redo logs: instantaneous switches

From: dsmcd <lookingglass_at_stopspammdormouse.net>
Date: Thu, 23 Jan 2003 19:41:48 GMT
Message-ID: <0AXX9.991$H14.42735@news.uswest.net>

Hello...

817 on Win2k.

I'm archiving & duplexing my redo logs. Certain days the logs appear to be instantaneously switching, though if I look at a log's first change # and last change #, they are different so perhaps they're not instantaneous. I can't be sure since times are in minutes not seconds. Either way, it's unexpected and worrisome.

In fact, there was one full day when I had dozens of switches every minute, all day long.

Usually, logs would switch at most two or three times on hour. There's been no added load to the system that would come close to accounting for such fast switching.

I shutdown and startup the instance each day, which may point to something in the startup or shutdown effecting the logs.

I have three groups, each with one log.

Any suggestions? This has me quite concerned.

TIA,
D.
Here's some data:

Browsing the archive folder, I'll see:

POS4T001S12148.arc     1,025KB     01/22/03 8:19pm
POS4T001S12149.arc     1,025KB     01/22/03 8:46pm
POS4T001S12150.arc     1,025KB     01/22/03 8:46pm
POS4T001S12151.arc     1,025KB     01/22/03 9:29pm
POS4T001S12152.arc     1,025KB     01/22/03 9:29pm
POS4T001S12153.arc     1,025KB     01/22/03 9:30pm
POS4T001S12154.arc     1,025KB     01/22/03 9:30pm
POS4T001S12155.arc     1,025KB     01/22/03 9:31pm
POS4T001S12156.arc     1,025KB     01/22/03 9:31pm
POS4T001S12157.arc     1,025KB     01/22/03 9:49pm
POS4T001S12148.arc     1,025KB     01/22/03 9:53pm

Looking at alert logs shows
Wed Jan 22 20:03:37 2003
ARC1: Completed archiving log# 3 seq# 12147 Wed Jan 22 20:19:02 2003
Thread 1 advanced to log sequence 12149
  Current log# 2 seq# 12149 mem# 0:
D:\ORACLE\ORADATA\POS4\REDO02.LOG
Wed Jan 22 20:19:02 2003
ARC0: Beginning to archive log# 1 seq# 12148 ARC0: Completed archiving log# 1 seq# 12148 Wed Jan 22 20:46:43 2003
Thread 1 advanced to log sequence 12150
  Current log# 3 seq# 12150 mem# 0:
D:\ORACLE\ORADATA\POS4\REDO01.LOG
Wed Jan 22 20:46:43 2003
ARC0: Beginning to archive log# 2 seq# 12149 Wed Jan 22 20:46:44 2003
Thread 1 cannot allocate new log, sequence 12151 Checkpoint not complete
  Current log# 3 seq# 12150 mem# 0:
D:\ORACLE\ORADATA\POS4\REDO01.LOG
Wed Jan 22 20:46:44 2003
ARC0: Completed archiving log# 2 seq# 12149 Wed Jan 22 20:46:46 2003
Thread 1 advanced to log sequence 12151
  Current log# 1 seq# 12151 mem# 0:
D:\ORACLE\ORADATA\POS4\REDO03.LOG
Wed Jan 22 20:46:46 2003
ARC0: Beginning to archive log# 3 seq# 12150 ARC0: Completed archiving log# 3 seq# 12150 Wed Jan 22 21:29:33 2003
Thread 1 advanced to log sequence 12152
  Current log# 2 seq# 12152 mem# 0:
D:\ORACLE\ORADATA\POS4\REDO02.LOG
Wed Jan 22 21:29:33 2003
ARC0: Beginning to archive log# 1 seq# 12151 Wed Jan 22 21:29:35 2003
Thread 1 advanced to log sequence 12153
  Current log# 3 seq# 12153 mem# 0:
D:\ORACLE\ORADATA\POS4\REDO01.LOG
Wed Jan 22 21:29:35 2003
ARC0: Completed archiving log# 1 seq# 12151 ARC0: Beginning to archive log# 2 seq# 12152 Wed Jan 22 21:29:35 2003

ARC1: Beginning to archive log# 2 seq# 12152
ARC1: Failed to archive log# 2 seq# 12152
ARC1: Beginning to archive log# 2 seq# 12152
ARC1: Failed to archive log# 2 seq# 12152

Wed Jan 22 21:29:35 2003
ARC0: Completed archiving log# 2 seq# 12152 Wed Jan 22 21:30:20 2003
Thread 1 advanced to log sequence 12154
  Current log# 1 seq# 12154 mem# 0:
D:\ORACLE\ORADATA\POS4\REDO03.LOG
Wed Jan 22 21:30:20 2003
ARC0: Beginning to archive log# 3 seq# 12153 Wed Jan 22 21:30:21 2003
Thread 1 cannot allocate new log, sequence 12155 Checkpoint not complete
  Current log# 1 seq# 12154 mem# 0:
D:\ORACLE\ORADATA\POS4\REDO03.LOG
Wed Jan 22 21:30:21 2003
ARC0: Completed archiving log# 3 seq# 12153 Wed Jan 22 21:30:24 2003
Thread 1 advanced to log sequence 12155
  Current log# 2 seq# 12155 mem# 0:
D:\ORACLE\ORADATA\POS4\REDO02.LOG
Wed Jan 22 21:30:24 2003
ARC0: Beginning to archive log# 1 seq# 12154 ARC0: Completed archiving log# 1 seq# 12154 Wed Jan 22 21:31:24 2003
Thread 1 advanced to log sequence 12156
  Current log# 3 seq# 12156 mem# 0:
D:\ORACLE\ORADATA\POS4\REDO01.LOG
Wed Jan 22 21:31:24 2003
ARC0: Beginning to archive log# 2 seq# 12155 Wed Jan 22 21:31:25 2003
Thread 1 cannot allocate new log, sequence 12157 Checkpoint not complete
  Current log# 3 seq# 12156 mem# 0:
D:\ORACLE\ORADATA\POS4\REDO01.LOG
Wed Jan 22 21:31:25 2003
ARC0: Completed archiving log# 2 seq# 12155 Wed Jan 22 21:31:26 2003
Thread 1 advanced to log sequence 12157
  Current log# 1 seq# 12157 mem# 0:
D:\ORACLE\ORADATA\POS4\REDO03.LOG
Wed Jan 22 21:31:26 2003
ARC0: Beginning to archive log# 3 seq# 12156 ARC0: Completed archiving log# 3 seq# 12156 Wed Jan 22 21:49:12 2003
Thread 1 advanced to log sequence 12158
  Current log# 2 seq# 12158 mem# 0:
D:\ORACLE\ORADATA\POS4\REDO02.LOG
Wed Jan 22 21:49:12 2003
ARC0: Beginning to archive log# 1 seq# 12157 ARC0: Completed archiving log# 1 seq# 12157 Wed Jan 22 21:53:57 2003
Thread 1 advanced to log sequence 12159
  Current log# 3 seq# 12159 mem# 0:
D:\ORACLE\ORADATA\POS4\REDO01.LOG
Wed Jan 22 21:53:57 2003
ARC0: Beginning to archive log# 2 seq# 12158 ARC0: Completed archiving log# 2 seq# 12158 Received on Thu Jan 23 2003 - 13:41:48 CST