I recently used mongoDB for a project and I am quite impressed with its speed and MongoDb is a popular no-sql database .For huge data Google uses its own database structure i.e Big table mongo db has too many pros over MySQL but also cons.It all depends on what your pupose would be.MongoDb is definitely not a RDBMS hence in a case where you would be using too many joins to get your data from different tables you need a sql database . In a project where you have huge number of records and constants writes and reads mongoDb would be a write option for you.
In mongoDB collection is similar to the tables in collection and collection would contain several documents which is a BSON document values are stored corresponding to a key and key may vary from every document in a collection this makes it flexible for varying type of data. If your DB is 3NF and you don’t do any joins (you’re just selecting a bunch of tables and putting all the objects together, AKA what most people do in a web app), MongoDB would probably kick ass for you. But If I need ACIDity, I won’t use NoSQL.
Tornado is a Python web framework and asynchronous networking library, originally developed at FriendFeed. By using non-blocking network I/O, Tornado can scale to tens of thousands of open connections, making it ideal for long polling, WebSockets, and other applications that require a long-lived connection to each user.
whenever u need to pass on to hundreds of clients at once no need to get request this follows a push mechanism,and as it is built on python is pretty fast too.Check it out on developers.facebook. com /opensource
j2ee vs .net
Though the debate over the superiority of .Net versus that of Java 2 Platform, Enterprise Edition (J2EE) seems a hot topic in today’s technology circles, many people believe it is simply a marketing battle of little consequence. Marketing battle or not, the debate’s effects will one day prove critical in software evolution. Thus, Sun Microsystems’ and Microsoft’s executive teams have committed significant marketing budgets in an effort to gain advantage. Should Microsoft lose this battle, the operating system might simply become a lifestyle choice. Sun’s victory could one day enable software to run on any operating system, causing Microsoft’s dominance in operating systems to slowly fade as other operating systems, capable of running the same software, come to market. On the other hand, should Microsoft succeed, it will further entrench its technology suite as the de facto standard for the foreseeable future. In this article, we compare the J2EE and .Net technologies to help you decide which one is worth the investment.