- published: 25 Apr 2016
- views: 1
Elvin is a event routing service using a publish/subscribe event delivery model. It was originally developed at the Distributed Systems Technology Centre, an Australian Co-operative Research Centre based at the University of Queensland which operated from 1992 until mid 2006.
Elvin is most distinguished from other such systems by its support of a sophisticated content-based subscription system. Elvin clients subscribe to events using a language that resembles C boolean expressions. For example:
This expression selects messages that have a field named Department with a string value matching "IT" and a Percent-Disk-Free field with an integer value less than or equal to 10. The Elvin subscription language supports a range of operations for matching numeric and string values, including the use of regular expression matching.
Elvin is oriented around providing a fast, flexible event service that can be federated to form wide-area event notification networks. In order to achieve these goals it does not provide persistence, durability or guaranteed delivery. Elvin can thought of as providing a middle ground between low-level network multicast and higher-level, more complex, event brokers such as JMS.
It dawned on me
That basically
They have put a price on everything.
In a world of greed
And exploiting needs
Some are cashing in, while others bleed.
If I sung out of tune would it sell now?
If I sung out of tune would it sell?
The relevance of the question's unclear now
The big picture's as scary as hell.
It's do or die to survive
In this day and age to stay alive.
When the top boys fight
One's left one's right
The streets become a stage
Actor am I?
If I sung out of tune would it sell now?
If I sung out of tune would it sell?
Focus on the small things and then you fail
To see that we're not doing so well.
Am I alone here
Or am I the only one who sees in different tones?
Somehow we've all adhered
To believe in everything that we are shown.
One mans views today makes
Front page news tomorrow
Injecting doubt to talk about.
It'd be no surprise
If this world was designed