Oracle Enterprise Manager 12c Server Sizing Guide

Oracle Enterprise Manager 12c server sizing is calculated by:

a) total number of managed agents and targets

b) the future growth of your Oracle Enterprise Manager environment

c) your organization's high availability requirements.

For example, if you know the total number of managed agents and targets, sizing WebLogic and the Oracle database is as simple as following Table 2, Table 3 and Table 4. As you add more agents and targets, it is important to consider the future growth of your Oracle Enterprise Manager environment as well as the ability to scale up or to scale out with additional CPU, RAM and storage.

In the image bellow we see the minimum physical memory and storage requirements for the WebLogic server hosting the Oracle Management Service and the Oracle Management Agent. To use BI Publisher add 1.5 GB of RAM

In the image bellow we see the recommended Oracle Management Service minimum RAM and CPU cores requirements for WebLogic along with the recommended number of WebLogic hosts for a small, medium and large number of agents and targets.

In the image bellow we see the minimum RAM, CPU cores, storage and the number of hosts for the database server hosting the Oracle Management Repository

The Oracle Management Repository, the Oracle Management Service along with the Oracle Management Agent can be installed on a single host in an all-in-one configuration for evaluations or in an n-tier configuration for production. Traditionally, production Oracle Enterprise Manager environments are not be placed on a single server, nor should the Oracle Management Repository be shared with production or test databases on the same server. For production, the Oracle Management Repository as well as WebLogic should be on dedicated virtual or physical servers. If your Oracle Enterprise Manager environment starts out small, make sure to have a plan to scale out your Oracle Enterprise Manager infrastructure.

For the Oracle Management Repository, scaling out means moving to RAC for the Oracle Management Repository database. An important consideration when scaling out an Oracle Enterprise Manager environment, is to determine if the underlying hardware where the Oracle Management Repository database runs is capable to transition to RAC? If the hardware is not capable to transition to RAC, it is possible to move and/or export the Oracle Management Repository database to a different system with more resources. If the Oracle Management Repository is hosted on an Oracle VM virtual machine, transitioning to RAC is a trivial operation.

Scaling out the WebLogic and Oracle Management Service tier entails adding a load balancing (SLB) solution to front end multiple WebLogic servers hosting the Oracle Management Service. Adding a load balancer with additional WebLogic servers introduces a virtual host name for the WebLogic cluster. Introducing a virtual host name into an existing Oracle Enterprise Manager environment will require a reconfiguration of all of your Oracle Management Agents to resolve to the new virtual host name. Reconfiguring a couple Oracle Management Agents is no trouble, although re configuring a lot of Oracle Management Agents would demand a long service window. When you deploy Oracle Enterprise Manager, consider using a virtual host name for the web tier.