• 500 Mb process

• 100 ms response time

• 70% serving requests

• 7 RPS

• 5% CPU usage

• 500 Mb process

• 103-105 ms response time

• 100 RPS

• 70% CPU usage

• Latency: 50 ms → 3-15 sec

• Response: 50 ms → 0.5-1 sec

• Slow: 0.04 / 10 RPS

async def combine_things(http, u1, u2):
     value1 = await get_json1()
     value2 = await get_json2()
     return combine(value1, value2)

def combine_things(http, u1, u2):
     (value1, value2), _ = await asyncio.wait([
         get_json1(u1),
         get_json2(u2),
     ])
     return combine(value1, value2)

Nginx → Backend

with aiohttp.Timeout(10):
    async with session.get(url) as response:
        assert response.status == 200
        return await response.read()

• 100 input connections

• 10 db connections

asyncio.async ≠ celery

Pool Size = 1

Browser → Gateway → Backend

async def transfer(amount, payer, payee, server):
    if not payer.sufficient_funds(amount):
        raise InsufficientFunds()
    payee.deposit(amount)
    log_transfer(amount)
    payer.withdraw(amount)
    await server.update_balances([payer, payee])

async def transfer(amount, payer, payee, server):
    with lock(payer, payee):
        if not payer.sufficient_funds(amount):
            raise InsufficientFunds()
        payee.deposit(amount)
        log_transfer(amount)
        payer.withdraw(amount)
    server.update_balances([payer, payee])