TL;DR
Making the Right Choice:
We have walked through the most popular forms of concurrency. But the question remains – when should choose which one? It really depends on the use cases. From my experience (and reading), I tend to follow this pseudo code:
if io_bound:
if io_very_slow:
print("Use Asyncio")
else:
print("Use Threads")
else:
print("Multi Processing")
- CPU Bound => Multi Processing
- I/O Bound, Fast I/O, Limited Number of Connections => Multi Threading
- I/O Bound, Slow I/O, Many connections => Asyncio
[NOTE]:
- If you have a long call method (e.g. a method containing a sleep time or lazy I/O), the best choice is asyncio, Twisted or Tornado approach (coroutine methods), that works with a single thread as concurrency.
- asyncio works on Python3.4 and later.
- Tornado and Twisted are ready since Python2.7
- uvloop is ultra fast
asyncio
event loop (uvloop makesasyncio
2-4x faster).
[UPDATE (2019)]: