I believe that both of these questions are completely off-topic.
> Question 1:
> How does an elementary Singleton pattern based Object behave
> in a multi-threaded environment? What is this phenomenon called? How do you
> make such a Singleton Object thread safe?
There are several excellent articles on the net with respect to this specific
question, as well as how it relates to synchronization of the Singleton's code.
A google search will find these articles for you.
> Question 2:
I also believe, having programmed trading systems for over a decade, that
you will find that there are many existing protocols for accomplishing just
this sort of thing. FIX comes to mind. However, this will depend more on
your environment and clients, than it will on Java technology.
> What are the two methods typically employed to notify remote
> clients distributed over the Internet of events that take place on a
> central server? Like changes in the price of options, market depth, or an
> order
> execution? What are the relative advantages/disadvantages of each of
> these strategies? Specifically, how can they be implemented in Java to
> allow
> for firewall tunneling over HTTP?
