[Editor: This is the fifth of a five-part series on virtualization and cloud topics from Ivo Dujmovic, an architect in our Applications Technology Integration group.]
Breaking news: you can now achieve live migration of E-Business Suite instances on Oracle VM (OVM). This is the High Availability and Fault Tolerance Holy Grail. In an environment configured to support live migration, end-user sessions running on one node in a virtual machine server can be migrated transparently to a different node on a different virtual machine server. You have asked for this functionality for more than a dozen years and many Oracle partners offer solutions to achieve this.
After all these years, Oracle can provide you a solution for E-Business Suite environments using Oracle VM. Why was this so hard for Oracle E-Business Suite? Well, the short answer is that we have hundreds of products using many different technologies as part of the E-Business Suite, and many of them had complicated session state handling (some in the database, some on the middle-tier), caches that needed to be kept synchronized, and so on. While all technical problems are soluble, this one was just not feasible to solve within E-Business Suite itself.
Virtualization Changes Things
In an conventional (non-virtualized) architecture, the failure of a specific application tier node would force a logout of all end-users with sessions on that particular node. Any transactions that were mid-stream on that application tier node would have been lost.
On a virtualized platform, end-user sessions can be migrated from one machine to another without the end-user noticing. OVM's live migration feature has some requirements, including the need to have look-alike machines on same subnet. These requirements are discussed in detail in:
Oracle VM also currently restarts the VM if the Virtual Machine Server fails, which would mean the end-user session does need to be restarted. We expect that these behaviors should improve over time.
Your Feedback is Welcome
This concludes my mini-series on virtualization and the E-Business Suite. We're extremely interested in hearing about your use cases and your experiences with our new templates and virtualization kit. Tell us what you think via our new OVM Templates discussion forum.