Oracle CEO Larry Ellison took multiple jabs at Salesforce.com in the welcome keynote at OpenWorld yesterday.

He said it was old, not fault tolerant, not elastic, and built on a bad security model since all customers share the same application. “Elastic” in this context means able to scale on demand.

Ellison was introducing Oracle’s new cloud-in-a-box, the Exalogic Elastic Cloud. This features 30 servers and 360 cores packaged in a single cabinet. It is both a hardware and software product, using Oracle’s infiniband networking internally for fast communication and the Oracle VM for hosting virtual machines running either Oracle Linux or Solaris. Oracle is positioning Exalogic as the ideal machine for Java applications, especially if they use the Oracle WebLogic application server, and as a natural partner for the Exadata Database Machine.

Perhaps the most interesting aspect of Exalogic is that it uses the Amazon EC2 (Elastic Compute Cloud) API. This is also used by Eucalyptus, the open source cloud infrastructure adopted by Canonical for its Ubuntu Enterprise Cloud. With these major players adopting the Amazon API, you could almost call it as standard.

Ellison’s Exalogic cloud is a private cloud, of course, and although he described it as low maintenance it is nevertheless the customer’s responsibility to provide the site, the physical security and to take responsibility for keeping it up and running. Its elasticity is also open to question. It is elastic from the perspective of an application running on the system, presuming that there is spare capacity to run up some more VMs as needed. It is not elastic if you think of it as a single powerful server that will be eye-wateringly expensive; you pay for all of it even though you might not need all of it, and if your needs grow to exceed its capacity you have to buy another one – though Ellison claimed you could run the entire Facebook web layer on just a couple of Exalogics.

In terms of elasticity, there is actually an advantage in the Salesforce.com approach. If you share a single multi-tenanted application with others, then elasticity is measured by the ability of that application to scale on demand. Behind the scenes, new servers or virtual servers may come into play, but that is not something that need concern you. The Amazon approach is more hands-on, in that you have to work out how to spin up (or down) VMs as needed. In addition, running separate application instances for each customer means a larger burden of maintenance falling on the customer – which with a private cloud might mean an internal customer – rather than on the cloud provider.

In the end it is not a matter of right and wrong, more that the question of what is the best kind of cloud is multi-faceted. Do not believe all that you hear, whether the speaker is Oracle’s Ellison or Marc Benioff from Salesforce.com.

Incidentally, Salesforce.com runs on Oracle and Benioff is a former Oracle VP.

Postscript: as Dennis Howlett observes, the high capacity of Exalogic is actually a problem – he estimates that only 5% at most of Oracle’s customers could make use of such an expensive box. Oracle will address this by offering public cloud services, presumably sharing some of the same technology.