Veritas is buying a supplier that sounds like a spelling mistake. Ejasent supplies technology to enable applications to be moved between servers in a multi-tier environment. That is, applications at a particular tier level can be moved to different servers in the same tier.

This is particularly useful where applications in a tier assume the existence of a connection to other applications above or below them in a tier. The network pipes between the tiered applications carry status and messaging information for transactions of various kinds. These allow us users to carry out, for example, Internet purchase transactions where the transaction has to have all parts of the total application stack across the tiers: web front end; messaging app; business logic; database backend; must be present and correct for the transaction to complete through its several steps.

If any of the network pipes or tiered apps go out of action then the transaction fails and has to be restarted. Ejasent's UpScale technology enables an application at a tier level to be moved to another server, in the middle of one or more transactions, without having to fail and restart all the ongoing transactions. There is no loss of service from the end-user's point of view and the app transfer time is generally much less than 10 seconds.

How is it done? Why is Veritas interested? How does this differ from EMC's VMware?

How is it done?
UpScale captures a snapshot of an entire application stack and stores it. When the application is needed it is instantiated on the next available server in real time, typically a few seconds. This is the UpScale standard edition's capability. Using stored policies when the running applications meets some scaling limit, or its host server needs maintenance, the running app can be moved to an adjacent (ejasent - geddit) server at the same tier level without connected applications in the totality of the multi-tiered application stack being adversely affected. This is what the advanced edition of UPScale carries out.

The Ejasent software, an application management framework, pools and manages the resources of servers within an enterprise to create a virtual single server, removing the need for enterprises to dedicate servers to specific applications. That way, when one application is no longer needed, it can be removed from the server automatically to make room for another application, Ejasent executives say. You need fewer servers to run your set of applications if you no longer have to dedicate particular servers to particular applications.

It is a truism that applications can only be moved between homogeneous servers. There is, as yet, no possibility of taking a Windows binary and running it on a Linux system. Heterogeneous server pooling is a different ball game and something we can forget about for a few years.

To say as Ejasent and Veritas do, that applications are virtualised is potentially confusing. When storage or RAM is virtualised then any disk or memory element can hold any piece of data. With Ejasent's application virtualising, end-users are still dealing with a specific single application instance. It has, merely, been moved from one server to another and the connection metadata (state, persistence, etc.) captured by a connection filter to hide the closure and re-instantiation of the application on another server from users and other applications in connected tiers. It is a very limited, if powerful, kind of application virtualisation.

The software is based on patent-pending technology that separates the application from the hardware by taking a snapshot of the application that can then be distributed to servers with appropriate capacity. The technology also includes a feature called "micro-metering", which enables technology managers to track usage at the most granular system levels.

Why is Veritas interested?
Veritas has a substantial set of cluster management technologies. It knows grid or utility computing is coming and is urgently extending its product capabilities. Ejasent's cluster capability must have been seen as a natural fit to existing Veritas products. Ejasent itself will become part of Veritas' High Availability/Clustering group. Both UpScale and MicroMeasure, Ejasent's server resource usage measurement tool, will be integrated into the Veritas CommandCentral product.

Rajeev Bharadhwaj, co-founder and chief technology officer of Ejasent, said, Ejasent's application virtualisation technology is highly complementary to Veritas' products and it will become an important building block as Veritas enables utility computing.

For now Veritas is pushing the server maintenance message. Mark Bregman, Veritas' exec VP of product operations, said, "Live application migration can cut server maintenance and upgrade time from hours to minutes, freeing valuable IT resources to work on other projects while at the same time improving application availability for end-users."

Veritas appears to have the only multi-tier capable server and application virtualisation technology. Ejasent is an IBM autonomic computing partner and thus looks to have a relationship with IBM which can be developed further. Veritas expects to deliver UpScale and MicroMeasure software in the second quarter of 2004. UpScale will be available initially on Solaris, with a Linux version set for release in early 2005. MicroMeasure runs on Solaris, Windows, Linux and HP-UX. Veritas has much work to do to spread UpScale technology to the various parts of the server market.

How does this differ from VMware?
EMC has bought VMware to provide server virtualisation with multiple logical servers running applications in a single physical server. There is no current capability to move running applications from one server partition to another. VMware allows you to instantiate applications on logical servers. Ejasent's UpScale enables, in its standard edition, the instantiation of applications on actual servers and, in its advanced edition, the movement of running servers from one server to another.

But Ejasent also allows a server to be setup so as to run multiple application instances, similar to VMware's capability. Score one to Veritas. The idea of converging VMware and UpScale functionality will no doubt be of pressing interest to EMC. Any other supplier of blade server, utility computing, grid or clustered computing HW or operating software will also be intensely interested in this general technology. It seems to be an important part of coming utility-style datacentres. Let's include HP, IBM, Microsoft and Sun in this group. The heavyweight suppliers of technology in the server market just got another technology to focus R&D dollars on.

Microsoft is working with Citrix partner Softricity on its own form of application virtualisation. This is equivalent to the VMware dedicated partition idea but apparently carried out with fewer O/S resources. As our feature states, 'This sandbox approach even allows a PC to run different versions of the same application at the same time, for example Microsoft Office 97 and 2003.' However there is no ability to cope with tiers and the maintenance of persistent connections.

We're reached the stage now where management of applications is becoming more and more complex, perhaps to the point where it is beyond the capability of the average IT administrator to understand what is happening at any specific point in time. We're building multi-tiered server and storage infrastructures the bits of which we understand but the totality of which is beginning to exceed our grasp. I guess we look forward to much more intelligent automated app failure tools.