Python Bottle + Javascript fetch 每秒 20 个请求的瓶颈在哪里？

Question

在其他测试中，我最终进行了以下测试：在 Python Bottle 服务器和带有 JS 的浏览器客户端之间每秒仅触发并处理 20 个 HTTP 请求。

为什么它无法成功处理每秒 20 个请求（在普通 i5 计算机上）：以下代码是否存在已知瓶颈？

import bottle, time
app = bottle.Bottle()

@bottle.route('/')
def index():
    return """<script>
var i = 0;
setInterval(() => {
    i += 1;
    let i2 = i;
    console.log("sending request", i2);
    fetch("/data")
        .then((r) => r.text())
        .then((arr) => {
            console.log("finished processing", i2);
        });

}, 100);
</script>"""

@bottle.route('/data')
def data():
    return "abcd"

bottle.run(port=80)

sending request 1
sending request 2
sending request 3
sending request 4
finished processing 1
sending request 5
sending request 6
sending request 7
finished processing 2
sending request 8
sending request 9
sending request 10
finished processing 3
sending request 11
sending request 12
sending request 13
finished processing 4
sending request 14
sending request 15
sending request 16
finished processing 5
sending request 17
sending request 18
sending request 19
...

为什么已经是第 19 号请求，而我们只处理完第 5 个请求？

每个请求会丢失 50 毫秒，导致程序无法保持正常速度：

sending request 1
finished processing 1
sending request 2
finished processing 2
sending request 3
finished processing 3

？

Answer 1

gevent

使您的代码按预期运行。仅使用 gevent 的猴子补丁功能，无需异步重写：

from gevent import monkey

monkey.patch_all()
import bottle

app = bottle.Bottle()


@bottle.route('/')
def index():
    return """<script>
var i = 0;
setInterval(() => {
    i += 1;
    let i2 = i;
    console.log("sending request", i2);
    fetch("/data")
        .then((r) => r.text())
        .then((arr) => {
            console.log("finished processing", i2);
        });

}, 100);
</script>"""


@bottle.route('/data')
def data():
    return "abcd"


bottle.run(host='0.0.0.0', port=80, server='gevent')

浏览器控制台输出：

sending request 158
(index):10 finished processing 158
(index):6 sending request 159
(index):10 finished processing 159
(index):6 sending request 160
(index):10 finished processing 160
(index):6 sending request 161
(index):10 finished processing 161
(index):6 sending request 162
(index):10 finished processing 162
(index):6 sending request 163
(index):10 finished processing 163
(index):6 sending request 164
(index):10 finished processing 164
(index):6 sending request 165
(index):10 finished processing 165
(index):6 sending request 166