What is Search Engine?

Search Engine

A program that searches documents for specified keywords and returns a list of the documents where the keywords were found. Although search engine is really a general class of programs, the term is often used to specifically describe systems
like Google,  Alta Vista and Excite that enable users to search for documents
on the World Wide Web and USENET newsgroups.

Typically, a search engine works by sending out a spider to fetch as many documents as possible. Another program, called an indexer, then reads these documents and creates an index based on the words contained in each document. Each search engine uses a proprietary algorithm to create its induces such that, ideally, only meaningful results are returned for each query.

What Is Google Application Search Engine?

  • Via John Battelle, Rick Skrenta’s remarkable piece on what Google have actually built. They don’t just have the world’s best search engine, they have the world’s largest and most scalable platform for developing huge web-based applications.

  • Google has taken the last 10 years of systems software research out of university labs, and built their own proprietary, production quality system. What is this platform that Google is building? It’s a distributed computing platform that can manage web-scale datasets on 100,000 node server clusters. It includes a megabyte, distributed, fault tolerant file system, distributed RPC code, probably network shared memory and process migration. And a data center management system which lets a handful of ops engineers effectively run 100,000 servers. Any of these projects could be the sole focus of a start up.

  • Google App Engine lets you run your web applications on Google's infrastructure. App Engine applications are easy to build, easy to maintain, and easy to scale as your traffic and data storage needs grow. With App Engine, there are no servers to maintain: You just upload your application, and it's ready to serve your users.
  • You can serve your app from your own domain name (such as http://www.example.com/) using Google Apps. Or, you can serve your app using a free name on the appspot.com domain. You can share your application with the world, or limit access to members of your organization.
  • Google App Engine supports apps written in several programming languages. With App Engine's Java run time environment, you can build your app using standard Java technologies, including the JVM, Java servants, and the Java programming language—or any other language using a JVM-based interpreter or compiler, such as JavaScript or Ruby. App Engine also features a dedicated Python run time environment, which includes a fast Python interpreter and the Python standard library. The Java and Python run time environments are built to ensure that your application runs quickly, securely, and without interference from other apps on the system.
  • With App Engine, you only pay for what you use. There are no set-up costs and no recurring fees. The resources your application uses, such as storage and bandwidth, are measured by the gigabyte, and billed at competitive rates. You control the maximum amounts of resources your app can consume, so it always stays within your budget.
  • App Engine costs nothing to get started. All applications can use up to 500 MB of storage and enough CPU and bandwidth to support an efficient app serving around 5 million page views a month, absolutely free. When you enable billing for your application, your free limits are raised, and you only pay for resources you use above the free levels.

 Google Application Environment


  • Google App Engine makes it easy to build an application that runs reliably, even under heavy load and with large amounts of data. App Engine includes the following features:
  1. dynamic web serving, with full support for common web technologies
  2. persistent storage with queries, sorting and transactions
  3. automatic scaling and load balancing
  4. APIs for authenticating users and sending email using Google Accounts
  5. a fully featured local development environment that simulates Google App Engine on your computer
  6. task queues for performing work outside of the scope of a web request
  7. scheduled tasks for triggering events at specified times and regular intervals
Your application can run in one of two runtime environments: the Java environment, and the Python environment. Each environment provides standard protocols and common technologies for web application development.

Google Accounts

  • App Engine supports integrating an app with Google Accounts for user authentication. Your application can allow a user to sign in with a Google account, and access the email address and displayable name associated with the account. Using Google Accounts lets the user start using your application faster, because the user may not need to create a new account. It also saves you the effort of implementing a user account system just for your application.
  • If your application is running under Google Apps, it can use the same features with members of your organization and Google Apps accounts.
  • The Users API can also tell the application whether the current user is a registered administrator for the application. This makes it easy to implement admin-only areas of your site.

In this Running Gen ration GOOGLE is very famous and useful Search Engine. 
No comments:
Subscribe to: Posts (Atom)