enterprise-manageroracleoracle-11g-r2
I setup the OEM with the Idea to receive Critical messages (emails when the DB, listener, agents and host are down/up) but it doesn't seem to be working. If I "shutdown abort" the database I wont received any message until I put it up and running, so I receive all the messages together.
Please see image Bellow, that's how I set the alerts, I tested the Email sending and it's working.
Benoit, you actually had a partial answer, everything you said was correct, but after next reboot, the account locked. After several hours of more research, the following issue was discovered, with the appropriate resolution.
Enterprise Manager had the default SYSMAN password stored for its credentials, and was trying to lock in with that password in rapid succession (300 times a minute or so according to the Event Log). Hence, after several rapid tries with the same wrong password, Oracle locks the account.
Setting a new password in SQL*PLUS or SQL Developer doesn't reset the password used to login to Enterprise Manager, to reset the password in enterprise manager, you need to open a command prompt and do the following:
emctl config oms sso -remove
emctl stop oms
emctl start oms
During the above commands, it'll prompt you for the current SYSMAN password, which you can enter, and it should remove the SYSMAN password used by your Enterprise Manager Console, replacing it with the one you just entered.
As it turns out, the ODA is factory configured with active-backup bonds. I've tested this to work well without any switch-side LACP/EtherChannel configuration, and each bonded connection may be split across two switches. In my tests, no simulated failure or network reconfiguration caused more than a a few hundred milliseconds worth of network outage.
This means that one can set up an isolated redundant front network for web applications using any layer two switches that are not inherently redundant.
To avoid client connections taking the long way into the company network and back through the other switch (and thus making production dependent on that equipment), one can have a private VLAN that only lives on the two edge switches and on an EtherChannel trunk between them.
As such, only the application servers and the database appliance will exist on that virtual network segment.
I don't see a way to control which path the connections from the application servers take to the database listeners, so the link between the two switches will have to be redundant, less this link becomes a single point of failure. This rules out using unmanaged switches without support for VLAN and either LACP or STP.
Using Cisco Catalyst 2960-series switches, I believe a combination of EtherChannel and Port Fast would be the better choice for a solid independent connection between the two. I would also use Port Fast on the ports for all the bonded connections to ODA and application servers.
Since the production network is isolated, one would need separate network connections for management, backup and connectivity to the rest of the company network.
Naturally, in order for this front production network to be fully self contained, any dependencies to external resources, such as DNS or authentication services, must also be resolved. Ideally production would be able to continue independently, without regard to any faults, ongoing maintenance or network outages anywhere else in the data center or company network.
Best Answer
And that is why Enterprise Manager Database Control is inappropriate for this kind of monitoring. Enterprise Manager Grid Control/Cloud Control runs on a seperate host, with a seperate repository database, and that is the tool for this job.