This is part 2 of a three-part blog series that summarizes the most commonly implemented configuration changes to improve performance and operation of a large Enterprise Manager 12c environment. A “large” environment is categorized by the number of agents, targets and users. See the Oracle Enterprise Manager Cloud Control Advanced Installation and Configuration Guide chapter on Sizing for more details on sizing your environment properly.
The entire series can be found in the My Oracle Support note titled id=1553342.1">Oracle Enterprise Manager 12c Configuration Best Practices [1553342.1].
By design WLS will ping applications and wait for a response for up to the value of Stuck Thread Max Time which is set to 600 seconds by default. This is a heartbeat to ensure that a particular thread is not stuck. EM on the other hand will keep threads running as long as there is work in the queue and they will not respond to a heartbeat. This is expected behavior for both EM and WebLogic Server however it will cause WLS to timeout and error which will create an incident within EM. If this parameter is not increased, the number of incidents created by this WLS error can be significant. Below is an example of the incident that may be seen. Please note, an enhancement bug has been created requesting that EM install out of the box with a higher value for this parameter.
Recommendation: To assist in reducing these errors, increase the stuck thread timeout in the Admin server as per the steps below. Note that this will reduce the number of above alerts but may not remove them completely.
1. Log onto the WLS Admin server.
2. Click on Environment in the top right side menu and expand Servers. Click on one of the OMS server names.
3. Click on the Tuning tab on in the middle window and then on the Lock and Edit under the Change Center (top left).
4. Change the value for Stuck Thread Max Time to 1800.
5. Save and Activate the change. This will require a restart of the OMS server for it to go into effect and will need to be repeated for all servers in the Admin Console (i.e. OMS servers and ADMINSERVER) but only needs to be done once per site/domain. If the environment contains standby OMS servers, repeat these steps for all standby OMS servers and the ADMINSERVER although a reboot is not required for the standby OMS servers as they are not running.
The default severity setting for logging information in the WebLogic Server is set at a level that will create excessive logging data. These settings should be set to a higher severity level.
Recommendation: To modify these settings, follow the steps below:
1. Log onto the WLS Admin server.
2. Click on Environment in the top right side menu and expand Servers. Click on the first OMS server.
3. Click on the Logging tab in the middle window and then on the Lock and Edit under the Change Center (top left).
4. Expand the Advanced option at the bottom of the page.
5. Change the Minimum log severity from Info to Warning.
6. Change the Domain Log Broadcaster Severity Level from Notice to Error.
7. Save and Activate the change. This does not require a restart of the OMS server for it to go into effect but will need to be repeated for all servers in the Admin Console (i.e. OMS servers and ADMINSERVER. This change only needs to be done once per site/domain. If the environment contains standby OMS servers, repeat these steps for all standby OMS servers and the ADMINSERVER.