Re: ADG lag after upgrading to 12.1
- From: Rich J <rjoralist3@xxxxxxxxxxxxxxxxxxxxx>
- To: oracle-l@xxxxxxxxxxxxx
- Date: Mon, 18 Mar 2019 08:18:09 -0500
On 2019/03/17 14:58, Neil Chandler wrote:
A lag of 20-30 seconds seems very high on the same server, with no network
latency. What resource contention do you have on the server? Any CPU
starvation? Slow disk?
I'm thankfully swimming in CPU -- 4 core POWER7, SMT4, hanging around
20% utilization with peaks below 60%, except when parallel RMAN
incremental backups hit their daily run. Disk is XIV SAN, where I don't
come near my pre-live tests of 4-5GBs with a 50/50 read/write split.
Basically, no hardware performance issues -- I've been spoiled there...
:)
But since this hasn't changed for 5 years, it seems highly likely to be
something related to the DB upgrade.
Any chance you could provide the config?
Show configuration verbose
Show database verbose "dbname"
I don't run the broker for various reasons, including issues I had at
setup 5 years ago with EM12c BP1, IIRC. But maybe these 2 queries run
from the Primary will give you what you're looking for:
SELECT
vd.database_role,
vd.force_logging,
vd.flashback_on,
vd.log_mode,
vd.open_mode,
vd.guard_status,
vd.protection_mode,
vd.switchover_status,
vad.dest_id
FROM
v$database vd, v$archive_dest vad
WHERE
vad.target = 'STANDBY';
DATABASE_ROLE
FORCE_LOGGING
FLASHBACK_ON
LOG_MODE
OPEN_MODE
GUARD_STATUS
PROTECTION_MODE
SWITCHOVER_STATUS
DEST_ID
PRIMARY
YES
NO
ARCHIVELOG
READ WRITE
NONE
MAXIMUM PERFORMANCE
TO STANDBY
2
SELECT
ad.dest_id,ad.status,ad.target,ad.archiver,ad.process,ad.register,ad.transmit_mode,gap_status
FROM v$archive_dest ad JOIN v$archive_dest_status ads ON ad.dest_id =
ads.dest_id
WHERE ad.dest_id = 2;
DEST_ID
STATUS
TARGET
ARCHIVER
PROCESS
REGISTER
TRANSMIT_MODE
GAP_STATUS
2 VALID
STANDBY
LGWR
LGWR
YES
ASYNCHRONOUS
NO GAP
Do you have figures for the amount of redo produced at 11.2 and 12.1 ?
Hmmm, that sounds like a metric I should be actively monitoring, but am
not. This might be in my EM repository, but a quick look at
V$ARCHIVED_LOG shows no big difference after the upgrade, with an
average of about 64GB/day.
Thoughts?
Thanks!
Rich
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