Zabair,
From the AWR reports, determine peak redo
rates ..
redo log size >= peak redo rate / minute x 20 minutes
You can get more information either from the
documentation or the Redo Apply & Media
white paper published by Oracle Corp.
Rajeev
On Aug 23, 2017, at 6:58 AM, Zabair Ahmed (Redacted sender "roon987" for
DMARC) <dmarc-noreply@xxxxxxxxxxxxx> wrote:
Hello,
11.2.0.4 EE on 4 node RAC Redhat 6.6 Cluster.
We are constantly seeing "Checkpoint not complete" message in the alert log:
Thread 2 cannot allocate new log, sequence 109658
Checkpoint not complete
Current log# 26 seq# 109657 mem# 0:
+ARCH01/prd/onlinelog/group_26.393.904013409
Current log# 26 seq# 109657 mem# 1:
+ARCH01/prd/onlinelog/group_26.634.904013411
Thread 2 advanced to log sequence 109658 (LGWR switch)
Tue Aug 22 00:03:06 2017
LNS: Standby redo logfile selected for thread 2 sequence 109658 for
destination LOG_ARCHIVE_DEST_2
Current log# 3 seq# 109658 mem# 0:
+ARCH01/prd/onlinelog/group_3.263.877611157
Current log# 3 seq# 109658 mem# 1:
+ARCH01/prd/onlinelog/group_3.273.877680615
Tue Aug 22 00:03:11 2017
Archived Log entry 510017 added for thread 2 sequence 109657 ID 0x1b7b9f46
dest 1:
Tue Aug 22 00:11:39 2017
Thread 2 cannot allocate new log, sequence 109659
Checkpoint not complete
Current log# 3 seq# 109658 mem# 0:
+ARCH01/prd/onlinelog/group_3.263.877611157
Current log# 3 seq# 109658 mem# 1:
+ARCH01/prd/onlinelog/group_3.273.877680615
Thread 2 advanced to log sequence 109659 (LGWR switch)
Current log# 22 seq# 109659 mem# 0:
+ARCH01/prd/onlinelog/group_22.744.904009995
Current log# 22 seq# 109659 mem# 1:
+ARCH01/prd/onlinelog/group_22.931.904009999
Tue Aug 22 00:11:44 2017
LNS: Standby redo logfile selected for thread 2 sequence 109659 for
destination LOG_ARCHIVE_DEST_2
Tue Aug 22 00:11:50 2017
Archived Log entry 510019 added for thread 2 sequence 109658 ID 0x1b7b9f46
dest 1:
Tue Aug 22 00:21:55 2017
Thread 2 cannot allocate new log, sequence 109660
Checkpoint not complete
Current log# 22 seq# 109659 mem# 0:
+ARCH01/prd/onlinelog/group_22.744.904009995
Current log# 22 seq# 109659 mem# 1:
+ARCH01/prd/onlinelog/group_22.931.904009999
Thread 2 advanced to log sequence 109660 (LGWR switch)
Current log# 4 seq# 109660 mem# 0:
+ARCH01/prd/onlinelog/group_4.265.877611161
Current log# 4 seq# 109660 mem# 1:
+ARCH01/prd/onlinelog/group_4.274.877680623
Tue Aug 22 00:22:00 2017
LNS: Standby redo logfile selected for thread 2 sequence 109660 for
destination LOG_ARCHIVE_DEST_2
Tue Aug 22 00:22:09 2017
Archived Log entry 510026 added for thread 2 sequence 109659 ID 0x1b7b9f46
dest 1:
Tue Aug 22 00:30:36 2017
Thread 2 cannot allocate new log, sequence 109661
Checkpoint not complete
Current log# 4 seq#
Also ASH Report listing "log file switch (checkpoint incomplete)" as the Top
User Event.
All this is indicating that we have redo logs which are incorrectly sized.
My question is how do you determine the correct redo log size? Currently the
redo log size 1.5GG in all 4 instances.
Can you mix and match different redo log size for different instances? Is
this recommended? We are getting the "Checkpoint not complete" message only
on Instance 2!
Are there any disadvantages in having different redo log sizes for different
instances? Do other people do this? Or should we keep the redo log size the
same across all 4 instances?
We are also running this in a DataGuard environment.
Appreciate any feedback.
Thanks
