All the WCF calls demonstrated throughout this book share two
constraints. First, the port or the pipe assigned to the service must be
available. The application developer or the administrator literally has to
guess or have some way of knowing the port or the pipe is not used by any
other application on that machine. TCP port sharing can alleviate this
problem, but does not help with the second constraint: the client must a
priori know the address of the service endpointsnot just the port number
or the pipe name, but also the name of the service machine (in the case of
It would be great if the service could use any available address,
decided upon at runtime. In turn, the client would need to discover that
address at runtime. In fact, there is even an industry standard-based
solution that stipulates how that discovery takes place. That solution,
called simply discovery (and its supporting
mechanisms), is the subject of this appendix.
Towards the end of 1799, Turner's outstanding talents received official recognition with his election as an Associate Royal Academician.
In 1801, he created a sensation at the Academy with a marine subject in oil, the so-called Bridgewater Seapiece whose full title is Dutch Boats in a Gale: Fishermen endeavouring to put their Fish on Board.
Largely as a result of that impact, he was elected a full Royal Academician in 1802, at the age of just twenty-six. He was the youngest Academician to have been elected to date.
Turner's new status guaranteed him an audience, for Academicians enjoyed the automatic right to display up to eight works in the annual Exhibition.
Later in 1802, Turner took advantage of the brief peace between Britain and France to visit Switzerland. For years afterwards he drew from the sketchbook material gathered there.
In 1806, Turner embarked upon a major mezzotint engraving project, the Liber Studiorum. Eventually he made one hundred sepia watercolours for this project, of which seventy-one were reproduced by means of engraving. The following year Turner was elected the Royal Academy Professor of Perspective.
Jay is a skillful guitar player. His rock band is hired to play at local events every once in a while. He loves performing and looks forward to earning more money as a musician. Jay’s dad is very proud of his son’s accomplishments.
But he warns Jay that he needs a reliable source of income.
“You need a vocation,” he tells his son. “Find a career you can depend on for a steady paycheck.”
Jay doesn’t know how to find a vocation. He mentions his problem to his uncle, Cody. Cody is an EMT
(emergency medical technician). He had learned his job in vocational courses at the local community college.
He tells Jay about the special training he’d received. He was thrilled to actually be able to save people’s lives!
Cody’s best friend, Eduardo, took auto shop in high school. Then he went on to learn engine rebuilding at a state vocational education program.
Eduardo is now a well-paid mechanic at Al’s Auto Clinic. Eduardo’s girlfriend, Angie, is a hairstylist. She learned her vocation at a private academy she found advertised in the paper and on TV.