1. Is a Servlet Context is something private to the servlet who has created it?
There is only one ServletContext object per web application. All servlets and JSPs of that web application have access to the ServletContext object.
2. Is it possible to access an attribute from servlet context in a servlet which has been
previuosly set by another servlet.
Yes. You can consider the ServletContext object as a repository of "global" data for your web applications. However, the set/getAttribute() methods are not synchronized, so be careful.
3. What's the life cycle for the Servlet Context attribute?
Unlike a servlet, which can have many instances, a ServletContext attribute remains bound to the ServletContext object as long as the ServletContext object itself exsts, unless it is explicitly unbound by removeAttribute().