Monday, April 21, 2008

Does VMWare Workstation 6 crash when you power on?

I've been having a major VMWare problem on my Fedora 8 x64 workstation. Creating a new VM was no problem. Whenever I tried to power it on, however, my entire system would lock. Being the demanding, unreasonable jerk that I am, I wasn't willing to accept this behaviour ;-)

I found this post (I was amused watching the two posters bicker over 64 bit VMWare) which pointed me in the right direction. I unloaded  the kvm_intel and kvm modules. After that, my vm powered on like a champ!

So, if VMWare Workstation 6 is crashing your linux box, see if running these commands helps:

sudo rmmod kvm_intel

sudo rmmod kvm_amd

sudo rmmod kvm

P.S. I've added learning about KVM to my homework list. This link is a start.

Saturday, April 19, 2008

REST is Gathering Support

Udi Dahan, an active enterprise software community member, posted a great podcast on using Rest for large scale projects.

Here's my summary:

  1. Most of the on-line REST examples focus on simple active record, crud-ish systems. The resources are things like Customer, Catalog, Catalog item, Order, etc.

  2. Business operations can be treated as resources too. Transfer balance, Sunset product, Change name just happen to be resources that affect more than one entity. The classic Transfer balance operation, for example, affects two bank accounts. The transfer balance operation itself, however, has its own attributes such as transfer initiation date, transfer initiator, transfer approver (perhaps), etc.

  3. RESTful HTTP GETs leverage the extensive caching infrastructure that the Web is built upon.

Does this mean that every large system should be RESTful? No. Does this mean that REST deserves serious consideration when designing SOA based systems? Absolutely yes.

At the end of the podcast, he mentions his concern for a lack of REST service description tools. The community is working on this. Check out WADL for details.