- Are there any scenarios that thread is more appropriate than fiber?
- On what scenarios should I avoid using Fiber?
A fiber should be used when its body blocks very often waiting on other fibers. For long-running computations that rarely block, traditional threads are preferable - http://docs.paralleluniverse.co/quasar/
So for something like multiple network IO threads that all block each other frequently, use fibers. For something more long running which doesn't get blocked as much (i.e. some background task) use a regular thread.
The other thing to consider is integration. Spring integrates well with standard java thread library, but may not with Quasar's library.