As Web sites get more and more interactive, customized and dynamic, developers
turn to technologies that allow them to do more than the first-generation tools
can handle. One technology that is rapidly replacing CGI and Perl scripts as
the preferred choice for dynamic Web sites is Java Servlets.
July 18, 1998
Ask Marc Mnich, developer of the Virtual Memorial Web site. "[The] initial design of the system was CGI-based using perl and the same database backend. I have found the Java
Servlets to be far superior in terms of performance (mainly due to threading and
JDBC) and stability," he says. The Java Servlet API is part of the Java
specification in JDK 1.2. A Servlet is executed on the server, like GCI scripts,
but instead of creating a new process for each request, all Servlet requests are
handled in the same process by separate threads. Servlet-based applications
therefore avoid a lot of overhead processing. Using threads instead of processes
also means that a Servlet can keep data persistent between requests. For
instance, a pool of database connections can be shared by multiple requests and
frequently requested information can be cached. Threading and persistence makes
it much easier to develop high performance solutions.
A Servlet-based solution is a standards-based solution. It means it works with what
you have today and scales to what you need tomorrow. The Servlet API is
supported natively by a number of Web servers, such as JavaSoft's Java Web
Server (JWS) and O'Reilly & Associates' WebSite Pro. For other popular Web
servers, like Netscape's Enterprise Server and FastTrack Server, Microsoft's
Internet Information Server (IIS), StarNine's WebSTAR, and Apache, there are
Servlet Engine add-ons from companies like Gefion Software, Live Software, New
Atlanta and IBM. Application servers with load balancing and sophisticated
administration features, like ATG's Dynamo and NetDynamics, support Servlets as
well. Since Servlets can use all Java APIs, they are easy to integrate with
other parts of the IT infrastructure. All major databases can be accessed
through JDBC, directory services through JNDI, and advanced distributed services
through RMI and Java IDL.
Performance and scalability are important concerns when selecting a technology
for your Web site development. A popular site can receive an enormous number of
requests per day. With the inherited threading and techniques like database
connection pooling and caching, Servlet-based solutions are well fit to handle
the pressure. "Sony Corp.'s The Station isn't just another Internet site with
games, shopping, and chat groups. It's the largest server-side Java site on the
World Wide Web, receiving 100 million hits a week," reports Bronwyn Fryer in an
article in the January 19 issue of Information Week. At traffix.com, an ad
banner exchange service, Servlets are serving up to 190,000 banners per day.
virtualmemorials.com receives around 50,000 hits per day, most of which are for
servlets. Servlets are used to power Proxicom's solutions for online
communities, with features like discussion forums, chat rooms, calendars and
more. "Our application is capable of returning a 'dynamic ptml page' within a
few hundredths of a seconds," says Rich Andrews at Proxicom, Inc. Servlets also
deliver membership services at developer.java.sun.com, provide access to contact
information and resumes at www.qcommand.com, sell software at javashop.sun.com.... The list goes on and on.
If your Web site could do more for you than it does today, take a closer look at
Servlets and Servlet-based products and solutions. The technology is here today,
providing valuable services 24 hours a day, 7 days a week at a Web site near
you.
Hans Bergsten has worked in the computer industry for 18 years, with everything from IBM mainframes to PCs.
