|Service Oriented Enterprise
Saturday, May 08, 2004
WS-REST Mark Nottingham entered the Matrix in search of the spoon.
First, I tip my hat to Mark for tackling a complex issue.
Mark points a handful of things out:
1. A single http request is indeed synchronous
2. The http request doesn't have to block for the end result, instead it can block for an ACK or a fault code
3. Two http requests can be combined to create an asynchronous message exchange pattern
4. Pub/sub can be simulate via polling.
So far, so good.
He continues, to say:
5. One can hold open a TCP connection and use event looping to minimize the resource consumption issue.
Ok, this is an interesting one. In my opinion, there are some problems here:
1. It assumes that not only the end server utilizes a specific mechanism (event looping), but also every intermediary between the client and the server.
2. Connection oriented protocols don't work well when the server crashes (all connections must be reestablished; kiss your performance gain bye-bye).
3. Clustering connection oriented protocols (IMHO) is more cumbersome than connection-less protocols.
Then he introduces the peer-to-peer model, where the client has a well-known address and continues on to acknowledge the firewall/NAT issue. Very good.
Ultimately Mark points out that many people hear 'http' and think synchronous - which is right and wrong. Yes under the covers the application blocks, but not necessarily for the 'answer'. He also states that people should consider the level of abstractions that they need (describe the message exchange versus describe the implementation). I agree. He ends his post with noting that modern distributed computing practices require the ability to describe the interface and the message exchange pattern, then he goes on to mock one up.
In my opinion, Mark has blasted past the issue of 'WS-I' style versus 'RESTifarian' style and is well on his way to finding the best-of-breed. This will be one to watch. posted by jeff | 8:09 AM
Friday, May 07, 2004
Emerging Technologists Every solution creates a new problem. As soon as a solution is introduced emerging technologists begin thinking about the new problems and the means to solve it. They jump right over the 'current' problem and begin attacking the issues that haven't occurred to the majority.
Over the years, I've created a few broad categories that I use to describe the 'emerging' people:
Spotters - a spotter is someone that scans the available technical literature looking for the next big thing (a spot).
Weavers - a weaver is a person that combine multiple 'spots' into a candidate solution (a weave).
Appliers - an applier is a person that takes a well known problem and applies a new candidate solution towards the problem (an application).
Inventors - an inventor is a person that illuminates a new alternative solution to a well known problem (an invention).
Evangelist - an evangelist is a person that makes persuasive arguments in support of a new spot, weave, application or invention.
Referee - a referee is a person that attempts to mediate the 'emerging' people and their solutions.
What are you? posted by jeff | 7:36 AM