物理備庫無法接受archivelog

兩天碰到兩起類似事件

昨天的情況是 一套物理備庫 備庫alert顯示於1月3號同主庫的連線終止，從那之後再也沒有接受到歸檔日誌；

登陸主庫，發現tnsping備庫可以連通，log_archive_dest_n_2為enable； 備庫的監聽器正常工作，且v$archive_gap沒有記錄； 使用的是arch模式傳輸；

後來經過一系列除錯，嘗試增大主庫的log_archive_max_processes值，由2加大到4，然後問題解決了

對此，metalink上有篇相關的文章。

今天又是同樣的問題，不同的是主庫是兩節點RAC，其中一個節點的日誌可以正常傳輸，另一個死活不行；兩個節點的配置是一樣的，加大log_archive_max_processes，由2到6，該節點還是無法傳輸日誌到備庫；

最後只能手工傳輸並發現了問題，原來出問題的節點與備庫之間的網路出現問題，scp時候只傳輸1秒就會斷開，難怪日誌一直無法傳輸到備庫。

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Applies to:

Oracle Server - Enterprise Edition - Version: 10.2.0.1 to 10.2.0.3
This problem can occur on any platform.

Symptoms

In a Data Guard Configuration, during Scheduled RMAN Backup no Redo is transported to the Standby Server as the ARCH Process is blocked (as expected ie. RMAN would utilize 1 ARCn Process and the other ARCn for local Archiving ) which means the Standby stays out of sync (assuming max_arch_processes=2) until the ArchiveLog is manually copied across and registered to the Standby Database after which the Standby Database resumes applying the ArchiveLogs .

Standby alert log: 
RFS[28]: Assigned to RFS process 4092 
.... 
Fri Nov 09 16:24:48 2007 
RFS[28]: Possible network disconnect with primary database 

 Primary alert log: 
LNS1 started with pid=20, OS id=6020 
.... 
Fri Nov 09 16:26:17 2007 
Committing creation of archivelog 
'E:\ORADATA\EMPOWER\ARCH\ARC10374_0619028071.001' 
Failed to send message to ARCH process (function = 0xa) 
LNS1 started with pid=20, OS id=2800

Cause

All RFS disconnects are caused by the Death of their associated LNS Process .

The Primary does not have enough ARCn Processes. that one has got stuck for some Reason leaving no other ARCn Processes to ship FAL Requests (One ARCH only serves LOCAL destinations).

Also if an ARCn-Process gets stuck, you can simply kill it using an OS-Kill. This has no Impact on the Database itself since the PMON-Process will restart it automatically

Solution

Please ensure you set the LOG_ARCHIVE_MAX_PROCESSES Initialization Parameter at least to the recommended Value of 4 when using a Data Guard Configuration, depending on the Setup even more Archive Processes might be required.