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Alex Pakhomov

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since Mar 12, 2001
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Recent posts by Alex Pakhomov

In 2001 there was a winter car race in Finland, and all major European and some American brands were represented. To everyone's surprise, the winner was a humble 100 hp FWD Ford Focus.

I actually own an RWD w/traction control & ABS. It's fine most of the time, but there are a few days in February and March when I'd rather drive something else.

Just my 2 cents
17 years ago
I've driven both forward (FWD) and rear-wheel (RWD)drive on snowy roads. My perception is that FWD with manual transmission is the most stable. AWD automatic makes no sense in the snow even with traction control and ABS.

BMW and Mercedes dealers sell special sandbags to put in the trunk to reduce skidding. I've heard it helps a little.
17 years ago
Is multi-threading a requirement? Looks like you'd be much better off with a "queued" server. Otherwise you'll have a lot of issues with thread synchronization. Normally threads in a threaded server don't interact.
Jekin, are you running your program in a DOS window? If yes, it does not understand VT100 (or other terminal's) control characters. The XTerm window does terminal emulation correctly.
Thanks for the response. I was confused by "in its entiriety" piece.
That made me think that an identification variable used with IN operator
can represent something like a subset of collection.
It is clear from the context of its usage that an id variable represents a single entity, while IN statement defines its allowed range, more or less like a loop variable.
Thanks again.
- Alex
The book's answer to the statement "Identification variables can represent a single value or a collection" is false.
This is a bit confusing. The spec ( says that "an identification variable never designates the collection in its entirety".
Indeed, an identification variable can represent a part of the collection
(using IN operator) which is still a collection, right?
I understand Alex's frustration. Spend $600 and a
lot of time with no red carpet rolled in front of
you. Nevertheless I believe the Architect Certification will eventually play its role in his
and hopefully my life. It guarantees nothing, but
definitely improves chances of being hired.
In the meantime, my cat is playing with my Programmer's Developer's, and Architect's lapel pins. At least someone seems to be happy with it :-)
Thanks for your comments, guys.
I agree that stateful Session Beans are designed to keep the session context in between method invocations. But how scalable they are? Stateless session beans are usually implemented as singletons and therefore are very scalable.
Stateful session beans consume the thread pool and can seriously affect performance.
Now, HTTP connections are stateless and (in our case) slow. Why do we need to keep an active thread on the application server for each Web user (thread pool permitting)?
As for the Swing client, it can be designed to be
a bit "fatter" and keep its session context, including the "shopping cart" of itineraries.
Of course, E10000 is a quite a bit of a machine, and if it's beefed up to 64 CPUs and 64 GB of memory, it can compensate for some architectural inefficiences :-)
Hello all SCEA aspirants!
I am trying to figure out the best architecture for my EJB front end. These are two options(patterns) I am considering:
1) Session Facade - Stateful Session Beans = actors, their business methods wrap use cases and interface with Entity Beans
2)Stateles CommandBeans perform atomic operations
depending on session context which is kept elsewhere (Servlet Engine and Swing Client)
Obviously (2) scales much better on the EJB side and extends much easier. However the architecture
for (2) is more complex and requires custom
serialization for the session context. Overall
performance gain of (2) is unclear, especially when both EJB and Web servers run on the same box.
Simply speaking, what is the best place to keep the session context:
stateful EJB or Servlet Engine?

Originally posted by hanumanth reddy:

I am planning to clear java developer examination .
Can any one suggest me from where should i start .

Important things to learn are threads, RMI, and Swing.
If you feel comfortable with these three, go ahead and download the assignment.

Originally posted by Rudy Yeung:
What about your client side? I mean do you have another database interface for the client side, but then as a whole you do not need to throw a general Exception? For me, I have a database interface throwing Exception (just a general exception), which is extended by both the remote and local database interface. The remote database interface will throw the remote and database exeptions, whereas the local database interface will throw only the database exception.

I [re]used the RMI server IMPLEMENTATION class to connect to the database in local mode. When something is wrong in
the database the implementation class methods throw the RemoteException anyway. It saves a lot of coding time.
- Alex