Hi Sandy,
I know it's (almost certainly) happening *way* above your level, but
dropping Oracle support on *any* database, let alone a production database,
is foolishness, and certainly *not* a cost savings, not in the long run.....
I run Oracle on EC2, w/ mail enabled, and so far, have never run into an
OOM situation. The system has to be *really* low on memory for the
kernel's OOM killer to wake up and start killing stuff. When it does,
Oracle is a big target, because it (almost certainly) is (and should be)
the big memory consumer on your (EC2) instance.
Some questions:
1.) What instance type(s) are you running? Do you have instance store
volumes configured for swap? Do you have swap configured at all? What is
the level of swap usage you are seeing?
2.) How is your Oracle memory usage configured? Do you have hugepages
configured? (Please say yes....)
3.) What do the outputs of 'free -h' and 'top' tell you? How about
'vmstat'? 'sar -B'?
-Mark
On Mon, Jan 13, 2020 at 2:33 PM Sandra Becker <sbecker6925@xxxxxxxxx> wrote:
Server: AWS EC2
RHEL: 7.6
Oracle: 12.1.0.2
We have a database on an AWS EC2 server that the OOM killer has terminated
twice in the last 5 days, both times it was the ora_dbw0_dwprod process.
On 1/8 postfix was enabled to allow us to email the DBA team through an AWS
relay server when a backup failed. We stopped running daily backups and
cronjobs that did a quick check for expired accounts. We've left postfix
enabled for sending emails. We are searching for answers but have none yet
as to why this is happening. We also no longer have Oracle support
available to us. (management saving money again).
Questions:
1. Could postfix be related to the memory issues even though we
haven't sent any emails since the first crash 5 days ago?
2. How can we monitor the memory usage of an EC2 instance?
3. How do you disable the OOM killer in EC2 should we decide to go
that route? (we have it disabled on our on-prem servers) The docs I've
found so far have not been helpful.
I appreciate any help you can give us or pointing us in the right
direction.
Thank you,
--
Sandy B.
