Log actively being archived by another process

Wed Apr 21 11:07:42 2010
ARC0: Evaluating archive log 2 thread 1 sequence 2525
ARC0: Beginning to archive log 2 thread 1 sequence 2525
Creating archive destination LOG_ARCHIVE_DEST_1: '/ora/db001/dbfra001/CIS/arch_CIS_1_2525.arc'
Wed Apr 21 11:07:44 2010
ARC1: Evaluating archive log 2 thread 1 sequence 2525
ARC1: Unable to archive log 2 thread 1 sequence 2525
Log actively being archived by another process
Wed Apr 21 11:07:45 2010
Completed checkpoint up to RBA [0x9de.2.10], SCN: 0x0000.0e41136c
Wed Apr 21 11:07:49 2010
ARC0: Completed archiving log 2 thread 1 sequence 2525

refer:

Alert中内容：

Mon Sep 03 10:12:44 2007
ARC0: Evaluating archive log 3 thread 1 sequence 31
ARC0: Beginning to archive log 3 thread 1 sequence 31
Creating archive destination LOG_ARCHIVE_DEST_1: 'D:ORACLEORADATAECOARCHIVE1_31.DBF'
Mon Sep 03 10:12:47 2007
hread 1 advanced to log sequence 33
Current log# 1 seq# 33 mem# 0: D:ORACLEORADATAECOREDO01.LOG
Current log# 1 seq# 33 mem# 1: E:ECO_DATAREDO01B.LOG
Mon Sep 03 10:12:47 2007
ARC1: Evaluating archive log 3 thread 1 sequence 31
ARC1: Unable to archive log 3 thread 1 sequence 31
Log actively being archived by another process

回想那个时间刚好执行alter system switch logfile执行了手工日志切换.另外itpub上有人也反映在使用rman执行backup加选项plus archivelog 时候会出现.

原因在于启动了多于1个的归档进程，而每个归档进程都尝试对日志文件进行归档，由于没有获得kcrrlt锁而失败，这个锁是用来保护多个归档进程归档同一日志文件，失败的归档进程将写报警信息到警告日志。

system@ECO> show parameter log_archive_max_processes

NAME TYPE VALUE
------------------------------------ ---------------------- ------------------------------
9Z#s_C a2k0log_archive_max_processes integer 2

一些深入研究参考链接：

http://www.eygle.com/archives/2007/06/log_archive_process.html
http://www.eygle.com/archives/2007/06/log_archive_process_more.html
Jn:qq-/%G0http://www.itpub.net/276117.html
http://www.dbcool.net/oracle/070729/9513/