The acquisition of 3Tera by Computer Associates signals an intent to move beyond traditional Systems Management, into something that may almost be viewed as Operating System: a layer of software called AppLogic that sits above the virtualization stack, and provides a consolidated abstraction against which composite applications may be built within the Cloud.Â Essentially the AppLogic layer deals with the nuts and bolts of configuring and connecting virtual machines, all you do is choose from a menu of virtual appliances you want, and use a visual interface to show how the appliances interconnect at a software level.
For those unfamiliar with 3Tera (and this type of solution is by no means mainstream yet), Eucalyptus is possibly the closest comparison we have looked at here at TVP.Â Â Whereas Eucalyptus has driven an Open SourceÂ strategy around an API-level equivalence with the Amazon Cloud API and a relationship with Ubuntu,Â 3Tera’s strategy has involved providing some very flashy tooling, and some useful (and annoying to configure manually) virtual appliances and pre-built application structures that come out of the box and glue together well.Â They’ve also got some GUI tools for monitoring.
The virtual appliances appear as little configurable boxes that you glue together with lines.Â Â Â You can build virtual appliances that plug into the framework, and you can take an existing virtual appliance, log into it and do whatever you like to it (including kernel modifications). The externally-visible IP addresses (i.e. those that connect to the internet) do need to be configured.Â The internal interfaces are managed for you.Â The physical location of appliances on machines is not something you care about.Â You allocate resources to the Cloud and then either configure the resource allocated to each appliance separately (as you would in traditional virtualization tooling), or configure a composite application as a single entity.Â Â An application is expected to scale to around 40 servers, although you will have to define the software level of the scaling – e.g you need to tell it how many instances of the web server it is supposed to create.
The whole thing seems to be based on open source technology, specifically Linux which is used in most of the Virtual Appliances.Â It isn’t entirely clear if the distributed kernel which provides the abstraction layer is proprietary or open source, or the relationship with Windows, and how to use Windows in virtual appliances.
3Tera has gone round building hosting company partnerships, so you can get this from lots of different virtual datacenters.Â If you’re tempted it’s worth trying it out that way. If you’ve spent some time building LAMP stacks or a more complex application infrastructure on top of VMware or Xen, it looks like it would make your life much easier.Â On the other hand, it could just be that it does the easy things quickly and leaves you the hard things to do in the same old manual way, so the actual productivity gain is limited.Â The other issue is that whilst the hypervisor vendors don’t currently supply you with all this, there’s no doubt they are heading that way, so this layer may make more sense as a layer in the Operating System, rather than something you buy from a Management Tools vendor.