However, what has spawned from that original proposal is a wide ranging, but thoughtful discussion of what is needed to allow for an open market for compute resources in the cloud. Participating are several of the vendors supplying various services for Amazon EC2 today (and, I'm sure, a wide range of others in the future), and several end users of primarily "Computational Grid" technologies.
I sent several responses. Here are some highlights:
- Mike Culver pointed out that
"Condor (http://www.cs.wisc.edu/condor/) is a project that enables this sort of scenario. But in so doing, things go full sircle [sic], and suddenly the paradigm is the old days of mainframe computing where the notion of "job" is separate from the underlying computing resource."I replied
"I hate the notion of every software executable being a "job". [With most] high availability applications running additional instances [of "permanent" processes] in excess capacity at another site is a distinctly possible scenario.The idea of a "job" is just not applicable to many user-facing applications.
I prefer the term "software payload" to describe what gets moved from cloud provider to cloud provider, at least at the HaaS level."
- Larry Ludwig of hosting provider Empowering Media notes
"Application scaling IMHO will alwaysAnd I agree, adding
involve a mixture of automated systems and programing changes to the
application. I don't think this aspect of can ever be
The typical "throwing hardware at it" works up to a point and in will be no different since the a cloud system is still based upon
the . There is a point where it becomes more than a
sysadmin/scaling challenge. Programming changes will need to made to the
specific application. What scales to X, won't scale to Y because of a
"I see two architectural problems to be managed when building an application for the cloud:I blog extensively about software fluidity in these posts.
- Scalability - which you cover below
- Fluidity - which is the ability to move an application, *application
tier* or service between cloud infrastructures without rewriting or
reconfiguring the software payload"
- Geoffrey Fox notes that much work has been done to analyze and design Computational Grid economies. I assumed that Geoffrey was taking about grid computing models based on splitting up "jobs", so I noted:
"The problem is partially that Computational Grid computing is a subclass of theIn other words, I'm not sure how far people have gone to analyze enterprise computing on a grid versus just HPC, etc. metrics and standard problem. See earlier notes about long running processes versus "jobs"."