需要手动开启
2 RAC, Oracle Restart不建议通过dbms_services进行服务管理,在cdb下面测试通过dbms_services发生服务一直无法注册到监听,pdb下面测试可以创建服务成功,所以最好还是通过srvctl进行服务的创建管理
#非pdb方式添加
exec dbms_service.create_service(service_name=>'test',network_name=>'test');
exec dbms_service.start_service('test');
#pdb实例创建
--切换到pdb里面
alter session set container=testpdb;
--创建服务名
exec dbms_service.create_service(service_name=>'testpdb1',network_name=>'testpdb1');
--开启服务名
exec dbms_service.start_service('testpdb1');
alter system register;
--保存当前pdb的状态,这样在下次重启时,服务才能自己启动
alter pluggable database save state;
最后一种方式就是通过通过配置静态监听服务的方式,GLOBAL_DBNAME为pdb服务名,SID_NAME为容器数据库的实例名称,对于RAC集群要在GRID_HOME下的listener.ora配置
--RAC集群要在GRID_HOME下的listener.ora配置
LISTENER=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=IPC)(KEY=LISTENER)))) # line added by Agent
SID_LIST_listener=
(SID_LIST=
(SID_DESC=
(GLOBAL_DBNAME=pdb12)
(ORACLE_HOME=/u01/app/oracle/product/12.0.0/dbhome_1)
(SID_NAME=ora121)
)
)
--启动之后,静态监听的服务名状态为unknown,状态为ready是数据库动态注册的
Service "pdb12" has 2 instance(s).
Instance "ora121", status UNKNOWN, has 1 handler(s) for this service...
Instance "ora121", status READY, has 1 handler(s) for this service...