Oracle 10g RAC遠端連線ORA-12545錯誤根因與解決方案

現象描述

遠端客戶端透過統一服務名連線RAC叢集時，間歇性出現ORA-12545: 因目標主機或對象不存在, 連接失敗，重試幾次又正常，極不穩定。

客戶端TNS配置

nuagerac =
(DESCRIPTION =
  (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.127)(PORT = 1521))
  (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.128)(PORT = 1521))
  (LOAD_BALANCE = yes)
  (CONNECT_DATA =
    (SERVER = DEDICATED)
    (SERVICE_NAME = nuagerac)
    (FAILOVER_MODE = (TYPE = SELECT)(METHOD = BASIC)(RETRIES = 180)(DELAY = 5))
  )
)

根因分析 (Oracle Note 364855.1)

RAC環境下，Listener將連線重導向至節點VIP，但節點回報的LOCAL_LISTENER參數若為主機名而非IP，或與REMOTE_LISTENER不一致，導致客戶端解析失敗，拋出ORA-12545。

解決方案：設定各節點LOCAL_LISTENER為具體IP

-- 節點1 (nuage1)
CONN SYS@nuage1 AS SYSDBA
ALTER SYSTEM SET LOCAL_LISTENER = '(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.127)(PORT = 1521))' SID = 'nuage1';

-- 節點2 (nuage2)
CONN SYS@nuage2 AS SYSDBA
ALTER SYSTEM SET LOCAL_LISTENER = '(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.128)(PORT = 1521))' SID = 'nuage2';

驗證結果

修改後連續測試8次連線，零錯誤，問題徹底解決。

環境資訊

• Oracle版本：10.2.0.4
• 作業系統：Red Hat AS 4.5

補充：Oracle官方將此歸類為PROBLEM而非Bug。若環境使用SCAN Listener (11gR2+)，請改設定REMOTE_LISTENER指向SCAN VIP。