ARCn: Log actively being archived by another process

今天去關心我親愛的資料庫時，發現他在凌晨兩點相當勤奮的狂丟archive log出來= = 行為相當怪異，所以就去翻翻alert log看看是否有怪訊息，看看似乎也沒什麼error，就是在那個時間相當密集的出現如下訊息:

ARCn: Beginning to archive log# 2 thrd# 1 seq# 24

ARCn: Unable to archive log# 2 thrd# 1 seq# 24

Log actively being archived by another process

嗯... what happened XD?!

再Ask Tom裡找了一些相關文章，其中有某篇算是回答了我的問題:

It is just a side effect of having more then one archiver.

If automatic archiving is turned on then all of the archiver process will try to archive this logfile, however they will not be able to aquire the lock 'kcrrlt', the lock to protect multiple arch processes from archiving the same logfile.

The failing process process will write to the trace/alert message that it was unable to archive the logfile.

The file is successfully archived by some other process.

嗯... 所以其實好像，也沒什麼XD，後來我發現這樣的訊息一直都會出現啦~ 只是沒有像今天凌晨一直連續出現。所以其實問題應該是... "凌晨兩點幹嘛一直勤勞的丟log!? 是誰一直在用系統@_@!?" 這樣XD

好哩~ 這個問題就到這邊。原本看了一些文件想整理一下，不過現在好懶= = 就先這樣吧~ :P

Ref:

1. [Ask Tom] ARC1: Beginning to archive log# 1 seq# 56947