Tuesday, December 11, 2007

Agent Update Packs

If you navigate to the 'Managed Software' page in the quick links you'll see a listing of all the tools releases and JDBC drivers that have been uploaded to the management console. These packages, obtained from the Update Center, are used to stage tools releases prior to installing or upgrading them.

You may notice an entry named 'Agent Install Pack 7' of type 'Management Agent Installer Bundle'.

What is this? Well, in a previous post I mentioned that we have two separate downloads for Server Manager for each tools release.
  • A large (~1 GB) Installer, and
  • A much smaller (< 50 MB) console update
The large installer is used the first time you install SM. This includes the J2EE container used to run the web application, the SM management console application, and the corresponding agent install pack. The SM update contains only updated SM management console (and corresponding management agent code). Installing a new SM application and later applying an update is functionally equivalent to initially installing the later release using the installer. Our goal here was to keep updates small and easy to apply.

There's actually a third possible download from the update center: a new agent update pack. This contains items that are rarely going to change with each tools release update. Specifically it contains the platform specific managed home installer for all the platforms we support and the platform specific Oracle Configuration Manager agent that is installed along with the managed home.

These items are rarely updated because
  1. The managed home agent installer obtains the actual agent codebase from the management console, thus installing whatever is current with the console application
  2. The Oracle Configuration Manager agent will automatically update with the latest version provided by Oracle, therefore not requiring OCM updates with Server Manager
So why the potential separate download for the management agent pack? In the event we need to update either the managed home installer or OCM agent that is initially installed we will create a new management agent pack that can be downloaded from the Update Center. Why would we do this? It won't be typical, but an example in which we might need to update the pack is if we added support for a new platform that isn't currently available or need to deploy code fixes to the managed home installer. As of this posting we have no foreseeable need to update the agent installer pack.

How do I know if I need a new agent installer pack? Should we need to update the agent installer pack we will create and add the package to the Update Center. Navigating to the 'Management Agents' page will tell you if a new agent installer pack is required. For example, assume:
  1. We updated the agent install pack with a particular tools release of Server Manager
  2. You have applied that SM update to an existing SM installation
  3. You want to install a new managed home agent
In this case you will be instructed to download the corresponding agent installer pack and add it to the SM software repository.

What if I delete the existing agent installer pack? This software component is treated just like any other software component; that is you can delete it either through SM or directly from the file system. If you have deleted the agent installer pack and navigate to the 'Management Agents' screen you will be instructed to obtain the installer pack from the Update Center.

Since we have not had the need to rev the installer pack it is not currently available for download from the Update Center. So, in the case you accidentally deleted the existing installer package you may obtain it only by performing a new SM installation and copying/uploading the file from the new install to the existing installation. After doing so you may uninstall the new SM console just installed.

The file will be named something along the lines of agentPackage7.jar and will be located in the directory INSTALL_BASE/components, where INSTALL_BASE refers to the installation path of the SM application.