創建數據庫會默認創建與數據庫同名的service，默認的service實現所有實例的負載均衡，可以認為數據庫的所有實例是默認創建的service的首選節點。

手工創建的service資源區分首選節點與備用節點，客戶端無論通過哪個節點請求連接都會固定連接到service資源的首選節點，只有當首選節點故障才會連接到備用節點。

創建service資源

[oracle@king01 ~]$ srvctl add service -d king -s sale -r king1 -a king2 -P basic -e session -m basic -w 5 -z 3

-d：數據庫名稱

-s：新創建的service名稱

-r：首選節點列表

-a：備用節點列表

-P：TAF策略

-y：是否自動啟動

-e：TAF類型

-z：在failover之前重新嘗試連接的次數

-w：在failover之前兩次嘗試連接的時間間隔

查詢service資源屬性

[oracle@king01 ~]$ srvctl config service -d king -s sale

Service name: sale

Service is enabled

Server pool: king_sale

Cardinality: 1

Disconnect: false

Service role: PRIMARY

Management policy: AUTOMATIC

DTP transaction: false

AQ HA notifications: false

Failover type: SESSION

Failover method: BASIC

TAF failover retries: 3

TAF failover delay: 5

Connection Load Balancing Goal: LONG

Runtime Load Balancing Goal: NONE

TAF policy specification: BASIC

Edition:

Preferred instances: king1

Available instances: king2

查詢service資源狀態

[oracle@king01 ~]$ srvctl status service -d king

Service sale is not running.

啟動service資源

[oracle@king01 ~]$ srvctl start service -d king -s sale

[oracle@king01 ~]$ srvctl status service -d king

Service sale is running on instance(s) king1

col username for a20
col failed_over for a15
SQL> select inst_id,username,failover_type,failover_method,failed_over from gv$session where username = 'TPCC';
   INST_ID USERNAME             FAILOVER_TYPE                           FAILOVER_METHOD                FAILED_OVER
---------- -------------------- --------------------------------------- ------------------------------ ---------------
         1 TPCC                  SESSION                                 BASIC                          NO
SQL> select inst_id,username,failover_type,failover_method,failed_over from gv$session where username = 'TPCC';
   INST_ID USERNAME             FAILOVER_TYPE                           FAILOVER_METHOD                FAILED_OVER
---------- -------------------- --------------------------------------- ------------------------------ ---------------
         2 TPCC                  SESSION                                 BASIC                          YES

Oracle RAC Service資源管理