HOW TO : High traffic db

Though this can be very abstract question, please show me any proper direction.

DB design and replication configurations f开发者_开发知识库or Twitter-like webapp (heavy inserts & reads).

For a very high loads, you might consider NoSQL databases. This solution works well, when you mostly need to read data, and your data logic is not to complex. NoSQL solutions can be times faster then relational databases, when properly configured.

If you want to go with MySQL, this question is too abstract. There are tons of things you need to think about:

1. proper table structure
2. proper indexing
3. caching
4. normalization and denormalization
5. your queries
6. clustering

Google all of these, to understand why those questions are important. If you are serious about getting the best out of MySQL performance, I really recommend "High performance MySQL" - this book is terrific.