Hey Manish -
These are fun questions
First off, I'm guessing that you're talking about page 103 when the servlet with the Fez hat on mentions the "secret handshake".
This is just kind of a joke (ok, maybe it's a bad joke :roll: ), but a lot of times when you join a private club they teach you a "secret handshake", then, if you meet another club member on the street you can
exchange the club's "secret handshake". So, all we're really saying is that there is a moment when an object is promoted from being a plain old object, to being a "Servlet". And once it's a servlet it can do special, "secret" things with the container that only servlets can do.
Your second question is about scalability. I'm guessing that you're talking about page 707, and the discussion of the hardware used to support BIG web sites. As you know, one of the first things that happens from a hardware perspective when you start scaling up a web site, is to create "tiers". You might for instance have a "web tier" which handles the requests from the internet, then you might have the "business tier" which does the backend processing, talking to databases and such. Each tier can be scaled as necessary to handle more volume. So here's a little pop quiz:
Which scaling approach is considered "vertical" and which is considered "horizontal"?
- Adding more servers to the web tier is _____________ scaling
- Adding adding RAM to an existing server is ____________ scaling
HTH
Bert
Adding more servers is called "horizontal" scaling