Continuation questions

• How Much Traffic Can Shared Web Hosting (for a Python Django site) support?
• Why do sites like twitter, gawker use #! instead of simple URL? [duplicate]
• Does Redis / Memcached / MongoDB (or any NoSQL systems) support MySQL's ON DUPLICATE KEY UPDATE?
• How do you avoid this race condition in Python / Django / MySQL?
• What exactly makes Erlang process, green thread, coroutine "lighter" than kernel thread? What about context switching that's heavy? [duplicate]
• Is there any way to make Django's get_or_create() to create an object without saving it to database?
• Weird MySQL query plan: why is this query using temporary & filesort? How to optimize it?
• Any open source software for monitoring MySQL performance?
• Does poll/epoll block? How is it different from async IO?
• Python: why can't descriptors be instance variables?

Continuation answers