Wednesday, 21 November 2012

Exalogic Virtual Tea Break Snippets - Modifying the Default Shipped (Base) Template

Having installed your Exalogic Virtual environment by default you have a single template which can be used to create your vServers. Although this template is suitable for creating simple test or development vServers it is recommended that you look at creating your own custom vServers that match the environment you wish to build and deploy. Therefore this Tea Time Snippet will take you through the simple process of modifying the standard template.

Monday, 12 November 2012

Exalogic Virtual Tea Break Snippets - Creating and using Distribution Groups

By default running your Exalogic in a Virtual provides you with, what to Cloud Users, is a single large resource and they can just create vServers and not care about how they are laid down on the the underlying infrastructure. All the Cloud Users will know is that they can create vServers. For example if we have a Quarter Rack (8 Nodes) and our Cloud User creates 8 vServers those 8 vServers may run on 8 distinct nodes or may all run on the same node.

Although in many cases we, as Cloud Users, may not be to worried how the Virtualisation Algorithm decides where to place our vServers there are cases where it is extremely important that vServers run on distinct physical compute nodes. For example if we have a Weblogic Cluster we will want the Servers with in the cluster to run on distinct physical node to cover for the situation where one physical node is lost.

To achieve this the Exalogic Virtualised implementation provides Distribution Groups that define and anti-aliasing policy that the underlying Virtualisation Algorithm will take into account when placing vServers.

It should be noted that Distribution Groups must be created before you create vServers because a vServer can only be added to a Distribution Group at creation time.